The present application relates to a phthalonitrile resin and the like. The present application can provide a phthalonitrile resin, and a polymerizable composition and prepolymer using the same, which can exhibit excellent curability, a suitable processing temperature and a wide process window, and form a composite having excellent physical properties. Also, according to the present invention, there may be provided a phthalonitrile resin, and a polymerizable composition and prepolymer using the same, which can exhibit appropriate viscosity characteristics and thus provide a final product without deterioration of mechanical physical properties or the like due to bubbles generated during processing.

Methods of vulcanization using a high content sulfur polymer, instead of elemental sulfur, have been developed. These high sulfur content polymers are referred to as Chalcogenide Hybrid Inorganic/Organic Polymers (CHIP) materials and have good polymer compatibility in that they are soluble in a number of polymers. Furthermore, CHIP materials may have weaker bonds than the SS bonds of elemental sulfur and thus provide for a higher crosslinking efficiency vulcanization.

Methods of vulcanization using a high content sulfur polymer, instead of elemental sulfur, have been developed. These high sulfur content polymers are referred to as Chalcogenide Hybrid Inorganic/Organic Polymers (CHIP) materials and have good polymer compatibility in that they are soluble in a number of polymers. Furthermore, CHIP materials may have weaker bonds than the SS bonds of elemental sulfur and thus provide for a higher crosslinking efficiency vulcanization.

Compositions that are curable by free radical redox reactions are disclosed. Free radical curing reactions between polythiols and polyalkyenyls are initiated by the reaction of metal complexes and organic peroxides. The compositions are useful as sealants.

Compositions that are curable by free radical redox reactions are disclosed. Free radical curing reactions between polythiols and polyalkyenyls are initiated by the reaction of metal complexes and organic peroxides. The compositions are useful as sealants.

Disclosed is a triazine ring-containing polymer including a repeating unit represented by Formula (1) and has a number average molecular weight of greater than about 20000 g/mol and less than or equal to about 50000 g/mol:

##STR00001## wherein, in Formula (1), R.sup.1 is each independently a C1 to C5 alkyl group and R.sup.2 is each independently a divalent group having at least one aromatic hydrocarbon group.

An organic-inorganic hybrid composition including a polymer having a triazine ring structure in a main chain of the polymer (A);

an inorganic particulate (B); and a surface-treating agent having a triazine ring structure represented by Formula (1)(C):

##STR00001## wherein, in Formula (1), R.sub.1 is a carboxyl group, a phosphoric acid group, a sulfo group, or a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted aralkyl group, or a substituted or unsubstituted amino group, wherein a number median diameter (Dn50) of the inorganic particulate (B) is greater than or equal to about 1 nm and less than or equal to about 20 nm.

A curable composition for forming a high refractive index optical material including an episulfide compound, a cyclic disulfide compound, and a reducing agent, and an optical material comprising a cured product of the curable composition.

A curable composition for forming a high refractive index optical material including an episulfide compound, a cyclic disulfide compound, and a reducing agent, and an optical material comprising a cured product of the curable composition.

A method for preparing polyarylene sulfide that can control a viscosity grade thereof by adjusting the molar ratio of water and amide-based compounds present in a polymerization reaction.