SU472949A1 - Polymer composition - Google Patents

Description

The invention relates to the stabilization of polymeric materials.

A stabilized polyethylene composition based on polyethylene is known, in which zinc diisopropyl dithiophosphate (zinc DDF) is used as a stabilizing additive.

In order to increase the stabilization effect, it is proposed to use a mixture of zinc DDF with bis (2,4-dioxyphenyl) disulfide in a molar ratio of 1: 2–2: 1 in an amount of 0.1–2 wt. % The proposed mixture of compounds is a more effective thermostabilizer of polyolefins (high and low density polyethylene and polypropylene) as compared to the Santonox used in the industry, as well as zinc DDF.

The effectiveness of these additives is investigated on powdered high-density polyethylene of grade P-4020, on granular low-density polyethylene of mark 10702-020, and on powdered isotactic polypropylene. The stabilizer (0.3 wt.%) Is introduced into high-density polyethylene and polypropylene in the form of an acetone solution, after which the solvent is removed by drying in a vacuum oven. A stabilizer is introduced into low density polyethylene on rollers. J obtained compositions are made

films on a hydraulic press with heating plates. 50 mg of polymer are cut out from the middle part of the film and placed in an oxidizing unit. The stabilizing effect of antioxidants is assessed at 160 ° C and oxygen pressure of 760 mm Hg. Art. The results of the experiments are given in table. one

Table 1

From tab. 1 that the mixture of zinc DDF and bis- (2,4-dioxyphenyl) -disulphide is significantly and ideally superior in inhibiting efficacy under the same conditions to known inhibitors.

In addition to the determination of the neurode of the induction of oxidation, the inhibitory effect of these additives is evaluated by the thermomechanical degradation of polyethylene on the rollers and 160 C.

within 12 hours Made of polyethylene rollers made of polyethylene and of high DENSITY, rolls of 0.2–0.3 mm thickness are made. Samples are cut out of the films in a double-sided and x-blade spatula, mechanical tests are carried out in accordance with the requirements of GOST 270-G4 on an RLS-60 tensile testing machine. Res) lt1 islsti in the table. 2

table 2