Biodegradable highly filled thermoplastic composition using starch and nanomodifier

FIELD: chemistry.

SUBSTANCE: invention relates to a biodegradable highly filled thermoplastic composition used in making films and consumer packaging. The composition contains polyethylene, biodegradable filler in form of potato starch, process additives: oligoepoxy ether with molecular weight of 1800-3500 and content of epoxy groups of 2.0-4.0% in nano-form and nonionic and cationic surfactants.

EFFECT: obtained composition has good process parameters, articles made from the composition are biodegradable under the effect of light, moisture and soil microflora.

2 tbl, 6 ex

 

The invention relates to the production of plastics based on polyethylene used in the manufacture of films, consumer packaging, utensils, products for household purposes, used in contact with food and technical purposes.

In a difficult environmental situation, the use of biologically erodible polymeric materials for manufacture of products of mass consumption is a key priority to reduce the amount of solid waste, so as to ensure their rapid decomposition under the action of climatic factors and microorganisms.

One of the possible ways of obtaining biologically decomposable material is a modification of traditional polymers. The combination of a synthetic polymer with natural active filler can give the material a new set of properties.

Such materials are filled system, where as the active filler is starch. The most important quality of these compositions is their ability to degradation under the influence of natural environmental factors: light, heat, microorganisms. Known biologically decomposable packaging material based on starch (France, 2691467, CL. 5 C08J 5/18, B65D 1/10, 65/46, C08L 3/20).

In the last time there was a significant number of patents and scientific public is of icaci, contains information about the use of starch as a filler for imparting polymer compositions biological destructible (U.S. patent 5248702, C08J 9/12, publ. t, No. 4; U.S. patent 5298267, C08J 9/02, 9/12, publ. 03.05.2004, t, No. 1; patent RU 2095379, publ. 30.06.98; patent RU 2180670, publ. 06.01.2000; patent RU 2174132, publ. 23.06.2000; patent 1338405 EPO, MLK VS 67/24, C08J 5/06, publ. 27.08.2003; U.S. patent 6054510, IPC7C08L 63/00, publ. 25.04.2000, patent RU 2363711 C08L 23/06, 97/02, 3/00, C08J 1 1/04).

Company Archer Daniels Midland, USA, developed the concentrate of the brand Poly Clean polyethylene-based to obtain biodegradable films. The concentrate contains 40% starch and oxidized additive, the amount of starch in the final product is 5-6%. The disadvantage of this composition is that biological destruction undergoes only the starch component.

Closest to the technical essence and the achieved result of the present invention is the composition according to the patent of Russian Federation №2418014:

Polyethylene63,5-to 86.4 wt.%
A copolymer of ethylene and vinyl acetate3.0 to 5.0 wt.%
Surfactant0.1-0.5 wt.%
starch 10.0 to 30.0 wt.%
shungite0.5 to 1.0 wt.%

The objective of the invention is the creation of highly filled thermoplastic compositions using biodegradable filler starch products which decompose under the action of light, moisture and soil microflora.

This is achieved by the fact that biologically erodible highly filled thermoplastic composition according to the invention, contains: polyethylene (77,8-13,5) wt.%, biodegradable filler, which is used potato starch (20,0-80,0) wt.%, and processing AIDS, which are used oligopolies with a molecular mass of 1800-3500 and content of epoxy groups of 2.0-4.0% in nanoform (2-5) wt.%, nonionic surface-active substance sintana ALM-2 (0.1 to 1.0) wt.%, the cationic surfactant of the Quaternary ammonium compound type halides alkylpyridine and alkyltrimethylammonium (0.1 to 0.5) wt.%.

According to the invention, as a biodegradable filler, stimulating the process of biological destruction of the final products made from polyethylene, is used potato starch in the amount of (20-80) wt.%.

Used for filling potato starch has the following physical specifications:

Mass fraction of moisture, %:17-20;
Mass fraction of total ash on a dry basis
substance, %, not more:0,3-1,0;
Acidity - the consumption of 0.1 n NaOH solution to neutralize
100 g of dry matter, ml, not more than:6,0-20,0

For the filling you can use the starch of different nature: corn, potato, rice, wheat, etc. But preference is given to potato starch. Grains of potato starch are oval in shape, their size varies from 15 to 100 μm, and the grain structure, mainly amorphous, such starch is easier processing.

