The present invention provides a method for preparing a polycarbonate by removing a solvent from a polycarbonate polymerization solution without impairing the physical properties of the polycarbonate.

An object of this invention is to find a method for introducing a functional group into an aliphatic polycarbonate without impairing the excellent thermal decomposition property of the aliphatic polycarbonate. An aliphatic polycarbonate comprising a constituent unit represented by formula (1): ##STR00001##
wherein R.sup.1, R.sup.2, and R.sup.3 are identical or different, and each represents a hydrogen atom, a C.sub.1-10 alkyl group optionally substituted with one or more substituents, or a C.sub.6-20 aryl group optionally substituted with one or more substituents, wherein two groups from among R.sup.1 to R.sup.3, taken together with the carbon atom or carbon atoms to which these groups are attached, may form a substituted or unsubstituted, saturated or unsaturated 3- to 10-membered aliphatic ring; and X represents a divalent group containing one or more heteroatoms or an alkylene group having 3 or more carbon atoms, and
a constituent unit represented by formula (2): ##STR00002##
wherein R.sup.4, R.sup.5, R.sup.6, and R.sup.7 are identical or different, and each represents a hydrogen atom, a C.sub.1-10 alkyl group optionally substituted with one or more substituents, or a C.sub.6-20 aryl group optionally substituted with one or more substituents, wherein two groups from among R.sup.4 to R.sup.7, taken together with the carbon atom or carbon atoms to which these groups are attached, may form a substituted or unsubstituted, saturated or unsaturated 3- to 10-membered aliphatic ring, the content of the constituent unit represented by formula (1) being 0.1 mol % or more and 1.5 mol % or less, based on the total amount of the constituent units of formula (1) and formula (2).

An object of this invention is to find a method for introducing a functional group into an aliphatic polycarbonate without impairing the excellent thermal decomposition property of the aliphatic polycarbonate. An aliphatic polycarbonate comprising a constituent unit represented by formula (1): ##STR00001##
wherein R.sup.1, R.sup.2, and R.sup.3 are identical or different, and each represents a hydrogen atom, a C.sub.1-10 alkyl group optionally substituted with one or more substituents, or a C.sub.6-20 aryl group optionally substituted with one or more substituents, wherein two groups from among R.sup.1 to R.sup.3, taken together with the carbon atom or carbon atoms to which these groups are attached, may form a substituted or unsubstituted, saturated or unsaturated 3- to 10-membered aliphatic ring; and X represents a divalent group containing one or more heteroatoms or an alkylene group having 3 or more carbon atoms, and
a constituent unit represented by formula (2): ##STR00002##
wherein R.sup.4, R.sup.5, R.sup.6, and R.sup.7 are identical or different, and each represents a hydrogen atom, a C.sub.1-10 alkyl group optionally substituted with one or more substituents, or a C.sub.6-20 aryl group optionally substituted with one or more substituents, wherein two groups from among R.sup.4 to R.sup.7, taken together with the carbon atom or carbon atoms to which these groups are attached, may form a substituted or unsubstituted, saturated or unsaturated 3- to 10-membered aliphatic ring, the content of the constituent unit represented by formula (1) being 0.1 mol % or more and 1.5 mol % or less, based on the total amount of the constituent units of formula (1) and formula (2).

The present disclosure relates to polythioaminals with applications as carriers or delivery vehicles for therapeutic agents or other small molecule cargo. Polythioaminal block copolymer coupled to a therapeutic agent is a polymer-therapeutic conjugate that exhibits higher stability and longer life time in aqueous environments. The polythioaminal block copolymer coupled to a therapeutic agent can be synthesized by reacting hexahydrotriazines with a hydrophobic block precursor, a hydrophilic block precursor, a particle stabilizing segment precursor, and a cargo, such as a therapeutic agent, in a one pot synthesis. The ease of synthesizing the resulting polythioaminal block copolymer coupled to the therapeutic agent while offering the extended stability and polymer life time in aqueous environments make the polythioaminal block copolymer particularly attractive for therapeutic carriers.

A method for preparing granular polycarbonate particles is disclosed herein. In some embodiments, a method for preparing granulated polycarbonate particles includes mixing a polymerization reaction solution comprising polycarbonate and an organic solvent, and an anti-solvent solution comprising water and an anti-solvent to prepare a mixed solution, heating the mixed solution to remove the organic solvent, and drying or filtering the mixed solution to obtain granular polycarbonate particles. The granular polycarbonate particles having excellent physical properties without using a stabilizer or a surfactant can be obtain.

A method for preparing granular polycarbonate particles is disclosed herein. In some embodiments, a method for preparing granulated polycarbonate particles includes mixing a polymerization reaction solution comprising polycarbonate and an organic solvent, and an anti-solvent solution comprising water and an anti-solvent to prepare a mixed solution, heating the mixed solution to remove the organic solvent, and drying or filtering the mixed solution to obtain granular polycarbonate particles. The granular polycarbonate particles having excellent physical properties without using a stabilizer or a surfactant can be obtain.

In an embodiment, a method for making a thermoplastic composition, comprising: melt polymerizing a polycarbonate, extruding and melt filtering the polycarbonate to form a melt filtered polycarbonate; forming the thermoplastic composition comprising the melt filtered polycarbonate, 0.03 to 0.05 wt % of a triacylglyceride release agent; and 0.10 to 0.14 wt % of a UV stabilizer; wherein the weight percentages are based on the total weight of the composition; and extruding the thermoplastic composition.

The present disclosure relates to an economical method of preparing a resin composition including a polyalkylene carbonate with improved thermal stability and processability. More specifically, the method of preparing a resin composition includes the steps of polymerizing carbon dioxide and an epoxide compound in the presence of a zinc-based catalyst and a solvent, recovering monomers, removing the catalyst and recovering raw materials, solution-blending with a thermostable resin to improve the thermal stability and processability, and removing the solvent and byproducts from the reaction mixture by using an agitated flash drum and an extrusion or kneader-type devolatilizer.

The present disclosure relates to a method for separating an organozinc catalyst from a polyalkylene carbonate polymerization solution, and the method of the present disclosure includes: stirring and aging a polymerization solution including a polyalkylene carbonate resin, an organozinc catalyst, an alkylene oxide and a polymerization solvent; and filtering the polymerization solution after completing the aging.

The present disclosure relates to a method for separating an organozinc catalyst from a polyalkylene carbonate polymerization solution, and the method of the present disclosure includes: stirring and aging a polymerization solution including a polyalkylene carbonate resin, an organozinc catalyst, an alkylene oxide and a polymerization solvent; and filtering the polymerization solution after completing the aging.