BMA/AM/AA共聚物的制备

以过氧化苯甲酰(BPO)为引发剂,通过游离的自由基本体聚合来合成多元共聚物并用其制备高性能聚甲基丙烯酰亚胺(PMI)泡沫.采用凝胶渗透色谱、傅立叶变换红外光谱(FTIR)、扫描电子显微镜、差示扫描量热、热重分析等方法表征其结构以及测试其力学性能.结果表明,甲基丙烯酸丁酯(BMA)/丙烯酰胺(AM)二元共聚物与BMA/AM/丙烯酸(AA)三元共聚物的分子量与分布结果显示都出现双峰,且三元泡沫预聚物的分子量较大且分布较宽,符合自由基共聚合的特点,说明第三单体的加入使共聚反应更加完全;从FTIR峰值可以看出,共聚物经过热处理后生成六元酰亚胺环,分子链间发生重排反应,产物发生环化交联;泡沫塑料的孔径分布均匀,且在共聚物热处理前后,热导率由0.275 W/(m·K)降低到0.059 W/(m·K),热分解速率最快时的温度为373℃,隔热性能和耐高温性能较好;泡沫的拉伸强度为6.52 MPa,压缩强度达到36.02 MPa,弯曲强度为2.2 MPa,力学性能优异.

Preparation of BMA/AM/AA Copolymer

Benzoyl peroxide (BPO) was used as initiator to synthesized a multicomponent copolymer by free radical bulk polymerization and used to prepare high-performance polymethacrylimide (PMI) foam,which was subjected to gel permeation chromatography. Fourier transform infrared spectroscopy,scanning electron microscopy,differential scanning calorimetry,thermogravimetric analysis were used to characterize the structure and test its mechanical properties. The results show that the molecular weight distribution of BMA/AM binary copolymer and BMA/AM/AA terpolymer show double peaks, and the ternary foam prepolymer has a large molecular weight and a wide distribution, which is consistent with the characteristics of free radical copolymerization. It indicates that the addition of the third monomer makes the copolymerization reaction more complete;it can be seen from the infrared peak that the copolymer is subjected to heat treatment to form a six-membered imide ring, and a rearrangement reaction occurs between the molecular chains, and the product undergoes cross-linking and cyclizatio. The pore size distribution of the foam is uniform, and the heat conduction before and after the heat treatment of the copolymer. The coefficient is reduced from 0.275 W/(m · K) to 0.059 W/(m · K),and the thermal decomposition rate is the fastest at 373℃. The thermal insulation performance and high temperature resistance are better;the tensile strength of the foam is 6.52 MPa,compressive strength is 36.02 MPa,bending strength is 2.2 MPa,mechanical properties are excellent.