According to the invention, as technological additives used oligopolies (thermosetting oligomer). Used as a modifying additive to the polymer, has a high reactivity and can react with various functional groups. A solid substance with a molecular mass of 1800-3500, softening temperature (85-100°C), the content of epoxy groups (2,0-4,0%; content of hydroxyl groups (about 6.5-6.8)%. To achieve the above goal, oligopoly the IDF was used in the form of a nanopowder. The nanopowder algaetoximeter was obtained by ultrasonic dispersion. The most effective ultrasonic dispersion occurs during the processing of plant and animal cells, amorphous substances and aggregation substances of the type of soil and rocks, the splitting of textured materials such as cellulose, asbestos. Ultrasound is the dispersion of powders of various metal oxides (Al2O3, SiO2, TiO2and others). A distinctive feature of this method of obtaining nanopowders is the high homogeneity of the obtained powder of predetermined particle sizes.

Using the modifier oligopolies in the form of a nanopowder, to ensure the introduction of the mixed composition of the filler starch due to the high homogenization of the ingredients of the mixture.

Surfactant was chosen to reflect the necessity of creating a heterogeneous system with specified values of effective viscosity in the selected temperature range processing. Surfactant selected from a cationic surfactant is a Quaternary ammonium compound type halides. The number of aggregations - 169, micellar mass - 62000, KKM, mm to 0.92. This cationic surfactant used in the composition to improve the compatibility of the ingredients and achieve a high degree and homogenization.

Surfactant - sintana (ALM-2), General formula R-O(CH2CH2O)nH, where n=2; R is an alkyl residue containing mainly (12...14) carbon atoms. The number of aggregations - 140, micellar mass - 90000, KKM, mm - 0,24. This nonionic surfactant used in the composition as an initiator of biodegradation.

As the polymer, the role of the dispersion medium, there was used a polyethylene LDPE 15803-020 that have the following characteristics: density, kg/m3- 919,0; MFR, g/10 min under a load of 2.16 kg and 2.0.

This mixed composition has rheological characteristics that meet the requirements of materials for recycling on traditional for plastics equipment (extruder, molding, etc.).

Articles of the proposed compositions have specified performance parameters.

The choice of the optimal proportions of polymer, filler and additives due to theoretical limit of the filling, which is determined by the strength of the interaction at the phase boundary.

The proposed composition is made as follows.

Example 1. 77.8 wt.% polyethylene is mixed with 0.1 wt.% The nonionic surfactants, in high-speed turbomachine within 5 minutes the resulting mixture was added 20 wt.% starch; 0.1 wt.% Cationic surfactant and 2 wt.% algaetoximeter, is stirred in a high-speed turbomachine another 12 minutes The resulting mixture is fed to the extruder for homogenization. The temperature of the melt at the exit of the extruder crosshead (140-150)°C. the resulting Assembly is cooled by a stream of cold air and cut into granules with a size of 3-5 mm From the obtained pellets by the method of cast extrusion at a temperature of 130-145°C produced the film or sheet.

Example 2. The preparation of the composition of example 1. The quantity of starch 80 wt.%, the number of polyethylene 13.5 wt.%, the number of algaetoximeter 5.0 wt.%, the amount of cationic surfactant 0.5 wt.%, the amount of nonionic surfactants 1.0 wt.%. The resulting Assembly is cooled by a stream of cold air and cut into granules with a size of 3-5 mm Pellets obtained from this composition, used for the manufacturing method of molding or injection molding articles of various sizes.

Example 3. The preparation of the composition of example 1. The quantity of starch 50.0 wt.%, the number of polyethylene 45.7 wt.%, the number of algaetoximeter 3.5 wt.%, the amount of nonionic surfactants 0.55 wt.%, the amount of cationic surfactant 0.25 wt.%. The resulting Assembly is cooled by a stream of cold air and cut into granules with a size of 3-5 mm Pellets obtained from this composition, used for the manufacturing method of molding or injection molding articles of various sizes.

