Preparation and Characterization of Carboxymethyl Chitosan and β-Cyclodextrin Microspheres by Spray Drying

Three kinds of carboxymethyl chitosan/β-cyclodextrin microspheres loaded with theophylline were prepared by spray drying intended for pulmonary delivery. Mucociliotoxicity, permeation rate, and drug release characteristics of the product were investigated. The microspheres obtained by spray drying were found to be spherical with smooth or wrinkled surfaces. The mean particle size was between 3.39 and 6.06 µm. The microspheres demonstrated high product yield (43.7-50.2%), high drug loading (13.7-38.1%), and high encapsulation efficiency (86.9-92.8%). FT-IR indicated that there were interactions of theophylline with carboxymethyl chitosan matrix. Further studies on mucociliotoxicity and permeation confirmed that microspheres had better adaptability and high permeation rate. In vitro drug release from the microspheres was not related to the drug/polymer ratios.     

Study on phase behavior–impact strength relationship of unsaturated polyester/polyurethane hybrid polymer network

The phase behavior of a hybrid polymer network (HPN) composed of poly[(propylene glycol maleate)-co-(propylene glycol phthalate)] crosslinked with styrene and polyester–urethane crosslinked with methylene-bis-ortho-chloroaniline was examined. The correlation between phase separation and impact strength of the HPNs is discussed. The composition of HPNs has an effect on their properties.     

马来酸酐接枝聚丙烯增容聚丙烯/碳酸钙复合物力学性能与增容机理

用在50L固相接枝反应器中合成的马来酸酐接枝聚丙烯(PP-g-MAH)作界面改性剂，制备了马来酸酐接枝聚丙烯／聚丙烯／碳酸钙(i-PP／PP-g-MAH／CaCO3)复合材料。研究了i-PP／PP-g-MAH／CaCO3复合材料的力学性能和增容机理。结果表明，PP-g-MAH对i-PP／CaCO3复合物的缺口冲击强度、弯曲强度和拉伸强度均有提高；PP-g-MAH与CaCO3反应形成PP-g-MAH的钙盐，实现反应性增容。     

基于测量系统分析(MSA)的实验仪器设备测评

引入测量系统分析(MAS)技术,对实验仪器设备进行测评分析,判断仪器是否合格,保障了仪器设备的精确性,并以实验室四架天平为例,检验了此方法的可行性。     

我国重液蜡生产及市场前景

介绍了国内重液蜡生产现状和市场情况 ,阐述了异丙醇 -尿素脱蜡优于分子筛脱蜡工艺的几个特点 ,并介绍了重液蜡在塑料业、洗涤业、皮革业和微生物方面的发展方向。