基于分子动力学模拟的聚苯醚复合发泡体系研究OA

Polyphenylene oxide(PPO)has garnered significant interest in advanced applications such as 5G communica-tions and aerospace due to its exceptional thermal stability,mechanical strength,and low dielectric constant.However,its high melt viscosity and narrow foaming window have hindered the industrial scalability of PPO-based foams.To ad-dress this challenge,this study investigates a co-blowing agent system for PPO by integrating molecular dynamics simula-tions with experimental validation.The results demonstrated that the incorporation of ethanol as a co-blowing agent sig-nificantly strengthened the intermolecular interactions between the blowing agent and the PPO matrix while effectively lowering the glass transition temperature(Tg).As the ethanol content increases from 0 to 50 wt%,the interaction ener-gy between the blowing agent and PPO molecules decreases from-249.65 kJ/mol to-1 012.59 kJ/mol,and the Tg drops by approximately 60℃.Experimentally,this translates into a substantial improvement in gas solubility(from 4.05%to 18.72%)and a two-order-of-magnitude increase in the diffusion coefficient of the blowing agent within the polymer matrix.At 50℃wt%ethanol,the PPO foam achieved an expansion ratio of 21.0～12.75 times higher than that obtained with pure CO₂,and the optimal foaming temperature was reduced by 30℃.Moreover,the cellular morphology was well-controlled,with cell densities ranging from 2.5×10⁶ to 1.0×10⁷ cells/cm³.These findings underscore the crit-ical influence of molecular-scale interactions,governed by co-blowing agent composition,on macroscopic foaming perfor-mance.