Diels-Alder反应可控制备交联等规聚丙烯  

Controlled Preparation of Crosslinked Isotactic Polypropylene via Diels-Alder Reaction

作　　者：张德广 李彦国[1] 崔磊[1] 李悦生[3] 

机构地区：[1]中国科学院长春应用化学研究所高分子复合材料工程实验室,长春130022 [2]中国科学院大学,北京100049 [3]天津大学材料科学与工程学院,天津300372

出　　处：《应用化学》2018年第2期174-180,共7页Chinese Journal of Applied Chemistry

基　　金：国家自然科学基金(21234006)项目资助

摘　　要：交联改性可以提升聚合物材料的机械性能、热稳定性及化学稳定性。含有蒽基团的高质均分子量等规聚丙烯(iPP)可由配位共聚合反应制得,随后通过双官能的马来酰亚胺试剂与iPP中悬挂蒽基团间的DielsAlder反应可以成功制备交联的iPP膜材料。材料的交联度可以通过凝胶重量分析及膜红外分析得出,并由制备过程中交联剂的加入量有效地调控。通过示差扫描量热仪(DSC)与广角X射线衍射仪(WAXD)表征发现,随交联度增加,交联改性限制了分子链的运动,iPP的结晶度逐渐降低、结晶能力逐渐下降。对交联材料的动态热机械分析仪(DMA)测试表明,随交联度增加,iPP的损耗模量逐渐降低,材料韧性变差。交联iPP的Tg逐渐升高,说明材料的耐热性得到提升。由于交联形成了聚合物链间的交联网络,形成了更多受力点并且限制了聚合物链的自由移动,交联材料的拉伸强度随交联度的升高而增加,而断裂伸长率逐渐下降。Cross-linking is a commonly used method for polyolefin modification to improve the material’ s mechanical properties,thermo-and chemical resistance. High molecular mass（ Mw） i PPs containing reactive anthracene groups were synthesized by coordination copolymerization. Crosslinked i PP films could be prepared by adding bi-functional N,N’-1,4-phenylene bismaleimide as a crosslinker to react with the pendent anthracene groups during the solvent casting process of the film. The cross-linking degree of the films could be easily tuned by the addition of the crosslinker. Characteristic absorption bands in Fourier transform infrared（ FT-IR） spectra of the crosslinked films and gravimetric analysis of the insoluble portion could be used to determine the crosslinking degree. Differential scanning calorimetry（ DSC） and wide-angle X-ray diffraction（ WAXD） analysis revealed that the crystallinity and crystallization capability of the films decreased followed with the increase of cross-linking degree,which were mainly caused by the restricted chain movement. On the other hand,according to DMA analysis,the loss modulus dropped gradually with the increase of cross-linking degree,indicating the loss of toughness brought by cross-linking. The increased Tgdetected from loss angle curves indicated the enhancement of thermoresistance. The tensile stress of the crosslinked i PP films were improved by forming polymer network containing more force bearing point,while the elongation at break dropped drastically because of the chains’ poor movability.

关 键 词：聚丙烯 DIELS-ALDER反应 交联 

分 类 号：O631.5[理学—高分子化学]