Example 4. The preparation of the composition of example 1. The quantity of starch 15.0 wt.%, the amount of polyethylene is 82,8 wt.%, the number of algaetoximeter 2.0 wt.%, the amount of nonionic surfactants 0.1 wt.%, the amount of cationic surfactant of 0.1 wt.%. Of pellets obtained by extrusion, to produce a film or sheet.

Example 5. The preparation of the composition of example 1. The quantity of starch 85,0 wt.%, the number of polyethylene 11.8 wt.%, the number of algaetoximeter 3.0 wt.%, the number NPLV 0.1 wt.%, the amount of cationic surfactant of 0.1 wt.%. The granules are produced by injection molding various products.

Example 6. The preparation of the composition of example 1. The quantity of starch 20.0 wt.%, the amount of polyethylene was 79.8 wt.%, the number of algaetoximeter 0,0 wt.%, the amount of nonionic surfactants 0.1 wt.%, the amount of cationic surfactant of 0.1 wt.%. From the pellets by extrusion is made of a film or sheet.

Table 2 shows the methods for the determination of properties, providing objective of the invention.

td align="center"> GOST 11645-73
Table 2
№ p/pName indicationsTest methods
1The temperature of the processing composition, °CGOST 11645-73
2The melt flow index of the composition (MFR) at a temperature of 190°C and a load of 2.16 kg g/10 min
3Determination of physico-mechanical properties (elongation, %tensile strength, n/m2)GOST 14236-81
4Method for determination of resistance to chemical environmentsGOST 12020-72
5Microbiological stabilityGOST 9.053-75 GOST 9.049-91
6Plastics - evaluation of the maximum aerobic biodegradation and decomposition under controlled conditions decomposition is a Method of analysis of carbon dioxide ASTM Designation: D 6002-96 (Modified method of attack)ISO 14852

Biologically erodible highly filled thermoplastic composition for products containing polyethylene, biodegradable filler, which is used as potato starch, characterized in that as technological additives used oligopolies with a molecular mass of 1800-3500 and content of epoxy groups of 2.0-4.0% in nanoform, and nonionic and cationic surfactants in the following ratio of the components is tov, wt.%:

Polyethylene77,8-13,5
Potato starch20-80
Nonionic surfactant0,1-1,0
Cationic surface-active substance0,1-0,5
Oligopolies2-5



 

Same patents:

FIELD: chemistry.

SUBSTANCE: composition contains (a) a continuous phase composed of a matrix of at least one elastic hydrophobic polymer incompatible with starch, said polymer being selected from the class of polyesters containing carboxylic diacid and diol groups; (b) a homogeneously dispersed starch phase in form of nanoparticles. A film with thickness of 20 mcm obtained from said composition and tested according to ASTM D882 is characterised by a K factor greater than 28 and by arithmetic mean size of the particles of said dispersed starch phase (b) of less than 0.25 mcm. The K factor is calculated using the formula: K=(breaking load)×(Young's modulus)×(breaking energy)/1000000. The invention also relates to a film and textile products made from said biodegradable composition, as well as a bag or sack made from said film and used to carry commodities and pack food products.

EFFECT: biodegradable compositions have a high load, improved modulus, high breaking strength in two directions without any transverse displacement and are particularly advantageous for producing thin films.

48 cl, 3 dwg, 3 tbl, 3 ex

FIELD: chemistry.

SUBSTANCE: invention relates to biodegradable multiphase 5 compositions for making articles, which are characterised by that they contain three phases: (a) a continuous phase consisting of a matrix of at least one elastic hydrophobic polymer which is incompatible with starch; (b) a dispersed starch phase in form of nanoparticles with average size of less than 0.3 mcm, (c) an additional dispersed phase of at least one non-elastic and brittle polymer with 10 modulus of elasticity higher than 1000 MPa.

EFFECT: invention enables to obtain articles with modulus of elasticity higher than 300 MPa and significant isotropy in two, longitudinal and transverse, directions with respect to fracture propagation.

