This invention provides a polyolefin-based resin composition excellent in mechanical strength and elasticity. The polyolefin-based resin composition comprises a polyolefin-based resin, and, per 100 parts by mass of the polyolefin-based resin, 0.05 to 10 parts by mass of an aliphatic polycarbonate resin and 0.01 to 2 parts by mass of an acid modified polypropylene.

The present invention relates to a polycarbonate resin containing, in the molecule, a structure represented by the following formula (1):

##STR00001##

wherein X has a structure represented by any one of the following formulae (2) to (4):

##STR00002##

wherein each of R.sup.1 to R.sup.4 independently represents a hydrogen atom or an organic group having a carbon number of 1 to 30; the organic group may have an arbitrary substituent, and any two or more members of R.sup.1 to R.sup.4 may combine with each other to form a ring, which is excellent in heat resistance, transparency, light resistance, weather resistance and mechanical strength.

The present invention addresses the problem of providing a resin having a high Abbe number and a small difference in hygroscopic expansion coefficient with respect to a polycarbonate resin having a low Abbe number and a high refractive index. The above problem can be solved by a polycarbonate resin including structural units represented by general formula (1). In general formula (1), R represents H, CH.sub.3, or C.sub.2H.sub.5.

##STR00001##

The present invention relates to a manufacturing method of a polyalkylene carbonate resin capable of suppressing agglomeration among catalyst particles during polymerization to maintain an excellent catalytic activity in a polymerization process, wherein the manufacturing method of a polyalkylene carbonate resin may include polymerizing epoxide and a monomer including carbon dioxide in the presence of a zinc dicarboxylate-based organic zinc catalyst and a dispersant, and the dispersant may include at least one selected from the group consisting of C1-C10 alkyl acrylate, C1-C10 alkyl methacrylate, C1-C20 monocarboxylic acid having an oxo group in a molecular structure, and a polyether-based polymer having C2-C6 alkylene oxide repeating units.

A process for preparing polyether carbonate alcohols by attaching cyclic ethylene carbonate to an H-functional starter substance in the presence of a catalyst, characterized in that at least one compound according to formulae X[VO.sub.3] (1), Y.sub.2[WO.sub.4] (2), or Y.sub.3[VO.sub.4] (3), wherein X=alkali metal, preferably potassium or cesium, and Y=potassium or cesium, is used.

The present invention provides novel metal complexes, methods of making, and methods of using the same.

The present disclosure provides a Lewis acid-base pair catalytic initiator and an application thereof. The Lewis acid-base pair catalytic initiator includes a Lewis acid and a Lewis base, the Lewis acid having a structural general formula as shown in formula (I) and the Lewis base having a structural general formula as shown in formula (II); wherein: the A is selected from element Baron or element Aluminum; the R.sub.1, R.sub.2, R.sub.3, R.sub.4 are independently selected from alkyl, alkoxy, aryl or halogen groups; the alkyl or alkoxy have a carbon number being equal to or greater than 1 to equal to or less than 16; the aryl contains substituents with the number being equal to or less than 5, the substituents being selected from methyl, methoxy or halogen; n is selected from an integer from 1 to 16.

In one aspect, the present disclosure encompasses polymerization systems for the copolymerization of CO.sub.2 and epoxides comprising 1) a catalyst including a metal coordination compound having a permanent ligand set and at least one ligand that is a polymerization initiator, and 2) a chain transfer agent having two or more sites that can initiate polymerization. In a second aspect, the present disclosure encompasses methods for the synthesis of polycarbonate polyols using the inventive polymerization systems. In a third aspect, the present disclosure encompasses polycarbonate polyol compositions characterized in that the polymer chains have a high percentage of —OH end groups and a high percentage of carbonate linkages. The compositions are further characterized in that they contain polymer chains having an embedded polyfunctional moiety linked to a plurality of individual polycarbonate chains.

A process for producing a polyol block copolymer in a multiple reactor system including a first and second reactor in which a first reaction takes place in the first reactor and a second reaction takes place in the second reactor. The first reaction is the reaction of a carbonate catalyst with CO.sub.2 and epoxide, in the presence of starter and/or solvent to produce polycarbonate polyol copolymer and the second reaction is the reaction of DMC catalyst with the polycarbonate polyol compound of the first reaction and epoxide to produce polyol block copolymer. The product of the first reaction is fed into the second as crude reaction mixture, the epoxide and the polycarbonate polyol compound of the first reaction are fed in a continuous or semi-batch manner, and/or the product of the first reaction has neutral or alkaline pH on addition to the second. The invention further relates to the copolymers and products incorporating such copolymers.

A polyol block copolymer comprising a polycarbonate block, A (-A′-Z′—Z—(Z′-A′).sub.n-), and polyethercarbonate blocks, B. The polyol block copolymer has the polyblock structure:

B-A′-Z′—Z—(Z′-A′-B).sub.n

wherein n=t−1 and wherein t=the number of terminal OH group residues on the block A; and wherein each A′ is independently a polycarbonate chain having at least 70% carbonate linkages, and wherein each B is independently a polyethercarbonate chain having 50-99% ether linkages and at least 1% carbonate linkages; and wherein Z′—Z—(Z′).sub.n is a starter residue. A process of producing a polyol block copolymer from a two step process carried out in two reactors, and products and compositions incorporating such copolymers.