改性BMI树脂工艺、结构与性能的研究

The Relation of Structures and Properties with Modification Technology of BMI Resin

提出了前原位聚合(PI)刚性齐聚物改性BMI的新方法,以BMI的共聚单体(RS)为溶剂,前原位聚合了不同分子结构的PI齐聚物对BMI进行改性,研究了PI齐聚物的分子结构,混容工艺对改性BMI树脂性能的影响;为了证实这种改性新方法的优越性,研究改性BMI树脂工艺、结构与性能的关系.还采用传统方法合成聚酰亚胺齐聚物,并用热熔法使之在BMI共聚单体中混容并用于BMI树脂改性进行对比.在PI分子结构相同的条件下,前原位聚合法合成聚酰亚胺齐聚物改性得到性能较好的改性BMI树脂,特别是固化物在增韧的同时,其HDT高于未增韧树脂固化物.这一点与其它方法改性所得到的结果不同.采用前原位聚合PI齐聚物对BMI树脂改性,改善PI齐聚物分子结构的柔顺性,有利于提高BMI树脂的韧性.

The relation of structures and properties with modification technology of BMI resin is studied. A new method for increasing toughness of BMI resin, so called preinsitu polymerization (PISP) is employed. Three kinds of rigid oligmers (PI) used as modifier are polymerized in RS that can react with BMI and use as solvent in PISP, and we do not need to separate the mixture PI/RS. BMI is dissolved in the RS with PI to obtain modified BMI homogenous prepolymer (PI/RS/BMI). Curing reaction is studied by means of DTA and a gel characteristics analysis. In final step we cured the modified BMI system and obtained cured modified BMI resin and the properties of cured resin were investigated. PI/RS/BMI has good reactivity at high temperature and has good stability at low temperature, and the gel time of PI/RS/BMI resin is longer than RS/BMI at same temperature. PI/RS/BMI cured resin has excellent heat resistance as their HDT exceeds 270 ℃. PI/RS/BMI cured resin by PISP has excellent toughness and PI/RS/BMI cured resin by simplly melting mixture has poor toughness. The more toughness of PI, the more toughness of PI/RS/BMI cured resin.