不同分子量PEG对羟丙基甲基纤维素基新型避光膜材的多尺度结构和性能的影响研究

Study on the Effects of PEG with Different Molecular Weights on the Multiscale Structure and Properties of HPMC Based on New Photophobic Film

为了克服羟丙基甲基纤维素/磷酸二氢钠(HPMC/MSP)避光膜材延展性不足的问题,研究了不同分子量PEG对HPMC/MSP避光膜材的多尺度结构和性能的影响。研究表明,增塑剂仅影响了体系的自由水和氢键形成,并未影响其他官能团的振动,不同分子量PEG对体系自由水和氢键的影响作用不同。加入PEG后体系结晶度有一定变化,含有PEG1500和PEG4000的体系结晶度增加程度较大。PEG使体系大尺度分形结构的致密性降低,其中PEG4000、PEG6000和PEG8000使体系降低的程度较大。PEG800、PEG1500和PEG2000使膜材断面形貌变得相对光滑,PEG6000和PEG8000使膜材断面形貌相对平整。PEG的加入对膜材白度影响不大,其降低玻璃化转变温度的程度随PEG分子量的降低而增加。PEG使膜材拉伸强度和模量变化不大,断裂伸长率随PEG分子量的增加而增加,主要与其与体系的相容性越来越好有关。

In order to overcome the lack of ductility of HPMC/MSP photophobic film,the effects of PEG with different molecular weights on the multiscale structure and properties of HPMC/MSP film were studied.The results show that plasticizer could only affect the formation of free water and hydrogen bonds in the system,however it could not affect the vibration of other functional groups.PEG with different molecular weights has different effects on free water and hydrogen bonds in the system.The crystallinity of the system could be changed after PEG was added.The crystallinity of the system containing PEG1500 and PEG4000 could increase greatly.PEG could reduce the compactness of large-scale fractal structure for the system,and the using of PEG4000,PEG6000 and PEG8000 could reduce the system to a greater extent.PEG800,PEG1500 and PEG2000 make the cross-sectional morphology of the membrane relatively smooth,while PEG6000 and PEG8000 could make the cross-sectional morphology of the membrane relatively flat.The addition of PEG has little effect on the whiteness of the film,and its degree of lowering glass transition temperature could increase with the decrease of PEG molecular weight.PEG make little change in tensile strength and modulus of the film.The elongation at break could increase with the increase of molecular weight of PEG,which is mainly related to the better compatibility of the system.