摘要:
PBZ polymers are synthesized by the reaction of AA- and BB-monomers. The BB-monomer is conveniently synthesized and isolated as a phosphate salt having a uniform number of phosphate ions associated with each BB-monomer ion. Such high purity monophosphate and diphosphate salts can be obtained by precipitating the monomer from an aqueous acid solution by adjusting the pH balance or from a mixture of phosphoric acid and a volatile, polar, saturated organic liquid at a relatively low temperature.
摘要:
AB-polybenzoxazole monomer, such as 3-amino-4-hydroxybenzoic acid, can be synthesized in high yields from a hydroxy-benzoic acid or related compound in a three-step process of (1) nitration, (2) hydrolysis of the ester, and (3) reduction of the nitro moiety. The monomer is conveniently recovered as a phosphate salt in high purity by precipitating and recrystallizing from a phosphoric acid solution. The monomer may be polymerized in high concentrations in polyphosphoric acid containing high levels of P.sub.2 O.sub.5 to yield a high molecular weight polymer without dehydrohalogenation.
摘要翻译:可以在(1)硝化的三步法中,从羟基 - 苯甲酸或相关化合物以高产率合成AB-聚苯并恶唑单体,例如3-氨基-4-羟基苯甲酸,(2)酯的水解 ,和(3)还原硝基部分。 通过从磷酸溶液中沉淀和重结晶,可以方便地将单体作为高纯度的磷酸盐回收。 单体可以在含有高含量的P 2 O 5的多磷酸中以高浓度聚合,得到高分子量聚合物,而无需脱卤化氢。
摘要:
Polybenzoxazole polymers can be synthesized from BB-monomer having pendant methyl groups. The resulting polymer has pendant methyl groups, which can be used to cross-link the polymers.
摘要:
AB-polybenzoxazole monomer, such as 3-amino-4-hydroxybenzoic acid, can be synthesized in high yields from a hydroxy-benzoic acid or related compound in a three-step process of (1) nitration, (2) hydrolysis of the ester, and (3) reduction of the nitro moiety. The monomer is conveniently recovered as a phosphate salt in high purity by precipitating and recrystallizing from a phosphoric acid solution.
摘要:
AB-polybenzoxazole monomer, such as 3-amino-4-hydroxybenzoic acid, can be synthesized in high yields from a hydroxy-benzoic acid or related compound in a three-step process of (1) nitration, (2) hydrolysis of the ester, and (3) reduction of the nitro moiety. The monomer is conveniently recovered as a phosphate salt in high purity by precipitating and recrystallizing from a phosphoric acid solution.
摘要:
The present invention encompasses non-phase-separated thermoplastic block copolymers containing rigid rod PBZ blocks and thermoplastic PBZ blocks; dopes and compositions containing those block copolymers; a process for making shaped articles from thermoplastic block copolymers containing rigid rod PBZ blocks and thermoplastic PBZ blocks; and shaped articles made by that process.
摘要:
A caddy assembly for carrying a fishing rod includes a tripod that may be positioned on a support surface. A head is movably coupled to the tripod. The head is positionable at a selected angle with respect to the tripod. A handle is coupled to the head. The handle may be gripped. A carrier is coupled to the head. The carrier may carry a fishing rod.