SU367115A1 - METHOD OF OBTAINING BLOXOPOLYMERS - Google Patents

Description

one

The invention relates to a process for the preparation of block copolymers - polyallomers.

These polymers are used in various fields of technology due to their valuable physicomechanical properties. To improve the properties of polypropylene, such as frost resistance, heat resistance, mechanical characteristics and the like, lolyallomers based on propylene and other α-olefins (ethylene, butene-1, isobutylene, 4-methylpentene-1 and others) are obtained with their sequential. polymerization.

In order to impart increased frost and heat resistance to polypropylene in combination with increased impact resistance, a method of producing propylene-based block copolymers is proposed, which involves the use of vinylcycloalkanes as comonomers. The sequential polymerization of propylene with vinylcycloalkanes is carried out in the medium of propane, an aliphatic or cyclic hydrocarbon solvent, paraffin fractions of kerosene and gasoline at a temperature of 28-80 ° C (preferably 30-50 ° C) and a pressure of 1-40 at. Compounds based on salts of transition metals of the IV-VHI groups of the periodic system and organic compounds of metals I-P1 of the groups of the periodic system of elements are used as catalysts. First, the polymerization of propylene is carried out to a triple degree of conversion, then the unreacted propylene is blown off and a certain amount of vinylcycloalkane is introduced into the reaction mixture and continued

polymerization. When propane is used as a solvent for polymerization, propane-propylene and propane-vinylcycloalkane mixtures are used, and the reaction is carried out at a pressure of 10-40 (preferably 15-

20) ATI. When using other inert organic solvents, pure monomers are used and the polymerization is carried out at 1-40 (preferably 1-20) at. The copolymerization is terminated by feeding isopropyl alcohol into the reaction medium. Washed from catalyst residues and vacuum-dried block copolymers, compared with polypropylene obtained under similar conditions, have increased frost resistance, heat resistance, specific toughness and, as a rule, greater elongation (see table). The resulting copolymers - polyallomers can be used for the production of products with increased impact resistance at low temperatures, as well as dielectrics, fiber and film forming, their materials with high heat and cold resistance. Example 1. In a 1 liter autoclave,

equipped with an electromagnetic stirrer and

jacket, drained under vacuum for 1 hour and purged with dry purified argon or propane, load 300 g of condensed propane-propylene mixture (monomer content is 80 wt.%) without moisture and oxygen access. The temperature in the reactor is increased before and the catalytic-complex consisting of 4.06 g of TiCls (b-form of aluminothermic reduction, STiCls Aids) and 6.8 g of 98% A1 (C2H5) 2C1 are fed. The initial pressure is 12 ati. The polymerization of propylene is carried out while moving for 30 minutes and at a temperature of 40 ° C. The reaction is monitored by pressure drop and chromatographic. After 30 minutes, unreacted propylene is dropped from the reactor along with propane, the autoclave is blown with propane, and then charged 180 g of condensed propane and 48 g of vinylcyclohexane. The reaction of polymerization of vinylcyclohexane on live macroplate x of polypropylene is carried out for 2 hours at a temperature of 40 ° C. After propane is blown, 50 ml of isopropyl alcohol are then introduced into the autoclave. The suspension is discharged from the autoclave, filtered, washed from the catalyst residues and dried to constant weight at a temperature of 80 ° C and a residual pressure of 1 mm Hg. Art.

The output of loliallomer is 114 g, Vicat heat resistance is 107 ° C, cold resistance is -30 ° C, specific impact viscosity is 7.24 kgcm / cm. For polypropylene produced under similar conditions, the corresponding figures are: 92 ° C, –15 ° C and 5.73 kgcm / cm.

Example 2. The polymerization of propylene was carried out as in Example 1 for 120 minutes at a temperature of 30 ° C in the presence of a catalytic complex consisting of 4 g of TiCls and 8 g of Al (C2H5) 2C1. The stage of polymerization of vinyl diclohexane on live polypropylene macrochip x is carried out for 3 hours at a temperature of 30 ° C. The output of polyallomer is 203 g, Vic heat resistance is 106 ° C, cold resistance is -32 ° C, specific impact viscosity is 14.7 kgcm / cm.

Physicomechanical properties of some

propylene block copolymerB

and vinyl cycloalkanes

Subject invention

The method of producing block copolymers by sequential polymerization of propylene and vinyl monomers in an inert hydrocarbon solvent using a catalyst consisting of group IV-VIII transition metal compounds and organometallic compounds of metals I-III, in order to increase the impact resistance at low temperatures and heat resistance of the final products, vinylcycloalkanes are used as vinyl monomers, for example, vin lcyclohexane.