A triazine ring-containing polymer, having a structural unit represented by the following formula (1), in which a peak top molecular weight obtained by gel permeation chromatography is 19,000 or less.

##STR00001##

This disclosure describes new compositions and methods related to photoresponsive poly(hexahydrotriazines) and related polymers. In an embodiment, a method of patterning a substrate includes forming a liquid poly(hemiaminal) material by a process that includes forming a reaction mixture comprising a polar solvent, paraformaldehyde, and an aminobenzene compound having photoreactive groups, and heating the reaction mixture at a temperature up to 50° C. The method further includes applying the liquid poly(hemiaminal) material to a substrate; patterning the liquid poly(hemiaminal) material with UV light; and curing the liquid poly(hemiaminal) material to form a cured poly(hexahydrotriazine) polymer.

The polymerizable composition of the present application may exhibit a wide process window to have excellent workability, and may form a phthalonitrile resin having excellent heat resistance or a prepolymer thereof.

Polyhemiaminal (PHA) and polyhexahydrotriazine (PHT) materials are modified by 1,4 conjugate addition chemical reactions to produce a variety of molecular architectures comprising pendant groups and bridging segments. The materials are formed by a method that includes heating a mixture comprising solvent(s), paraformaldehyde, aromatic amine groups, aliphatic amine Michael donors, and Michael acceptors, such as acrylates. The reaction mixtures may be used to prepare polymer pre-impregnated materials and composites containing PHT matrix resin.

A triazine-ring-containing polymer characterized by including a repeating unit structure represented by formula (1).

##STR00001##

[In the formula, R and R′ each independently represent a hydrogen atom, an alkyl group, an alkoxy group, an aryl group, or an aralkyl group, and Ar represents at least one selected from the group shown by formulas (2) and (3).

##STR00002##

[in the formulas, W.sup.1 and W.sup.2 each independently represent CR.sup.1R.sup.2 (R.sup.1 and R.sup.2 each independently represent a hydrogen atom or a C1-10 alkyl group optionally substituted by a halogen atom (where these together may form a ring)), C═O, S, SO, or SO.sub.2.]]

The present disclosure relates to a polyimide precursor composition comprising an amic acid ester oligomer of formula (I): ##STR00001## wherein r, R.sub.x, G, P and R are as defined in the specification. Also, a use of the polyimide precursor composition and a polyimide made from the polyimide precursor composition.

The invention generally relates to novel poly-substituted cis stilbenes, their synthesis, their purification, and their use in thermoset resins. These novel cis stilbenes give rise to thermoset resins with greatly improved processing characteristics such as lower melting temperature and lower viscosity; resulting in polymers and composites having greatly improved thermal stability.

A triazine ring-containing polymer having a high refractive index and a low birefringence, and being capable of being subjected to injection molding, wherein the polymer having a repeating unit of *-[A-B-]-*, including a structural unit A derived from a triazinedithiol compound, and a structural unit B including an aromatic hydrocarbon group; and a thermoplastic resin, a thermoplastic article, and an optical part including the polymer.

A fire retardant (FR) composite composition, including a liquid polymer, wherein the liquid polymer includes a photopolymer including at least two of a first molecule, a second molecule, and a third molecule, a FR thermoset, and a photoinitiator.

Disclosed are a triazine ring-containing polymer having a repeating unit that comprises a structural unit derived from a triazinedithiol compound, the triazine ring-containing polymer having a yellowness index of less than 3 and comprising terminal SH groups, wherein at least a portion of the SH groups are capped with a hydrocarbon group, and a number of the SH groups in the triazine ring-containing polymer is less than about 1×10.sup.18 per gram of the polymer, and a thermoplastic article and optical part including the polymer.