41 cl, 3 tbl, 2 dwg, 2 ex

FIELD: chemistry.

SUBSTANCE: method involves applying a water-based adhesive composition which contains non-gelled starch and additionally 0.1-50 wt % of one or more polymers (P) having an amine group or an amide group onto one or more parts of wood-based material and joining the one or more parts with one or more additional parts of wood-based material.

EFFECT: high quality of gluing.

13 cl, 2 tbl, 5 ex

FIELD: chemistry.

SUBSTANCE: in the present method, biopolymer starting material and a plasticiser are fed into the feeding zone of an extruder having an auger configuration such that the biopolymer starting material, particularly starch, in the extruder undergoes processing by shearing forces, and a cross-linking agent is fed into the extruder on the process scheme downstream the feeding zone. The method is characterised by output higher than or equal to 1.0 metric ton of the product per hour. The biopolymer starting material and plasticiser are preferably fed into the feeding zone separately. The extruder in the feeding zone can have single-turn elements. Temperature in the intermediate section of the extruder is not higher than 100°C. Configuration of the auger can include two or more sealing sections for water vapour. Shearing forces in the first section of the extruder can be greater than shearing forces in the neighbouring second section of the extruder lying on the process scheme downstream the first section. Water can be fed into the post-reaction section lying after the position in which the cross-linking reaction has finished in order to improve operational characteristics of the head.

EFFECT: method enables to obtain cross-linked nanoparticles of a uniform size, having high molecular weight and also enables to manipulate molecular weight of a protective colloid.

38 cl, 3 dwg, 2 tbl, 10 ex

FIELD: chemistry.

SUBSTANCE: invention relates to chemical and food industry, particularly to production of biodegradable plastic materials and can be used to make moulded or film articles for various purposes, including food purposes. The polymer composition for moulding biodegradable articles from molten mass contains polyolefins, biodegradable filler - starch and a process additive, which is a protein phosphatide concentrate (or fuzz) - a by-product of production of unrefined sunflower or rapeseed oil.

EFFECT: obtaining a polymer composition which can decompose under the effect of environmental factors and can be digested by microorganisms, having good biodegradation properties, and also capable of reducing the cost of the product and power consumption during production.

2 dwg, 1 tbl, 3 ex

FIELD: chemistry.

SUBSTANCE: invention relates to chemical and food industry, particularly to production of biodegradable plastic materials and can be used to make moulded or film articles for various purposes, including food purposes. In the method of producing a universal additive which initiates polymer decomposition, exclusively consisting of natural material which includes a matrix, natural polysaccharides, binder, a heat stabiliser and a culture medium, involving mixing said components in a heated mixer at temperature 40-70°C and further granulation or pelletisation of the obtained mixture, the novelty lies in that the matrix contained in the additive is edible paraffin (food additive E905), oxidised polyethylene wax (food additive E914), the natural polysaccharide is starch, the binder is collagen-containing products (gelatin, belkozin, hide glue etc), the heat stabiliser is modified starch THERMTEX and the culture medium is phospholipids.

EFFECT: invention increases biodegradability of the compositions and improves heat stabilisation properties thereof, enables to control the biodegradation duration of the compositions and water-absorption of the material and improves rheological properties of the compositions.

1 tbl, 4 ex

FIELD: food industry.

SUBSTANCE: invention relates to a composition suitable as a substitute of chemically modified starch, to the composition production method, to a beverage and sauce containing the said composition and to the composition application as an additive to food products, fodder products, pharmaceutical or cosmetic products. According to the invention, the composition contains citrus fibres with moisture-binding ability from 7 to 25 g of water per 1 g of fibre and native starch chosen from the group consisting of corn starch, rice flour, sorghum starch, tapioca starch, flour of gold ripeness wheat, potato starch free of amylase and their mixture. The weight ratio of citrus fibres to native starch in the composition is 1:10 - 2:1 with food fibres content in the citrus fibres equal to 60 - 85 wt %.

EFFECT: citrus fibres and native starch in the composition allow to produce a product resistant to shear force, improve the texture and stability in the process of multiple freezing.

