The present disclosure discloses a photosensitive resin composition and a use the same. The resin composition of the present disclosure includes 40-70 parts by weight of an alkali-soluble resin, 20-50 parts by weight of a photopolymerizable monomer, 0.5-10.0 parts by weight of a photoinitiator, and 0.1-10.0 parts by weight of additives. The photopolymerizable monomer includes 0.5-15.0 parts by weight of a monomer containing carbonate structure. The photosensitive resin composition is used as a dry film resist.

Provided is a resin composition comprising: a polycarbonate resin (A) containing, as main repeating units, a unit (a-1) represented by the following formula (a-1) ##STR00001##
and a unit (a-2) represented by the following formula (a-2) ##STR00002##
(wherein, W represents a C.sub.1-20 alkylene group or a C.sub.6-20 cycloalkylene group, R represents a branched or linear-chain C.sub.1-20 alkyl group or a C.sub.6-20 cycloalkyl group optionally substituted, and m represents an integer of 0 to 10) and an acrylic resin (B), and the polycarbonate resin and the acrylic resin are in a weight ratio of 40:60 to 99:1, wherein the resin composition has a single glass transition temperature, which is in the range of 90° C. to 150° C., and the resin composition has excellent transparency, chemical resistance, surface hardness and heat resistance, and has a low photoelastic coefficient.

A high-barrier biodegradable Doypack and a preparation method therefor. The Doypack consists of two parts, a high-barrier biodegradable self-sealing strip and a five-layered composite high-barrier biodegradable Doypack body. The main base materials of the high-barrier biodegradable self-sealing strip are PLGA and PPC that have excellent barrier performance; and the five-layered composite high-barrier biodegradable Doypack body consists of single side glossy white Kraft paper, a bonding layer, a first barrier layer, a second barrier layer, and a heat-sealing layer, which are integrally formed by using a process combining four-layer co-extrusion and lamination. Compared to conventional non-degradable Doypacks, the high-barrier biodegradable Doypack is substantially equivalent in terms of the physical and mechanical performance and heat-sealing performance, but has a superior barrier performance, and is biodegradable.

A biodegradable triblock copolymer comprising: an A-B-A′ structure wherein the A and A′ blocks each include polylactide, the B block includes from about 55 to about 100 mole percent of polytrimethylene carbonate and 0 to about 45 mole percent polylactide, and the biodegradable triblock copolymer overall includes from about 15 to about 25 mole percent of the polytrimethylene carbonate and from about 75 to about 85 mole percent of the polylactide. Also provided are compositions and implantable medical devices made therefrom.

The present disclosure belongs to the field of organic synthesis, and particularly relates to a ring-opening polymerization method for a cyclic monomer. A specific solution is that a Lewis acid-base pair is used to catalyze ring-opening polymerization of the cyclic monomer in the presence of an initiator. By using the Lewis acid-base pair as a catalyst, on one hand, a range of a ring-opening polymerization catalyst is widened, and on the other hand, this catalyst achieves a higher catalytic efficiency and is milder in comparison with previously reported strong acid or strong base catalysts. In addition, through a bifunctional activation mechanism, this catalyst system activates the monomer and simultaneously activates the initiator or a chain end, and has the characteristics of high efficiency in comparison with the reported monomer activation mechanism or chain end activation mechanism. By adopting the catalyst, a polyester product with a target molecular weight can be synthesized in a controlled manner as required, with a narrower molecular weight distribution index, a high product yield, a high product conversion rate and no monomer or metal residues.

There is a process for the preparation of polypropylene carbonate having the step of copolymerization of propylene oxide and carbon dioxide (CO.sub.2) in the presence of a catalytic system including: at least one catalyst selected from complexes of a transition metal having general formula (I):

##STR00001## at least one co-catalyst selected from: (a) ionic compounds having general formula (II):

##STR00002## and (b) ionic compounds having general formula (III)

##STR00003##

The present invention relates to a polymer composition having improved processability by containing a polyalkylene carbonate resin and a film using the same.

A method of continuously producing a polyol includes: (i) feeding a solid catalyst into a continuous stirred tank reactor (CSTR); (ii) contacting a reaction mixture comprising one or more epoxides and carbon dioxide with the solid catalyst and a chain transfer agent comprising a plurality of sites capable of initiating copolymerization of epoxides and carbon dioxide in the CSTR; (iii) allowing polymerization reaction to proceed until a desired molecular weight polyol has formed; and (iv) terminating the polymerization reaction.

The invention provides polymer compositions, compounds, processes, and methods of use of the polymers for biodegradable consumer plastics, adhesives, e.g., bioadhesives, pressure sensitive adhesives and thermos-responsive adhesives.

Provided is a method for producing an oligocarbonate polyol devoid of aromatic groups and phenolic functions, comprising a step of polycondensation by transesterification of monomers (A1) and/or dimers (A2) and of diol monomers (B1) and/or of triol monomers (B2), in a particular molar ratio, in order to obtain an oligocarbonate polyol having a molar mass of less than 5000 g/mol and at least two hydroxyl-type chain ends, the monomer (A1) corresponding to the following formula: (A1) and the dimer (A2) corresponding to the following formula: (A2) as well as the oligocarbonate polyol that can be obtained by this method and the polycarbonate that can be obtained by reacting this oligocarbonate with a polyisocyanate. ##STR00001##