Tang Maozhu, Zhang Rong, Li Shiqi, Zeng Jian, Luo Mingchao, Xu Yun-Xiang, Huang Guangsu
College of Polymer Science & Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu, 610065, China.
Angew Chem Int Ed Engl. 2018 Nov 26;57(48):15836-15840. doi: 10.1002/anie.201809339. Epub 2018 Nov 2.
Natural rubber is one of most famous self-reinforced rubbers thanks to the phenomenon of strain-induced crystallization. It is usually used in a vulcanized form to enhance the mechanical strength but this results in recycling issues. Herein a thermoplastic analogue of vulcanized natural rubber is obtained as a structural mimic. Terminally functionalized polyisoprene rubber B-4A-PIP was prepared by using tetra-analine as physical crosslinking units. The strong binding of tetra-analine groups gave B-4A-PIP a high tensile strength (15 MPa) and breaking strain of 890 %, which is much higher than those of undecorated copolymer B-OH-PIP. B-4A-PIP has a similar onset strain of crystallization and crystallization index to vulcanized natural rubber. Randomly functionalized polyisoprene R-4A-PIP showed a much lower mechanical strength and SIC properties although R-4A-PIP and B-4A-PIP possessed similar molecular weights and amounts of tetra-analine groups.
由于应变诱导结晶现象，天然橡胶是最著名的自增强橡胶之一。它通常以硫化形式使用以提高机械强度，但这会导致回收问题。在此，获得了一种硫化天然橡胶的热塑性类似物作为结构模拟物。通过使用四苯胺作为物理交联单元制备了端基功能化聚异戊二烯橡胶B-4A-PIP。四苯胺基团的强结合赋予B-4A-PIP高拉伸强度（15 MPa）和890%的断裂应变，这远高于未修饰的共聚物B-OH-PIP。B-4A-PIP具有与硫化天然橡胶相似的结晶起始应变和结晶指数。随机功能化的聚异戊二烯R-4A-PIP显示出低得多的机械强度和应变诱导结晶性能，尽管R-4A-PIP和B-4A-PIP具有相似的分子量和四苯胺基团数量。
