利用改进后的光声压电技术对常用工程塑料的热扩散率进行了测量研究。介绍了改进后的光声压电理论模型，并搭建相应的实验系统。通过对参考样品铝和聚四氟乙烯的检测，完成了实验系统的校准和验证，并对8种常用工程塑料的热扩散率进行了测量，测量结果显示其热扩散率均小于0.4 mm2/s，具有良好的隔热性能。通过理论和实验研究结果表明，改进后的光声压电法可以准确测量工程塑料的热扩散率。

The thermal diffusivities of engineering plastics had been studied by the revised photoacoustic piezoelectric (PAPE) technique. Firstly, the revised PAPE method was proposed and the corresponding experimental system was set up. The experimental system was calibrated and tested by investigating the diffusivity of pure aluminum and polytetrafluoroethylene(PTFE). The thermal diffusivities of eight kinds of engineering plastics were measured by the revised PAPE method. The results showed that engineering plastics have excellent insulation properties and the diffusivities are under 0.4 mm2/s. The theoretical and experimental results showed that the revised PAPE method can be used to accurately measure the thermal diffusivity of engineering plastics.