双马来酰亚胺的改性和发展

系统评述了目前双马来酰亚胺树脂增韧改性的主要方法,对我国双马来酰亚胺树脂改性的研究现状及其发展趋势作了探讨．     

一种改性双马来酰亚胺树脂及其复合材料性能的研究

以二苯甲烷双马来酰亚胺与二烯丙基双酚Ａ共聚,在适当的催化剂作用下,制备了一种改性的双马来酰亚胺树脂．研究了改性的双马来酰亚胺体系的溶解性能、固化反应机理和固化反应动力学特性,并实测了这种树脂基体及其玻璃纤维增强复合材料的机、电、热性能参数。     

Properties of bismaleimide resin modified with polyrotaxane as a stress relaxation material

In this study, 4,4′‐diphenylmethane bismaleimide (BMI)/2,2′‐diallylbisphenol A (DABPA) resin was modified with polyrotaxane (PR) as a stress relaxation material. Based on a dynamic mechanical analysis and various properties of the cured resin, the influence of the motion of PR on the cured properties of BMI/DABPA/PR alloy is discussed. The cyclic molecule α‐cyclodextrin (α‐CD) that is threaded onto the PR axis contains a methacryl group in its side chain that reacts with the allyl group of BMI/DABPA resin. The methacryl group of PR reacted with the allyl group of BMI/DABPA matrix resin to form a transparent and dense network structure, so that the glass transition temperature was increased with increasing PR concentration. In addition, the toughness, impact resistance and adhesiveness of BMI/DABPA resin were improved by modification with PR. These results indicate that the poly(ethylene glycol) chain, which is the axial polymer of the PR, moves in the space formed by the cavities of the threaded α‐CD and the surrounding BMI/DABPA resin matrix in the glassy state, thereby relaxing the internal stress applied to BMI/DABPA/PR resin. The range of applications of BMI/DABPA resin modified with PR may expand into fields requiring high heat resistance in addition to excellent toughness and adhesiveness. © 2018 Society of Chemical Industry     

Eugenol‐Derived Bismaleimide High Performance Resins and Composites Using Diisocyanate as Property Modifier

A new kind of high performance bismaleimide resin with good processability and improved toughness is synthesized by chemical modification of 4,4′‐bismaleimidodiphenylmethane (BMI) by eugenol (EG) and different contents of 4,4′‐diphenylmethane diisocyanate (MDI). MDI‐EG‐BMI resins exhibit good thermal stability for its 5% weight loss temperatures around 300 °C and its residue of 41.61% at 900 °C, which are much higher than those of EG‐BMI resin. Then, the carbon fiber‐reinforced MDI‐EG‐BMI composites are fabricated. The mechanical properties of the composites matrixed by MDI‐EG‐BMI resins are better than those by EG‐BMI resin. For carbon/MDI‐EG‐BMI composites, their glass transition temperatures are higher than 300 °C, and their flexural strength, moduli, and toughness are maintained at a range of 217.47–404.36 MPa, 35.12–48.49 GPa, and 1.16–2.63 MJ m^?3 respectively; with the contents increasing of MDI in the resin formulation, the flexural properties first increase then decrease; comprehensively the composite with 30 wt% MDI has the best mechanical and thermal properties.     

PEK－C增韧BMI／DP树脂的研究

本文以韧性较高的４，４′－氨基二苯甲烷双马来酰亚胺／３，３′－二烯丙基双酚Ａ共聚双马树脂（ＢＭＩ／ＤＰ）作为研究对象，探讨用刚性热塑性树脂ＰＥＫ－Ｃ共混的方法以进一步提高树脂韧性。结果表明，少量的ＰＥＫ－Ｃ能提高ＢＭＩ／ＤＰ树脂韧性，７．９％的ＰＥＫ－Ｃ使树脂ＧＩＣ由２１４Ｊ／ｍ２提高到４０４Ｊ／ｍ２。含活性端基ＰＥＫ－Ｃ和不同分子量的ＰＥＫ－Ｃ对树脂性能产生一定的影响。随ＰＥＫ－Ｃ用量的增加，共混树脂呈两种不同形式的球粒结构。     

