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影响高分子质量聚氧化乙烯溶解速度的主要因素 |
Study of the Dissolution of Polyethylene Oxide with a High Molecular Weight in Water |
收稿日期: |
DOI:10.11980/j.issn.0254-508X.2016.12.005 |
关键词: 聚氧化乙烯 溶解速度 旋转黏度计 溶解动力学 |
Key Words:polyethylene oxide dissolution rate rotary viscometer dissolution kinetics |
基金项目:本课题得到了上海市普陀区科技创新项目研发人才专项(2014-Q002A)的资助。 |
作者 | 单位 | 孔 猛1,2,3 | 1.聚烯烃催化技术与高性能材料国家重点实验室,上海,200062;2.上海化工研究院,上海,200062;3.上海市聚烯烃催化技术重点实验室,上海,200062 | 康必显1,2,3 | 1.聚烯烃催化技术与高性能材料国家重点实验室,上海,200062;2.上海化工研究院,上海,200062;3.上海市聚烯烃催化技术重点实验室,上海,200062 | 罗 勇1,2,3,* | 1.聚烯烃催化技术与高性能材料国家重点实验室,上海,200062;2.上海化工研究院,上海,200062;3.上海市聚烯烃催化技术重点实验室,上海,200062 |
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摘要:本研究采用旋转黏度计,研究了聚氧化乙烯(PEO)的粒度、结晶度、溶解温度、溶液浓度、溶液pH值对其在水中溶解速度的影响。结果表明,PEO在水中的分散性和水分在PEO颗粒中的扩散速度是是影响PEO溶解速度的关键因素。大颗粒的PEO堆积密度大,能够快速在水相中分散,但水分子的扩散速度慢,因此大颗粒的PEO溶解速度慢;而在小颗粒PEO上虽然水分子扩散速度快,但因PEO堆积密度小,在水中的分散性较差,因而溶解速度慢。综合而言,40~60目的PEO溶解速度最快。PEO在酸性环境中会发生部分降解,因此在酸性溶液中,PEO的溶解速度快、黏度下降;而在碱性溶液中PEO比较稳定。示差扫描量热法(DSC)表征显示PEO是一种部分结晶性聚合物,研究表明在一定的结晶度范围内,溶解速度无明显变化。在溶解动力学实验中发现,PEO在水中的溶解过程属于零级反应,主要受扩散过程影响,溶解活化能为5.2 kJ/moL,属于易溶聚合物。 |
Abstract:As a kind of nonionic and water dissoluble polymer, polyethylene oxide (abr. as PEO) with a high molecular weight plays an important role in papermaking. In this paper, a rotary viscometer was employed to investigate the factors which affect the dissolution rate of PEO in water. It was uncovered that the dispersion of PEO in H2O and the diffusion of H2O in PEO particles affect the dissolution rate of PEO obviously. However, the crystalline degree of PEO affects slightly. Although PEO particles with a big size can disperse well in water, H2O molecules cannot permeate easily, as a consequence, it dissolves slowly. In contrast, PEO particles with a small size, H2O can go into particles and swell PEO easily. Comparatively, PEO with a particle size of 40~60 mesh dissolves fast. PEO solution is stable in a basic environment rather than in acid environment, because H+ promotes degradation of PEO. DSC results display that PEO is a partial crystallized polymer, and the dissolution rate of PEO changes less when the crystallinity at a range of 50%~58%. Moreover, dissolution kinetics of PEO shows the dissolution of PEO is a zero-order process, suggesting the dissolution of PEO in water is crucial, and the apparent dissolution activation energy is calculated as 5.2 kJ/mol. |
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