14 cl, 1 dwg, 4 ex

FIELD: chemistry.

SUBSTANCE: product contains the following in wt %: 1-50 modified hybrid resin based on natural fatty acids and 99-50 natural material selected from cellulose, wood, wood fibre, flax, hemp, starch and another natural fibre or combinations thereof. The product can contain 20-80 wt % thermoplastic, 30-70 wt % binder or natural adhesive. The hybrid resin is obtained via water-emulsion polymerisation of an acrylate monomer - butylacrylate, methyl methacrylate or butylacrylate, on an alkyde resin based on fatty acids in the presence of a radical initiator at 30-100°C. Fatty acids are selected from tall oil, suberin fatty acids, cutin fatty acids, vegetable oils and mixtures thereof. The composite product is obtained by mixing acrylate hybrid and natural material or combination thereof. Further, the product is moulded and hardened under heat at 120-200°C until a composite product of the given type is obtained.

EFFECT: invention enables to obtain composite plates with improved properties, good biodegradability and low toxicity; such properties of the plates are achieved by using modified hybrid resins in form of a stable aqueous emulsion as binding materials and compatibilisers.

22 cl, 1 tbl, 1 dwg, 9 ex

FIELD: chemistry.

SUBSTANCE: invention relates to composite products, particularly a composite panel containing hybrid resins based on natural acids, as well as a method of producing a composite product. The product contains the following in wt %: 1-50 modified hybrid resin based on natural fatty acids and 99-50 natural material selected from cellulose, wood, wood fibre, flax, hemp, starch and another natural fibre or combinations thereof. The product can optionally contain 20-80 thermoplastics, 30-70 binder or natural adhesive. The hybrid resin is obtained via condensation of a mixture of natural C12-C20 fatty acids modified with maleic acid or anhydride, and an alkyde resin based on fatty acids of tall oil, suberin fatty acids, cutin fatty acids, plant oil or mixtures thereof. Properties of the panel are achieved using modified hybrid resins in form of a stable aqueous emulsion as binding materials and compatibilisers.

EFFECT: invention enables to obtain composite panels with improved properties, specifically good biodegradability and low toxicity.

17 cl, 1 tbl, 27 ex

FIELD: chemistry.

SUBSTANCE: composition is an adhesive composition based on starch or polyvinyl acetate. The adhesive composition contains glue and an additive. The additive is a homopolymer of α,β-unsaturated acrylic acid or a copolymer of α,β-unsaturated acrylic acid with at least one alkylacrylate. The homopolymer or copolymer is cross-linked by a cross-linking agent which is a multifunctional vinylidene monomer. The vinylidene monomer is, for example, butadiene, isoprene, divinyl benzene or divinyl naphthalene. The cross-linking agent is polyalkenyl ether with several ether groups, particularly allyl pentaerythritol. The additive is a pseudoplastic material. The adhesive composition contains at least 0.001 wt % additive. The method of preparing the adhesive composition involves diluting the additive with starch and an optical brightening agent and then adding to the adhesive composition. The additive is mixed in form of a solid composition with a solid starch composition in form of a solid mixture prepared beforehand. The solid mixture contains thickened starch, alkali, powdered starch, borax and 0.001-5 parts additive. Alternatively, the additive is added to a liquid starch composition in form of a liquid composition. The adhesive composition is used particularly to make packed cardboard with several stacked layers of paper or cardboard.

EFFECT: adhesive composition has low viscosity when applied on corrugated cardboard, after which viscosity instantly increases, which prevents the glue from flowing off and ensures good adhesion.

16 cl, 1 dwg

FIELD: chemistry.

