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 invention relates to expandable, polymerizable compositions comprising at least one benzoxazine and at least one cyclic carbonate, to polymerization products of these expandable, polymerizable compositions, to a process for preparing these polymerization products as well as to uses of these expandable, polymerizable compositions. The present invention is based on the surprising finding that copolymerizing benzoxazine monomers with cyclic carbonate monomers results in novel copolymers having unforeseeably high expansion rates, wherein the properties (e.g. solid/brittle, solid/soft, rubbery) of the resulting copolymers can be easily and reproducibly tuned/adjusted, depending on the ratio of the benzoxazine equivalents/cyclic carbonate equivalents present in the composition and copolymer, respectively.

The present invention relates to expandable, polymerizable compositions comprising at least one benzoxazine and at least one cyclic carbonate, to polymerization products of these expandable, polymerizable compositions, to a process for preparing these polymerization products as well as to uses of these expandable, polymerizable compositions. The present invention is based on the surprising finding that copolymerizing benzoxazine monomers with cyclic carbonate monomers results in novel copolymers having unforeseeably high expansion rates, wherein the properties (e.g. solid/brittle, solid/soft, rubbery) of the resulting copolymers can be easily and reproducibly tuned/adjusted, depending on the ratio of the benzoxazine equivalents/cyclic carbonate equivalents present in the composition and copolymer, respectively.

The present invention relates to a process for producing a polycarbonate from a diphenol or two or more different diphenols and a carbonyl halide by the interfacial process. It is a feature of the process according to the invention that it is carried out on the basis of a chlorohydrocarbon or a mixture of a mixture of two or more chlorohydrocarbons using an organic solvent. An organic solvent is also provided.

The present invention provides a process for removing gaseous constituents dissolved in liquid reaction mixtures in the copolymerization of alkylene oxide and carbon dioxide, characterized in that (η) prior to decompression the liquid reaction mixture has a pressure of 5.0 to 100.0 bar (absolute), wherein the following process stages are performed in the specified sequence: (i) decompression of the reaction mixture by at least 50% of the prevailing pressure, (ii) subsequent droplet separation with first defoaming and (iii) subsequent bubble separation with second defoaming to clarify the liquid phase, wherein the process stages (i) to (iii) are performed one or more times until the resulting reaction mixture has a pressure of 0.01 to <5.00 bar (absolute), and also a process for preparing polyethercarbonate polyols comprising the process stages (i)-(iii).

The present disclosure relates to a method for treating a solvent in wastewater generated in a polycarbonate production process. More specifically, the present disclosure relates to a method for treating a solvent in wastewater generated in a polycarbonate production process, which can easily recover a high purity solvent regardless of the concentration of the solvent by using a membrane distillation method to reuse it, and contribute to energy savings.

The present disclosure relates to a method for separating an organic zinc catalyst dispersed in a polyalkylene carbonate resin solution by filtering the polyalkylene carbonate resin solution using a composite filtering membrane, which is a composite material comprising a hydroxyl group-containing material and polyolefin material and has a form in which one or both surfaces of the polyolefin material is coated with the hydroxyl group-containing material.

A process for preparing polyol, wherein, in a first process stage, a diol is prepared by a process comprising: (1-i) adding alkylene oxide and carbon dioxide onto an H-functional starter substance in the presence of a catalyst to obtain polyethercarbonate polyol and a cyclic carbonate, (1-ii) separating the cyclic carbonate from the resulting reaction mixture from step (1-i), (1-iii) hydrolyzing the cyclic carbonate separated from step (1-ii) to carbon dioxide and diol, and (1-iv) optionally purifying the diol resulting from step (1-iii) by distillation.

Ways of preparing a partially crystalline polycarbonate powder are provided that include dissolving an amorphous polycarbonate in a polar aprotic solvent to form a first solution of solubilized polycarbonate at a first temperature. The first solution is then cooled to a second temperature, the second temperature being lower than the first temperature, where a portion of the solubilized polycarbonate precipitates from the first solution to form a second solution including the partially crystalline polycarbonate powder. Certain partially crystalline polycarbonate powders resulting from such methods are particularly useful in additive manufacturing processes, including powder bed fusion processes.

Ways of preparing a partially crystalline polycarbonate powder are provided that include dissolving an amorphous polycarbonate in a polar aprotic solvent to form a first solution of solubilized polycarbonate at a first temperature. The first solution is then cooled to a second temperature, the second temperature being lower than the first temperature, where a portion of the solubilized polycarbonate precipitates from the first solution to form a second solution including the partially crystalline polycarbonate powder. Certain partially crystalline polycarbonate powders resulting from such methods are particularly useful in additive manufacturing processes, including powder bed fusion processes.