在1000~800 cm-1频率范围内,分别采用一维红外光谱法、二阶导数红外光谱法和四阶导数红外光谱法测定了聚丙烯的结构.研究发现:809 cm-1、841 cm-1、900 cm-1和998 cm-1频率处的四个红外吸收峰均归属于等规聚丙烯晶体红外吸收谱带(δcrystalline).进一步采用二维红外光谱法研究了温度对聚丙烯δcrystalline的影响.研究发现,随着测定温度的升高(30~120℃),聚丙烯分子中δcrystalline红外吸收强度变化快慢顺序为:998 cm-1>841 cm-1>900 cm-1>809 cm-1.此项研究显示出二维红外光谱技术在聚丙烯高分子材料热变性分析中的重大作用.

In the range from 1000~800 cm-1, the polypropylene molecular structure had been studied by one-dimensional infrared spectroscopy, second derivative infrared spectroscopy and fourth derivative infrared spectroscopy.The isotaetic polyprolene crystal band(δcrystalline) occurred respectively near 809 cm-1, 841 cm-1, 900 cm-1 and 998 cm-1.The δcrystalline was researched by two-dimensional infrared spectroscopy also.Two-dimensional infrared spectra of polypropylene were studied to determine the sequence of intensity changes.It had been found that the sequence of intensity changes was 998 cm-1 > 841 cm-1 >900 cm-1 >809 cm-1with the increase of temperature(30~120 ℃).The study demonstrated the key roles of two-dimensional infrared spectroscopy in the analysis of thermal denaturation of the polymer materials.