SU883097A1 - Method of producing polymeric composition - Google Patents

Description

The invention relates to methods for processing polymers and can be used in the manufacture of polymer compositions. A method of obtaining a polymer composition by shear deformation under high pressure of a mixture of polyethylene and deuterated polyethylene is known. However, this method requires high pressure processing mixture. The closest to the proposed technical solution according to the technical essence and the achieved effect is a method of obtaining a polymer composition by mixing two polymer components (polypropylene with polyethylene) with subsequent shear deformation. C J The disadvantage of this method is the large value of pressure J used at which compatibility of polymers is achieved . A combination of polyethylene and polypropylene is observed at a pressure of 20 kbar. The purpose of the invention is to reduce the pressure. This goal is achieved in that according to the method for producing a polymer composition by mixing polypropylene with another polyolefin followed by shear deformation under pressure, polyethylene or a copolymer of ethylene with propylene is used as a polyolefin and an inorganic filler selected from the group containing carbon black is used at the mixing stage , Aerosil and asbestos, particle size of 0.005-2 microns in the amount of 0.530 wt.%. The compatibility of a mixture of two or more amorphous or amorphous polymers is characterized by the presence of a single relaxation transition in this mixture in the region of the glass transition temperature, i.e. uniform temperature.

glass transition. Non-uniform, incomparable mixture of polymers has several glass transition temperatures, respectively. the amount of polymer components in the mixture. The glass transition temperatures of the polymer components in the initial mixture, as well as in the mixture, subjected to the action of shear deformation (DM) under high pressure (HP), are determined from the position of the maximum relaxation on the radio thermoluminescence (RTL) luminescence curves.

FIG. 1-4 shows the graphs of radio thermoluminescence.

For example, Polypropylene (PP) in an amount of 1.60 g is mixed with 40 g of synthetic ethylene-propylene rubber (EPDM) in a laboratory extruder at and then granulated. Films with a thickness of 100 microns are prepared from the granules by hot pressing. Then samples of 20–30 mm in diameter are cut from the films, placed between two Bridgman anvils located in the press, and pressurized to 5–10 ppm. The shear deformation (DM) under high pressure (HP) is carried out by turning one of the anvils. In this case, the rotation angle was 1,000 degrees, i.e. the movable anvil in total made 2.78 turns around its axis. The treatment of ADHD is carried out at room temperature

The initial mixture of W / SKEP, which is not subjected to the action of ADHD (Fig. 1, curve I), has two maxima on the RTL curve at temperatures of 68 and corresponding to the glass transition temperature (Tc) of the SEC and PP. In a mixture of PP / EPDM, subjected to the action of DM at a pressure of 10 kbar, Tc PP and EPDM gradually approach each other (Fig, 1, curve 2). Diabetes at a pressure of 20 kbar leads to the formation of a quasi-homogeneous composition. Tc which corresponds. However, this composition has another weakly pronounced relaxation transition in the region of -61 ° Ct, which is associated with the presence of the free EPDM phase (Fig. 1, curve 3) Warming up for 5 min of the PP / EPDM composition subjected to the action of DM at 10 and 20 kbar leads to its phase separation, and the PTL curve in this case becomes the same as the initial mixture curve (Fig. 1, curve 1.)

PRI mme R 2. Mix PP with EPDM in quantities of 160 and 40 g, respectively, with additive I and 10 g of aerosil with a particle size of 0.005-0.04 microns, and the treatment is carried out as in Example 1. Then the samples are subjected to DM at a pressure 5 and 10 kbar, as in example 1.

With the introduction of the active inorganic filler - Aerosil in a mixture of PP / EPDM in the amount of 0.5 wt.%, The pressure at which the formation of a quasihomogeneous composition is observed, has reached 10 kbar (Fig. 2, curve 1)

An increase in the content of aerosil to 5 wt.% In the mixture leads to a decrease in the pressure at which such a quasi-homogeneous composition is formed, to 5 kbar. If this mixture is subjected to diabetes at a pressure of 10 kbar, a homogeneous PP / EPDM composition is formed, having a single TC at -25 ° C (Fig. 2, curve 2). Remelting such compositions at 240 ° C does not lead to their complete phase separation, and the RTL curves remain the same as before remelting (Lig. 2, curves 1 and 2).

The same as in Example 2, changes in Tc are observed when 20% by weight of carbon black with a particle size of 0.2 to 1 µm and asbestos with a particle size of O, 5-2, O-µm are introduced into the PP / EPDM mixture. . However, the content of carbon black in the mixture to obtain a homogeneous non-layering composition with a single Tc should

be increased to 20-30% by weight of the total polymer components. This is due to some aggregation of particulate, carbon black, as a result of which their size increases to 2 microns, and

these coarse particles do not participate in the process of desparing polymer components under the action of shear deformations at high pressures. Asbestos content in the mixture

to obtain a homogeneous PP / EPDM composition, it should also be 1020 wt.% based on the weight of the polymer components. This is due to the presence of asbestos particles in the mixture.

2 microns. FIG. Figure 3 shows the PTL curves of PP / EPDM compositions with 30 wt.% Cac (curve 1) and 15 wt.% Asbestos (curve 2) subjected to DM of 1000 at pressures of 5 and 10 kbar, respectively.

EXAMPLE 3. PPs are mixed with EPDM, as in Example 1, and an inactive inorganic filler — titanium dioxide with a particle size of 2–10 µm in an amount of 10 wt.% Is added to the mixture at the mixing stage. Processing such a mixture in a press with a DM of 1000 and a pressure of 10 kbar did not lead to the convergence of glass transition temperatures (Fig. A, curve 1).

Thus, the introduction into the polymer mixture of active inorganic fillers, such as aerosil black or asbestos. particle size from 0.005 to 2 microns in amounts from 0.5 to 30 wt.% of the total weight of the polymer components, allows a significant reduction in pressure by 2-4 times, at which, as a result of shear deformation, the amorphous regions of the polymers on the molecules (segmental) level and a thermally stable polymer composition is formed, having a single glass transition temperature.

The proposed method for the preparation of polymer compositions allows the preparation of new types of polymers and composite polymeric materials. and can be used in industrial applications, since pressures up to 10 kbar are currently achievable on industrial equipment used in metal processing.

Claims (1)

Invention Formula A method for producing a polymer composition by mixing polypropylene with another polyolefin followed by shear deformation under pressure, is widely used because, in order to reduce pressure, polyethylene or ethylene-propylene copolymer is used as a polyethylene or propylene copolymer to introduce an inorganic filler selected from the group including carbon black, aerosil and asbestos, particle size of 0.005-2 microns in the amount of 0.5-30 wt.%. Sources of information taken into account during the examination 1. V. Zhorin. et al. Behavior of mixtures of polyethylene and deuterated polyethylene at high pressures in combination with shear deformations. Reports of the Academy of Sciences of the USSR, 1977, Vol. 232, K 1, p. 118. 2, Zhorin V.A. et al. The study of mixtures of polyethylene and polypropylene after exposure to high pressures. Reports of the Academy of Sciences of the USSR, 1979, vol. 244, IPS, p. 1153-1156. ct u 9 80 -W of Fig. 1 -W -80 FIG. 2 ("H 0 C -w Pvi.S -60 -0 C 0 FIG.