采用Raman光谱研究硅烷接枝LLDPE的结晶结构

采用傅里叶变换红外光谱(FTIR)和Raman光谱表征了硅烷接枝线型低密度聚乙烯(LLDPE)的结晶结构。用FTIR和Raman光谱上硅烷特征峰与LLDPE亚甲基峰的强度比,可相对比较硅烷接枝LLDPE的接枝率,随着硅烷用量的增加,由FTIR计算的吸光比从0.96增至2.62,由Raman光谱计算的强度比从11.53增至14．00,两者的变化趋势相同。Raman光谱分析还表明,随着硅烷用量的增加,硅烷接枝聚乙烯的结晶相质量分数由57．58％降至46．99％,非晶相质量分数由11．58％升至16．52％,中间相质量分数从30．84％升至36．48％。

Study on crystallization of silane grafted LLDPE by Raman spectroscopy

The crystal structure of silane grafted linear low density polyethylene (LLDPE) was characterized by Fourier transform infrared spectroscopy (FTIR) and Laser Raman Spectroscopy. The graft ratio of LLDPE grafted by silane could be compared relatively based on the intensity ratio of characteristic peaks of silane to methy-lene peak of LLDPE in FTIR and Raman spectrum. As the silane content increased, the absorption ratio calculated in terms of FTIR spectrum rose from 0.96 to 2.62 and the same ratio figured out in accordance with Raman spectrum went up from 11.53 to 14.00, showing the identical tendency of variation in the respective calculation. In addition, the analysis by Raman spectroscopy further revealed that with increasing silane dosage, the mass fraction of crystal phase in silane grafted LLDPE lowered from 57.58% to 46.99%, whereas the mass fraction of amorphous phase and mesophase augmented from 11.58% to 16.52% and from 30.84% to 36.48%, respectively.