正电子淹没寿命谱在聚苯乙烯中的应用

The application of positron annihilation lifetime spectroscopy in polystyrene

采用自由基聚合方法合成了3个不同分子量的聚苯乙烯,进而用正电子淹没寿命谱(PALS)对这3个样品的拾获淹没寿命τ3及其淹没强度I3进行了研究。实验结果表明,常温下聚苯乙烯的拾获淹没寿命τ3对分子量没有依赖性,但分子量及极性基团对其淹没强度I3有着显著的影响。

Three polystyrenes with different molecular weight were synthesized by free radical polymerization, then positron annihilation lifetime spectroscopy （PALS） and Doppler broadening （DB） were adopted to detect the variations of lifetime τ3 and intensity τ3 of o-postironium. The results showed at room temperature, there was no molecular weight dependence of τ3, in contrary, the effects of molecular weight and polar group on τ3 were observably.