以正二十烷、 聚乙烯和乙丙橡胶等为原料经熔融挤出，制成正二十烷含量 10%~65%的共混切粒。以正十八烷微胶囊和聚乙烯为原料经熔融挤出， 制成微胶囊含量 10%~60%的共混切粒。采用差示扫描量热仪和熔融指数仪测试了多种组成切粒的相变性能和流动性能。切粒的热焓随相变材料含量的增高而增大，含65正二十烷的切粒的热焓为160 J/g左右，含有6 0 wt微胶囊的切粒的热焓为70 J /g左右。切粒的熔融指数随相变材料或相变材料微胶囊添加量的增高呈现指数增大或反S曲线的形式。

Microcapsules and nanocapsules containing n-octadecane with melamine-formaldehyde shell were fabricated by in situ polymerization. The effects of stirring rate, contents of emulsifier and contents of cyclohexane on diameters, morphology, phase change properties and thermal stabilities of the capsules were studied by using FT-IR, SEM, DSC and TG. The diameters of the microcapsules decreased with the increase of stirring rate, emulsifier content and cyclohexane content. The relationship between stirring rate and number-average diameters or weight-average diameters of the microcapsules is an exponent. The relationship between emulsifier content and number-average diameters or weight-average diameters of the microcapsules is an exponent, too. The diameters had less effects on the melting behaviour of microcapsules, however, they had significant effects on the crystallization behaviour. As the diameters of the microcapsules decreased, two crystallization peaks were observed from the DSC cooling curves. The ratio of the integrated area of the peak in the lower temperature increased with the decrease in diameters of microcapsules. The thermal stability of micro/nanocapsule rises with the increase of stirring rates and TA content. The cyclohexane content has no significantly effect on thermal stability of the nanocapsule.

The microcapsules comprising n-octadecane and nucleating agents encapsulated in melamine-formaldehyde resin shell with about 1µm in average diameter were prepared through in situ polymerization. The effects of nucleating agents, i.e. sodium chloride, 1-octadecnol and paraffin, on the crystallization properties, morphology and dispersibility of microcapsules were investigated using SEM, DSC and XRD. The super-cooling was prevented by adding about 6wt% sodium chloride to the emulsion, however, the microcapsules were worse dispersed and their surfaceswere rough. Adding approximately 9wt%1-octadecanol in corematerialwas found to preventmicrocapsules fromsuper-cooling, but the microcapsules were easily conglomerated and their surfaces were extraordinarily rough. Microcapsules with approximately 20wt% paraffin in core material were free from super-cooling, and paraffin had no influence on the morphology and dispersibility of microcapsules.

A series of microcapsulescontaining n-octadecane with a urea-melamine-formaldehyde copolymer shell were synthesized by insitu polymerization. The surface morphology, diameter, melting and crystallization properties, and thermal stability of the microcapsules were investigated by using FTIR, SEM, DSC, TGA and DTA. The diameters of the microcapsules are in the range of 0.2-5.6µm. The noctadecane contents in the micro-capsules are in the range of 65-78wt%. The mole ratio of urea-melamine has been found to have no effect on the melting temperature of the microcapsules. Two crystallization peaks on the DSC cooling curve have been observed. The thermal damage mechanisms are the lique-fied n-octadecane leaking from the microcapsule and breakage of the shell due to the mismatch of thermal expansion of the core and shell materials at high temperatures. The thermal stability of materials can be enhanced up to 10℃ by the copo-lymerization of urea, melamine and formaldehyde in a mole ratio 0.2:0.8:3. The thermal stability of 160℃ heat-treated microcapsules containing 8.8% cyclohexane can be further enhanced up to approxi-mately 37℃.

静电纺丝即是高聚物熔体或溶液在外加电场作用下连续生成直径在亚微米级的超细纤维过程。文中扼要地介绍了静电法超细纤维的生产原理、设备、生产过程及近几年来国内外静电纺丝的各种产品(主要包括聚环氧乙烷、聚酰胺、聚酯、聚乙炔、聚苯胺、聚氯乙烯、聚偏氟乙烯、聚碳酸酯、聚甲基丙烯酸甲酯等)；并指出了静电纺超细纤维新的应用领域(如过滤膜、复合材料增强体、防弹衣等)；最后对静电纺超细纤维未来的发展提出设想。