间规1,2-聚丁二烯结晶结构研究

以间规1,2-聚丁二烯(s-PB)为研究对象,通过原位同步辐射小角X射线散射(SR-SAXS)和广角X射线衍射(WAXD)研究其结晶结构的变化过程.SR-SAXS曲线中存在明显的散射峰,表明在等温结晶过程中形成有序结晶结构;在等温结晶后间规1,2-聚丁二烯的片晶厚度、微晶尺寸均正比于1/Tc∞-T,根据高分子结晶中介相机理可以做出合理的解释.

STUDIES ON CRYSTALLINE STRUCTURE OF SYNDIOTACTIC 1,2-POLYBUTADIENE

The in situ crystallization kinetics of syndiotactic 1,2-polybutadiene (s-PB) from melt has been investigated by synchrotron radiation small-angle X-ray scattering (SR-SAXS) and wide-angle X-ray diffraction (WAXD).The structure evolutions during the isothermal crystallization of s-PB crystallized at different temperatures have been observed.The results obtained from the scattering peaks in the SR-SAXS curves indicated the development of crystalline structure parameters including long period and lamellar thickness in the isothermal process.The calculated detail information about structure parameters according to the one dimensional electron intensity correction function showed that the long period decreased gradually along with time because the thickness of amorphous layers reduced significantly as the lamellar thickness remained unchanged.The final structures of s-PB about the lamellar thickness and the crystallite size were obtained from SAXS and WAXD,respectively.The line widths were measured for s-PB by WAXD for the selected L110 refection to determine the crystallite size according to Scherrer equation.The lamellar thickness and semicrystallite size were directly proportional to 1/T∞c-T,which can be explained by the mesomorphic phase theory on polymer crystallization.