SUBSTANCE: group of inventions discloses a polyethylene composition, a method for preparation thereof, articles made therefrom and a method of making said articles. The polyethylene composition contains (1) 100 wt % or less of units derived from ethylene; and (2) less than 15 wt % of units derived from one or more α-olefin comonomers. The polyethylene composition has density of 0.907-0.975 g/cm3, molecular weight distribution (Mw/Mn) of 1.70-3.62, flow melt index (I2) of 2-1000 g/10 min, molecular weight distribution (Mz/Mw) of less than 2.5 and vinyl unsaturation of less than 0.06 vinyl groups per thousand carbon atoms present in the backbone chain of said composition. The method of producing the polyethylene composition includes the following steps: (1) (co)polymerisation of ethylene and at least one or more α-olefin comonomers in the presence of a hafnium-based metallocene catalyst through a gas-phase (co)polymerisation process in a reactor in a single step; and (2) a polyethylene composition is obtained, where the polyethylene composition has parameter values given according to the invention: density, molecular weight distribution (Mw/Mn), flow melt index (I2) and vinyl unsaturation. Articles made by pressure moulding contain the polyethylene composition which contains (1) 100 wt % or less of units derived from ethylene and (2) less than 15 wt % of units derived from one or more α-olefin comonomers. The polyethylene composition has the following parameters: density, molecular weight distribution (Mw/Mn), flow melt index (I2), molecular weight distribution (MZ/Mw) and vinyl unsaturation in accordance with its parameters given above. The method of making pressure moulded articles includes the following steps: (a) selecting a polyethylene composition which contains (1) 100 wt % or less of units derived from ethylene; and (2) less than 15 wt % of units derived from one or more α-olefin comonomers; (b) pressure moulding said polyethylene composition; and (c) the pressure moulded article is then made.

EFFECT: high efficiency of the method.

FIELD: chemistry.

SUBSTANCE: invention relates to fibre made from a polyethylene composition, a method of making said fibre, fabric made from said fibres and a method of making said fabric. The fibre is made from a polyethylene composition which contains at least 80 wt % of a (co)polymer, which contains at most 100 wt % links obtained from ethylene and less than 20 wt % links of one or more α-olefin comonomers. The composition has density of 0.920-0.970 g/cm3, molecular weight distribution (Mw/Mn) of 1.70-3.5, flow melt index (I2) of 0.2-1000 g/10 min, molecular weight distribution (Mz/Mw) of less than 2.5 and vinyl unsaturation level of less than 0.1 vinyl groups per thousand carbon atoms present in the backbone chain of said composition. The disclosed fibre can have denier value per filament less than 50 g/9000 m, breaking strength of 0.1-15 g/denier and relative elongation less than 1500%.

EFFECT: fabric made from said fibre, both woven and nonwoven, have high tearing strength, improved softness and drapeability.

10 cl, 4 dwg, 10 tbl

FIELD: process engineering.

SUBSTANCE: invention relates to tubes intended for transportation of highly abrasive solid particles and sludge, particularly, to ionomer tubes. Tubular or cylindrical article innermost layer that features thickness of about 6.3-102 mm and includes ionomer. Invention covers also methods of tube production and piping of abrasive materials.

EFFECT: longer life, higher wear resistance.

18 cl, 31 tbl, 181 ex

FIELD: chemistry.

SUBSTANCE: multimodal copolymer of ethylene and one or more alpha-olefins contains 4-10 carbon atoms and is characterised by density of 924-935 kg/m3, melt flow index PTR5 of 0.5-6.0 g/10 min, melt flow index PTR2 of 0.1-2.0 g/10 min, and shear thinning index UVS2.7/210 of 2-50. The multimodal ethylene copolymer is obtained in two steps by polymerisation in the presence of a catalyst with a single polymerisation centre of ethylene, hydrogen and one or more alpha-olefins having 4-10 carbon atoms. A low-molecular weight component (A) of the ethylene polymer is obtained in a first polymerisation zone and a high-molecular weight component of the ethylene copolymer (B) is obtained in a second polymerisation zone. The first and second polymerisation steps can be carried out in any order and the next step is carried out in the presence of a polymer obtained at the previous step. Components (A) and (B) are present in the multimodal ethylene copolymer in amount of 30-70 wt % and 70-30 wt %, respectively, of the total amount of components (A) and (B). Component (A) has weight-average molecular weight of 5000-100000 g/mol and density of 945-975 kg/m3, and component (B) has weight-average molecular weight of 100000-1000000 g/mol and density of 890-935 kg/m3.

