丙炔基双酚A醚硼聚合物热解过程的ReaxFF分子动力学模拟

聚合物的热解过程涉及的化学反应较为复杂,难以通过测试表征的手段深入探究其机理。本研究在实验表征的基础上,结合ReaxFF分子动力学(ReaxFF-MD)模拟方法,研究了丙炔基双酚A醚硼聚合物(PB)的热解过程。通过观察升温过程中PB的结构变化,可得到其热解过程中的断键顺序。此外,采用ReaxFF-MD模拟,其研究结果不仅验证了实验中热重-红外光谱联用(TG-FTIR)分析所得的PB热解生成小分子的主要组成为CH₄、H₂O、H₂ 和 CO,并且通过追踪上述小分子的生成过程可得到其主要的生成途径。以上研究结果表明,ReaxFF-MD模拟方法不仅有助于理解PB聚合物的热解机理,直观地反映出其热解产物生成途径,而且对聚合物耐热性能的研究有所借鉴。

Molecular dynamics simulations of thermal pyrolysis of novel dipropargyl ether of bisphenol A based boron-containing polymer

It is still a challenge to elucidate the dominant reaction pathways of pyrolysis of polymer via utilizing experimental analysis alone because pyrolysis of polymer involves a number of complicated reactions. A complementary way to investigate pyrolysis of polymer is possible via combinating computer simulation with conventional experimental characterization. In this paper, ReaxFF molecular dynamics(ReaxFF-MD)simulations were used to clarify the pyrolysis process of a dipropargyl ether of bisphenol A based boron-containing polymer(PB). The results from ReaxFF-MD simulation were then compared with the data obtained from experiments. The order of the break of chemical bond in the PB thermoset was obtained by observing the structural changes during cook-off simulation. The main small molecule products found in the simulation included CH₄, H₂O, H₂ and CO. In addition, typical mechanisms for the formation of small molecules were observed via simulating and tracking their generation processes. This ReaxFF-MD simulation complemented experimental characterization of PB thermoset pyrolysis and provided detail predictions of evolution of pyrolyzed products at the atomistic level.