RU1775426C - Polymeric composition - Google Patents

Abstract

Usage: the manufacture of dielectrics. SUMMARY OF THE INVENTION: the composition contains, by weight, by weight: a copolymer of styrene with acrylonitrile and methyl methacrylate 80-85, polypropylene or acrylonitrile butadiene styrene copolymer 10-15; butadiene-styrene thermoplastic elastomer of radial structure with a content of bound styrene of 30% 5-15. 2 tab.

Description

The invention relates to the processing of plastics, and more particularly to polymeric materials having improved physical, mechanical and dielectric properties, which are used in the electrical and radio engineering industries.

When casting products on a twin-screw machine, two different polymers are often used. The waste generated during this process (sprues, scraps, defective products, etc.) cannot either be divided into two polymers if they are the same color or their separation requires a lot of manual labor. A mixture of polymers is not always possible to use because of their incompatibility, and therefore waste disposal is often carried out by incineration or disposal, which is economically disadvantageous.

The most appropriate is the processing of industrial polymer waste into products for various purposes.

Known compositions comprising waste thermoplastics and a modifying additive.

However, the use of a tri-substituted sodium phosphate modifier for acrylate mixtures does not improve the strength properties of the compositions.

The closest in technical essence and the achieved result is a polystyrene polymer composition based on polystyrene of high-impact secondary grade B (TU6-19-153-80), obtained on the basis of a mixture of wastes of various grades of high-impact polystyrenes.

A disadvantage of the known polymer mixture is its low specific impact strength and strength.

The aim of the invention is to increase the strength properties.

The goal is achieved in that the polymer composition based on waste thermoplastics as waste thermoplastics contains a copolymer of styrene with acrylonitrile and methyl methacrylate (MCH) 85-80 and polypropylene or acrylonitrile butadiene styrene copolymer composition (ABS plastic), and also

Yo

Vj h |

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4 Yu O

butadiene-styrene thermoplastic elastomer of a radial structure with a content of bound styrene of 30%

A b

AB-X-VA B A

where A is a polystyrene block; B is a block of polybutadiene; X is the remainder of the combining agent - silicon halide or divinylbenzene, in the following ratio of components, parts by weight:

A styrene copolymer with acrylonitrile and

methyl methacrylate 80-85

Polypropylene or Acrylonitrile Butadiene-Styrene Copolymer 10-15

Thermoelastoplast 5-15

Example 1. A granular secondary impact-resistant polystyrene grade B (TU 6-19-153-80) is introduced into an extruder hopper equipped with a mixing device.

Processing mode: Melt temperature, ° С 170-200 Specific pressure, MPa100-120

Form temperature, ° С50-70

Time under pressure, s20-30

Cooling time, s30-60

Test samples are made according to GOST 12019-66 by injection molding. Samples are tested according to standard methods, the properties are shown in the table.

Examples 2-13. Wastes pre-shredded and cleaned from dirt are introduced into the extruder hopper, equipped with a mixing device, which is a mixture of a styrene-methyl methacrylate / acrylonitrile copolymer (MCH) and polypropylene, as well as granular branched DST-ZOR thermoelastoplast. The homogenization of the mixture in the melt and granulation is carried out at an extruder temperature in the zones: 170-190-200-220 ° C.

Test samples are made according to GOST 12019-66 by injection molding.

The composition of the compositions are given in table 1.

Examples 14-25. Compositions are prepared analogously to Examples 2-13. Instead of polypropylene waste, waste of acryl-butadiene styrene plastic (ABS) is used.

The results of the evaluation of the operational properties of compositions based on a mixture of styrene copolymer wastes, a mixture of styrene copolymer and polypropylene show that the modification of these wastes during co-extrusion with a branched thermoplastic elastomer containing 30 wt.% Bonded styrene allows

eliminate delamination and obtain materials with significantly improved molding properties, with lower internal stresses and greater stability of the shape and size of products

The proposed compositions according to examples 5,12,17,24 have a sufficiently high specific impact strength at the level of the prototype and a much higher tensile strength of 23-26 MPa. By varying the content of the components, it is possible to create compositions with certain properties. An analysis of the results shows that the use of the amount of thermoplastic elastomer is more than 15 parts by weight. impractical

because it is not economically profitable and does not lead to an improvement in the properties of the composition (examples 7,13,19 and 25).

The use of styrene butadiene thermoplastic elastomer less than 5 wt.h. (examples

Claims (1)

3,9,15 and 21) does not give the effect of modification. SUMMARY OF THE INVENTION A polymer composition containing a mixture of waste thermoplastics, characterized in that, in order to increase strength of properties, it contains styrene-acrylonitrile and methyl methacrylate copolymer and polypropylene or acrylonitrile-butadiene-styrene copolymer as a waste of thermoplastics, as well as an additional radial butadiene-styrene thermoplastic elastomer with 30% styrene bonded content: A B A-B-X-B-A, B A where A is a polystyrene block, B is a block of polybutadiene; X is the remainder of the coupling agent-silicon halide or divinylbenzene, in the following ratio of components, parts by weight: Styrene copolymer with acrylonitrile and methyl methacrylate 80-85 Polypropylene or Acrylonitrile Butadiene-Styrene Copolymer 10-15 Specified butadiene-styrene thermo-elastoplast Table 2