The present invention relates to a polyarylene sulfide resin composition having good processability and showing excellent properties due to its more improved miscibility with other polymer materials or fillers, and a formed article. Such polyarylene sulfide resin composition includes a polyarylene sulfide including a disulfide repeating unit in the repeating units of the main chain; and at least one component selected from the group consisting of a thermoplastic resin, a thermoplastic elastomer, and a filler.

The present invention relates to a polyarylene sulfide resin composition having good processability and showing excellent properties due to its more improved miscibility with other polymer materials or fillers, and a formed article. Such polyarylene sulfide resin composition includes a polyarylene sulfide including a disulfide repeating unit in the repeating units of the main chain; and at least one component selected from the group consisting of a thermoplastic resin, a thermoplastic elastomer, and a filler.

To provide a degradable polyethylene glycol derivative in which polyethylene glycol chains are linked by a disulfide linker capable of accurately controlling the degradation rate under different reductive environments in the living body, and whose division rate into a polyethylene glycol chain of low molecular weight in the living body is able to be accurately controlled. A degradable polyethylene glycol derivative represented by formula (1). R.sup.1, R.sup.2, R.sup.3 and R.sup.4 represent each independently a hydrogen atom or a hydrocarbon group having from 1 to 6 carbon atoms, and at least one of R.sup.1, R.sup.2, R.sup.3 and R.sup.4 is the hydrocarbon group; P.sup.1 is a straight-chain or branched polyethylene glycol chain having a number of ethylene glycol units of 3 or more; P.sup.2 is a straight-chain polyethylene glycol chain having a number of ethylene glycol units of 3 or more; w is an integer of 1 to 8; u is an integer of 1 to 10; X.sup.1 is a chemically reactive functional group; and Z.sup.1, Z.sup.2 and Z.sup.3 are each independently a selected divalent spacer.

##STR00001##

The present disclosure relates to a cyclic polysulfane-based polymer, a cyclic polysulfane-polynorbornene block copolymer, a method of preparing the cyclic polysulfane-based polymer, a method of preparing the cyclic polysulfane-polynorbornene block copolymer, and a film including the cyclic polysulfane-polynorbornene block copolymer.

The present disclosure relates to a cyclic polysulfane-based polymer, a cyclic polysulfane-polynorbornene block copolymer, a method of preparing the cyclic polysulfane-based polymer, a method of preparing the cyclic polysulfane-polynorbornene block copolymer, and a film including the cyclic polysulfane-polynorbornene block copolymer.

The present invention provides a composition for an optical material containing a ring compound (a) represented by formula (1), an episulfide compound (b), and sulfur (c), wherein the content of the ring compound (a) in the composition for an optical material is in the range of 5-70 mass %, the content of the episulfide compound (b) is in the range of 20-90 mass %, and the content of the sulfur (c) is in the range of 1-39 mass %. (In the formula, X represents S, Se or Te. a to f=0 to 3, 8(a+c+e)1, 8(b+d+f)2, and (b+d+f)(a+c+e).) This composition for an optical material has a high refractive index as an optical characteristic, and has sufficient heat resistance and good mold release characteristics. ##STR00001##

A process for preparing a sulfur copolymer, a sulfur copolymer, and a polymer composition containing one or more sulfur copolymers are provided. The process involves copolymerizing a cyclic monothiocarbonate compound of formula

##STR00001##

wherein
R.sup.1 and R.sup.2 are independently of one another hydrogen, C.sub.1-C.sub.18-alkyl, C.sub.1-C.sub.18-alkyl substituted with halogen or interrupted with O or S; C.sub.6-C.sub.18-aryl or C.sub.6-C.sub.12-aryl substituted with C.sub.1-C.sub.4-alkyl, C.sub.1-C.sub.4-alkoxy, C.sub.1-C.sub.4-alkylthio or halogen; with elemental sulfur in the presence of a polymerization initiator.

This process for synthesizing thiopolymers involves feeding elemental sulfur or sulfides and unsaturated hydrocarbons into an extruder. The extruder is comprised of a screw and a barrel. The screw is rotated so as to pressurize, heat and mix the sulfur or sulfides and unsaturated hydrocarbon to induce inverse vulcanization thereby producing thiopolymers such as polymeric polysulfides. The invented process can be accomplished by using sulfur which becomes molten at the conditions in the extruder or is preheated and unsaturated hydrocarbons as the starting material. The materials are fed through one or more extruders so as to induce mixing and reaction of the materials forming polysulfides.

This process for synthesizing thiopolymers involves feeding elemental sulfur or sulfides and unsaturated hydrocarbons into an extruder. The extruder is comprised of a screw and a barrel. The screw is rotated so as to pressurize, heat and mix the sulfur or sulfides and unsaturated hydrocarbon to induce inverse vulcanization thereby producing thiopolymers such as polymeric polysulfides. The invented process can be accomplished by using sulfur which becomes molten at the conditions in the extruder or is preheated and unsaturated hydrocarbons as the starting material. The materials are fed through one or more extruders so as to induce mixing and reaction of the materials forming polysulfides.

Provided is a sealant sheet formed as a sheet. The sealant sheet comprises an epoxy group-containing polysulfide. The epoxy group-containing polysulfide has a disulfide structure and an epoxy group in its molecule.