EFFECT: tubes have good mechanical properties and are suitable for transporting liquids under pressure.

15 cl, 1 tbl, 3 ex

FIELD: chemistry.

SUBSTANCE: multimodal ethylene copolymer has density of 924-960 kg/m3, melt flow index STR5 of 0.5-6.0 g/10 min, melt flow index STR2 of 0.1-2.0 g/10 min and shear thinning index IUVS2.7/210 of 2-50. The multimodal ethylene copolymer contains at most 100 ppm by weight of volatile compounds. The multimodal ethylene copolymer is obtained in two steps by polymerisation in the presence of a catalyst with a single polymerisation centre of ethylene, hydrogen and one or more alpha-olefin having 4-10 carbon atoms. A low-molecular weight component (A) of the ethylene polymer is obtained in a first polymerisation zone and a high-molecular weight component of the ethylene copolymer (B) is obtained in a second polymerisation zone. The first and second polymerisation steps can be carried out in any order and the next step is carried out in the presence of a polymer obtained at the previous step. Components (A) and (B) are present in the multimodal ethylene copolymer in amount of 30-70 wt % and 70-30 wt %, respectively, of the total amount of components (A) and (B). Component (A) has weight-average molecular weight of 5000-100000 g/mol and density of 945-975 kg/m3, and component (B) has weight-average molecular weight of 100000-1000000 g/mol and density of 890-935 kg/m3.

EFFECT: improved properties of the compound.

15 cl, 1 tbl, 3 ex

FIELD: chemistry.

SUBSTANCE: invention relates to the technology of producing a stabilised composition based on low-pressure polyethylene which is meant for blow moulding and pressure casting articles. The method is realised by mixing, in a molten mixture, polyethylenes of different density and additives. The mixture of polyethylenes, taken in granular form, comprises high-density polyethylene and low-density linear polyethylene or high-density polyethylene and medium-density linear polyethylene. The additives are added the composition in form of an additive based on low-density linear polyethylene, which is obtained from a molten granular polymer concentrate. The additive contains a phenol antioxidant which is a sterically hindered phenol, and an ethylene and vinyl acetate copolymer which contains 9-16 wt % vinyl acetate, with the weight ratio of the low-density linear polyethylene to the ethylene and vinyl acetate copolymer ranging from 0.8:1 to 4.3:1. Content of the ethylene and vinyl acetate copolymer in the composition ranges from 0.5 to 1.5 wt % and content of the phenol antioxidant ranges from 0.05 to 0.15 wt %.

EFFECT: stabilised compositions obtained using the disclosed method have an optimum set of physical and mechanical properties and high cracking resistance.

4 tbl, 22 ex

FIELD: chemistry.

SUBSTANCE: copolymer of ethylene and a (C3-C18) α-olefin comonomer has density of 0.900-0.940 g/cm3, falling dart impact strength (F) satisfying the correlation with Vicat softening point as expressed by formulae (1) and (2), where V is Vicat softening point measured according to ASTM D 1525; and F is falling dart impact strength. The ethylene copolymer having improved impact properties is applicable to film, injection, compound, sheet, rotational, pipe or blow moulding.

EFFECT: producing ethylene copolymers having excellent processability and high impact strength owing to high rigidity.

13 cl, 4 dwg, 3 tbl, 14 ex

FIELD: chemistry.

SUBSTANCE: multimodal copolymer of ethylene and one or more alpha-olefins containing 4-10 carbon atoms is characterised by density of 937-950 kg/m3, flow melt index STR5 of 0.5-2.0 g/10 min, flow melt index STR2 of 0.2-1.0 g/10 min, and shear thinning index IUVS2.7/210 of 0.3-20. The multimodal copolymer contains 30-70 wt % low-molecular weight ethylene polymer, selected from an ethylene homopolymer and a copolymer of ethylene and one or more alpha-olefins containing 4-10 carbon atoms, and is characterised by weight-average molecular weight of 5000-100000 g/mol and density of 960-977 kg/m3, and 30-70 wt % copolymer of high-molecular weight ethylene and one or more alpha-olefins containing 4-10 carbon atoms, and is characterised by average molecular weight of 100000-1000000 g/mol and density of 890-929 kg/m3.