3,3'-二叔丁基-4,4'-二氨基二苯甲烷的合成

以4,4'-二氨基二苯甲烷为原料,通过乙酰化反应、烷基化反应、去乙酰化反应,合成了3,3'-二叔丁基-4,4'-二氨基二苯甲烷,采用FTIR证实了其分子结构。通过产率测定研究了各反应阶段的影响因素,确定最佳反应条件:乙酰化反应中,在反应温度215℃下,乙酸过量200%,产率达97%;烷基化反应中,以N,N'-二甲基甲酰胺(DMF)为溶剂,无水三氯化铝为催化剂,在25℃反应温度下,产率达92%;去乙酰化反应中,采用浓盐酸加热,冰浴析出法,产率达98%。通过向4,4'-二氨基二苯甲烷的苯环上引入大体积的叔丁基,提高双马来酰亚胺树脂单体在普通溶剂中的溶解能力,降低预聚体粘度,以便于双马来酰亚胺树脂应用传递模塑成型工艺(RTM)加工。     

带烯键含芴聚芳醚酮增韧改性双马来酰亚胺树脂

采用无溶剂自相溶工艺,将侧链带有烯键的含芴聚芳醚酮(RPFEK)溶解于二烯丙基双酚A（DABPA）,低温下加入4,4′-二氨基二苯甲烷双马来酰亚胺(BMDM)进行熔融共聚,再用高温固化的方式制备了带烯键含芴聚芳醚酮增韧的改性双马来酰亚胺（BMDM/DABPA）复合材料。结果表明,这种复合材料是一种互穿交联网络结构,RPFEK的引入不但对复合材料的玻璃化转变温度无明显影响,而且有利于复合材料热稳定性的提高;可反应烯键的引入提高了RPFEK与BMDM树脂的相容性与界面的粘接作用;与纯BMDM/DABPA树脂相比,10 % RPFEK增韧的BMDM/DABPA树脂的冲击强度从9.0 kJ/m2提高到了15.2 kJ/m2。     

胶粉弹性体的粉末成型及改性

硫化橡胶具有三维的化学网络结构，因此不溶不熔，回收利用非常困难。本文尝试采用粉末成型的技术来制备性能优良的全胶粉弹性体。试验证明，通过在胶粉中加入适量的双马来酰亚胺(BMI)可以制备具有较高使用性能的弹性体。成型温度、时间和BMI的含量会对胶粉弹性体的力学性能产生显著影响。本文认为，加人体系中的BMI会在成型时发生原位反应而接枝的胶粉表面，在胶粉之间形成一种交联的结构，从而提高了弹性体的力学性能。通过拉伸样条的断面电镜照片表明，在体系中加入BMI后，弹性体的界面确实有了很大的改善。     

改性双马来酰亚胺树脂的固化特性

本文采用差示扫描量热（DSC）法研究了QYS91—Ⅱ改性双马树脂的固化反应动力学，利用Kissinger方程和Crane方程分别得到了该树脂固化反应表观活化能E、表观频率因子A和反应级数n，进而提出了该树脂固化成型过程的动力学模型，通过固化反应动力学模型对固化反应特性进行了预测，为改性双马树脂实际应用中固化工艺参数的进一步优化提供了一定的理论参考依据。     

耐热200℃双马改性环氧结构胶膜的研究

研制了一种双马改性环氧结构胶膜,探讨了主要组份对胶粘剂胶接性能的影响,考核了胶粘剂的耐热、耐老化等综合性能。该胶不但对金属之间具有良好的粘接强度,而且对双马树脂基复合材料具有良好的粘接性能。用扫描电镜(SEM)观测固化产物断裂面的微观形态为均相增韧结构;通过示差扫描量热法(DSC)测定该胶的热变形温度为211℃,用热重分析法(TG)测定该胶固化物明显热失重温度为378℃。热力学分析试验表明该胶可以在200℃下长期工作,提高了国内环氧类型膜状胶粘剂的耐温等级。