文章摘要
罗勇,徐玄之.分子链剪切技术制备超低分子量聚氧化乙烯[J].精细化工,2019,36(11):
分子链剪切技术制备超低分子量聚氧化乙烯
Preparation of Ultra-low Molecular Weight PEO by Molecular Chain Shearing Technology
投稿时间:2019-03-17  修订日期:2019-04-22
DOI:
中文关键词: 聚氧化乙烯  分子链剪切  超低分子量  紫外光
英文关键词: Polyethylene oxide  Molecular chain shearing  Ultralow molecular weight  Ultraviolet
基金项目:上海市科委青年科技启明星项目(19QB1402600)
作者单位E-mail
罗勇 上海化工研究院 real-luoyong@hotmail.com 
徐玄之 上海化工研究院  
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中文摘要:
      采用紫外光对黏均分子量为1.5×106的聚氧化乙烯(PEO)进行了分子链剪切,得到了分子量低于2.0×105的超低分子量PEO。考察了紫外光波长、功率、光源距离和反应温湿度等因素对PEO紫外剪切速率的影响,并对制备得到的不同低分子量PEO进行了结构分析和性能测试。结果表明:在试验装置上,紫外波长为185 nm,功率为75 W,光源距离为5 cm,环境温度为35 ℃,相对湿度为20%时,为较优反应条件,反应时间为2h、3 h、4 h和5 h可制备黏均分子量为1.5×105、8×104、5×104和4×104的超低分子量PEO。随着降解时间延长,PEO的分子量分布系数减小。PEO在紫外剪切过程中结构未发生明显改变,仅有少量甲酸酯生成。随着分子量减小,PEO的熔点降低,结晶度增加。
英文摘要:
      Ultra-low molecular weight polyethylene oxide (PEO) with viscosity-average molecular weight of less than 2.0×105 was obtained by molecular chain shearing under ultraviolet light with initial molecular weight of 1.5×106. The effects of ultraviolet wavelength, power, source distance, environmental tem-perature and humidity on the ultraviolet shear rate of PEO were studied. The structure and properties of PEO with different low molecular weight were characterized. The results show that ultra-low molecular weight PEO with viscous average molecular weight of 1.5×105、8×104、5×104 and 4×104 can be obtained in the test facility with the optimum reaction conditions with a UV wavelength of 185 nm, a power of 75 W, a light source distance of 5 cm, an ambient temperature of 35 C and a relative humidity of 20%. With the prolongation of shearing time, the molecular weight distribution coefficient of PEO decreases. The structure of PEO did not change significantly during ultraviolet shearing, only small amount of formate was formed. The melting point of PEO decreases and the crystallinity increases with the decrease of molecular weight.
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