Crystalline polythiocarbonate and preparation method therefor

A preparation method of a crystalline polythiocarbonate, comprising:

• co-mixing carbon disulfide, ethylene oxide, an initiator, and a Lewis acid in a reactor, and carrying out a native or solution copolymerization reaction at 0-150° C. under autogenous pressure;
• wherein the crystalline polythiocarbonate is a random copolymer and comprises five structural units L1 to L5 as shown in the following formula:
• the structural unit L1 has a molar content of 10-80%, the structural unit L2 has a molar content of 10-80%, the structural unit L3 has a molar content greater than 0% and less than 15%, the structural unit L4 has a molar content greater than 0% and less than 10%, and the structural unit L5 has a molar content greater than 0% and less than or equal to 10%;
• the crystalline polythiocarbonate has a crystallinity of 1-78% and a melting temperature of 117-245° C.

A preparation method of a crystalline polythiocarbonate, comprising:

• co-mixing an initiator, a Lewis acid, and a third monomer in a reactor and carrying out a native or solution copolymerization reaction at 0-150° C. under autogenous pressure, to obtain a polyether intermediate or a polyester intermediate with a target molecular weight;
• and
• co-mixing the polyether intermediate or the polyester intermediate with the target molecular weight with carbon disulfide and ethylene oxide in the reactor, carrying out a second stage reaction in a native or solution at 0-150° C. under autogenous pressure, and obtaining a final product by post-processing;
• wherein the crystalline polythiocarbonate is a random copolymer and comprises five structural units L1 to L5 as shown in the following formula:
• the structural unit L1 has a molar content of 10-80%, the structural unit L2 has a molar content of 10-80%, the structural unit L3 has a molar content greater than 0% and less than 15%, the structural unit L4 has a molar content greater than 0% and less than 10%, and the structural unit L5 has a molar content greater than 0% and less than or equal to 10%;
• the crystalline polythiocarbonate has a crystallinity of 1-78% and a melting temperature of 117-245° C.;
• the molecular chain segments of the crystallizable polythiocarbonate further comprises, a polyether or a polyester link derived from a copolymerization of the third monomer;
• the third monomer is selected from at least one of:
• an epoxy compound, a cyclic anhydride, and a cyclic lactone.