Maksym Paulina, Tarnacka Magdalena, Heczko Dawid, Knapik-Kowalczuk Justyna, Mielańczyk Anna, Bernat Roksana, Garbacz Grzegorz, Kaminski Kamil, Paluch Marian
Institute of Physics, University of Silesia ul. 75 Pułku Piechoty 1 41-500 Chorzów Poland
Silesian Center of Education and Interdisciplinary Research, University of Silesia ul. 75 Pulku Piechoty 1A 41-500 Chorzow Poland.
RSC Adv. 2020 Jun 5;10(36):21593-21601. doi: 10.1039/d0ra02246b. eCollection 2020 Jun 2.
In this work, we developed a fast, highly efficient, and environmentally friendly catalytic system for classical free-radical polymerization (FRP) utilizing a high-pressure (HP) approach. The application of HP for thermally-induced, bulk FRP of 1-vinyl-2-pyrrolidone (VP) allowed to eliminate the current limitation of ambient-pressure polymerization of 'l' monomer (LAM), characterized by the lack of temporal control yielding polymers of unacceptably large disperisites and poor result reproducibility. By a simple manipulation of thermodynamic conditions ( = 125-500 MPa, = 323-333 K) and reaction composition (two-component system: monomer and low content of thermoinitiator) well-defined poly(1-vinyl-2-pyrrolidone)s (PVP) in a wide range of molecular weights and low/moderate dispersities ( = 16.2-280.5 kg mol, = 1.27-1.45) have been produced. We have found that HP can act as an 'external' controlling factor that warrants the first-order polymerization kinetics for classical FRP, something that was possible so far only for reversible deactivation radical polymerization (RDRP) systems. Importantly, our synthetic strategy adopted for VP FRP enabled us to obtain polymers of very high in a very short time-frame (0.5 h). It has also been confirmed that VP bulk polymerization yields polymers with significantly lower glass transition temperatures ( ) and different solubility properties in comparison to macromolecules obtained during the solvent-assisted reaction.
在这项工作中，我们开发了一种快速、高效且环境友好的催化体系，用于经典自由基聚合（FRP），采用了高压（HP）方法。将高压应用于1-乙烯基-2-吡咯烷酮（VP）的热引发本体FRP，能够消除当前“l”单体（LAM）常压聚合的局限性，其特点是缺乏时间控制，导致聚合物分散度大得不可接受且结果重现性差。通过简单地调控热力学条件（压力 = 125 - 500 MPa，温度 = 323 - 333 K）和反应组成（双组分体系：单体和低含量的热引发剂），制备出了分子量范围宽且分散度低/中等（Mn = 16.2 - 280.5 kg/mol，Đ = 1.27 - 1.45）的规整聚（1-乙烯基-2-吡咯烷酮）（PVP）。我们发现高压可以作为一个“外部”控制因素，保证经典FRP的一级聚合动力学，而这在迄今为止仅可逆失活自由基聚合（RDRP）体系中才有可能实现。重要的是，我们用于VP FRP的合成策略使我们能够在非常短的时间内（0.5小时）获得非常高Mn的聚合物。还证实了与溶剂辅助反应中获得的大分子相比，VP本体聚合得到的聚合物玻璃化转变温度（Tg）显著更低，且溶解性不同。
