BMI原位复合材料的研究

On Modifying BMI With In Situ Composite Technology

以 BMI为基本组分 ,将原位复合材料用于 BMI树脂的增韧 ,制备了 BMI原位复合材料即RSM/PIO/BMI体系 ;详细研究了 RSM/PIO/BMI未固化体系的反应性和固化树脂的力学性能、耐热性 ,用扫描电镜对固化树脂的断口形貌进行分析。结果表明 ,固化树脂宏观上呈现半透明状 ,微观上具有微纤维结构存在于基体聚合物中。正是由于这种特殊的增韧相结构的存在 ,导致改性RSM/PIO/BMI体系具有良好的抗冲击性能 ,冲击强度为 1 7.6 k J/m2 。

We succeed in producing in the laboratory modified BMI (bismaleimide) with in situ composite technology. Modified BMI consists of three parts: 4,4′ dimaleimideodephenylmathan (BMI), co reactivity monomer with BMI(RSM), and imide oligmer (PIO). We used RSM as solvent for synthesizing PIO and we did not need to separate the RSM/PIO mixture. We dissolved BMI in RSM/PIO to obtain homogeneous modified BMI system and we called it RSM/PIO/BMI system. Then, the final step of in situ composite technology was that we cured RSM/PIO/BMI system to obtain modified BMI. Our experimental findings are four in number as follows: (1) RSM/PIO/BMI has good reactivity at high temperature as its gel time is 8.5 min at 200℃ and it has good stability at low temperature as its gel time is 120 min at 120℃; (2) Fig.2 shows that the exo thermo peak of DTA curve occurs at 245℃; (3) RSM/PIO/BMI cured resin has good heat resistance as its HDT is 277℃ and it has good toughness as its impact strength is 17.6 kJ/m 2 and as its flexural strength is 140 MPa; (4) SEM observation of the morphology of structure of fracture surface of RSM/PIO/BMI sample after its failure under impact shows that there exists micro fabric structure in RSM/PIO/BMI cured resin and this micro fabric structure leads to very good properties of RSM/PIO/BMI cured resin.