EFFECT: compositions are flexible; tubes made therefrom can be easily bent or coiled into a ring; the tubes are characterised by sufficient mechanical strength, which enables their use under pressure.

15 cl, 1 dwg, 3 tbl, 5 ex

FIELD: chemistry.

SUBSTANCE: group of inventions relates to a high-density polyethylene-based bimodal composition and a method of producing said composition, as well as a bottle cap made from said composition, and a method of making said cap. The composition contains a first component which is a high-molecular weight ethylene/alpha-olefin copolymer having density ranging from 0.920 to 0.946 g/cm3 and flow melt index (I21.6) ranging from 1 to 15 g/10 min. The composition also contains a second component which is a low-molecular weight ethylene polymer, having density ranging from 0.965 to 0.980 g/cm3 and flow melt index (I2) ranging from 30 to 1500 g/10 min. The obtained composition has flow melt index (I2) of at least 2 g/10 min, density ranging from 0.950 to 0.960 g/cm3 and molecular weight distribution ranging from 5 to 11. The method of producing the composition involves a step of feeding an ethylene and alpha-olefin comonomer into a first reactor and polymerisation of the ethylene and alpha-olefin comonomer in the first reactor to obtain a first component which is a high-molecular weight ethylene/alpha-olefin copolymer. The first component and additional ethylene are then fed into a second reactor and the additional ethylene is polymerised in the second reactor to obtain a second component which is a low-molecular weight ethylene polymer. The high-density polyethylene-based composition is then obtained.

EFFECT: high crack resistance and impact strength of articles made from the obtained composition.

13 cl, 7 dwg, 4 tbl, 6 ex

FIELD: chemistry.

SUBSTANCE: composition contains a polyolefin polymer matrix containing a propylene homopolymer with MWD (molecular weight distribution) of 1.5-5.0 and copolymer of ethylene with one or more comonomers selected from alpha-olefins with 4-12 carbon atoms, having density of not more than 920 kg/m3. The weight ratio of the propylene homopolymer to the copolymer of ethylene in the polyolefin polymer matrix ranges from 95:5 to 60:40. The propylene homopolymer is polymerised in the presence of a catalyst with a single cross-linking point, where the cold xylene-soluble fraction is not more than 2 wt %. The disclosed composition has good mechanical properties, particularly impact resistance at low temperatures and bending properties, without the need to use special equipment to prepare the mixture and/or additives when producing said compositions.

EFFECT: articles made from the composition have good scratch resistance along with low lustre.

14 cl, 3 tbl, 10 ex

FIELD: chemistry.

SUBSTANCE: present invention relates to a composition for moulding articles and a method of producing said composition. The composition contains 100 pts.wt of a polymer component A, which consists of 5-100 wt % of a lactic acid polymer (component A-α) and 95-0 wt % of thermoplastic resin (component A-β), 0.001-5 of pts.wt of a phosphoric-fatty acid ester (component B), 0.01-5 pts.wt of metal phosphate salt (component C), 0.001-2 pts.wt of at least one antioxidant (component D), 0.001-10 pts.wt of a chain end closing agent (component E) and 0.01-0.3 pts.wt of hydrotalcite. The antioxidant is selected from a group comprising a phosphite-based compound, phosphonite-based compounds, a hindered phenol-based compound and a thioether-based compound. The method of producing the composition involves mixing, at 250-300°C, composition-1, which contains poly-1-lactic acid and a phosphoric-fatty acid ester, and composition-2, which contains poly-d-lactic acid and a phosphoric-fatty acid ester, in the presence of a metal phosphate salt to obtain a stereo-complex lactic acid polymer. Further, component A, which consists of the obtained stereo-complex polymer and a thermoplastic resin, is mixed with the antioxidant and the chain end closing agent.

EFFECT: obtained composition has good thermal stability, especially in humid conditions.

14 cl, 22 tbl, 70 ex

Up!