RU584519C - Polymeric composition - Google Patents

Description

The invention relates to the field of plastic waste processing and can be used in the recycling of partially oxidized polyethylene waste.

Currently, the amount of plastic waste is increasing rapidly, so the problem of reuse arises.

It is known that the waste of thermoplastic materials, including polyethylene, is processed directly into granules.

However, the resulting product has low fluidity and physico-mechanical properties, which leads to a small productivity of processing equipment, poor quality of molded products, frequent tearing of extruded strands in the production of granules, films, and blow products.

Closest to the present invention is a composition comprising polyethylene and synthetic rubber.

The addition of rubber, increasing the low temperature characteristics of polyethylene, generally does not alter the physicomechanical properties of the composition.

To improve the physicomechanical properties and reduce the cost of the composition, the proposed polymer composition contains oxidized polyethylene as polyethylene; saponification number of 15-150 mg equiv / g in the following ratio, May. %:

Oxidized Polyethylene94-96

Synthetic rubber .4-6

As oxidized polyethylene can be used obsolete products made of polyethylene (films for covering greenhouses, bags, under fertilizers, cultural and household products, etc.), containing hydroxyl, carboxyl, carbonyl and complex ether groups and characterized by the indicated saponification number.

As synthetic rubbers, the composition contains general purpose rubbers, such as, for example, polybutadiene or divinyl styrene rubber.

The composition may also contain crystallization nucleating agents, for example aerosil, which increase the speed of thermoforming and strength of the obtained products,

P r and m er. A partially oxidized worn polyethylene film used to cover greenhouses and having a saponification number of 15-150 meq / g; crushed in a rotary grinder to a size

particles of 1-7 mm are passed through a rotary washer, squeezed on a rotary squeezer, dried in a vortex dryer, and crushed raw materials are averaged in a bunner-homogenizer. Thus prepared polyethylene waste having a flow rate of 0.1 t / 10 min, is fed into the extruder. It also serves synthetic rubber in crushed form (particle size

5 1-3 mm).

The properties of the resulting compositions in comparison with the known are given in table / l. . . . 0 With the introduction of synthetic rubbers to

partially oxidized waste of polyethylene there is an unexpected improvement in the quality and physico-mechanical properties of secondary polyethylene: relative

5, elongation at break increases 1.2-1.4 times, melt flow rate 3-3.5 times, cracking resistance more than 35 times, frost resistance 2 times. At the same time, with the introduction of rubbers

0 in polyethylene, such an improvement in quality and its physical and mechanical properties is not observed.

. Obtaining secondary polyethylene from partially oxidized is very important in

5 at present, since the waste resources from lumpy and film polyethylene are 350-4QO thousand tons per year. The development of these resources is equivalent to the creation of seven primary polyethylene productions with a capital investment of about 300 million rubles. In addition to these advantages, the processing of partially oxidized polyethylene is of great importance in protecting the environment, since

5 Nowadays, in large quantities, polyethylene products and agricultural films are sent in huge quantities to landfills, burned, and buried in the ground.

(56) Patent of England No. 1371518, cl. 03 R, published. 1974.

Plastics. 1974, No. 8, p. 5860.

. Physico-mechanical properties of the composition