Department of Chemistry, Rutgers University-Newark, 73 Warren Street, Newark, NJ 07102, USA.
Molecules. 2018 Feb 13;23(2):405. doi: 10.3390/molecules23020405.
The use of thermo-reversible Lewis Pair (LP) interactions in the formation of transient polymer networks is still greatly underexplored. In this work, we describe the synthesis and characterization of polydimethylsiloxane/polystyrene (PDMS/PS) blends that form dynamic Lewis acid-Lewis base adducts resulting in reversible crosslinks. Linear PS containing 10 mol % of di-2-thienylboryl pendant groups randomly distributed was obtained in a two-step one-pot functionalization reaction from silyl-functionalized PS, while ditelechelic PDMS with pyridyl groups at the chain-termini was directly obtained via thiol-ene "click" chemistry from commercially available vinyl-terminated PDMS. The resulting soft gels, formed after mixing solutions containing the PDMS and PS polymers, behave at room temperature as elastomeric solid-like materials with very high viscosity (47,300 Pa·s). We applied rheological measurements to study the thermal and time dependence of the viscoelastic moduli, and also assessed the reprocessability and self-healing behavior of the dry gel.
在形成瞬态聚合物网络中，热可逆路易斯对（LP）相互作用的应用仍未得到充分探索。在这项工作中，我们描述了聚二甲基硅氧烷/聚苯乙烯（PDMS/PS）共混物的合成和表征，这些共混物形成了动态路易斯酸-路易斯碱加合物，从而产生了可逆交联。通过两步一锅法官能化反应，从硅烷基官能化的 PS 中获得了含有 10mol%二噻吩基硼基侧基的线性 PS，而末端带有吡啶基的双官能 PDMS 则通过商业可得的乙烯基封端 PDMS 的硫醇-烯“点击”化学直接获得。将含有 PDMS 和 PS 聚合物的溶液混合后形成的软凝胶，在室温下表现为具有高粘度（47,300 Pa·s）的弹性固体状材料。我们应用流变学测量来研究粘弹性模量的热依赖性和时间依赖性，还评估了干凝胶的可再加工性和自修复行为。
