NIPAAm系共聚温敏凝胶的溶胀与释药性能

以N-异丙基丙烯酰胺(NIPAAm)系共聚凝胶为研究对象,通过引入亲水单体丙烯酰胺(AAm)和疏水单体甲基丙烯酸丁酯(BMA)制备PNIPAAm,P(NIPAAm-co-AAm)和P(NIPAAm-co-BMA)3种具有不同亲水性的共聚凝胶,研究NIPAAm系共聚凝胶对亲水性不同的2种模型药物的载药与释药行为。研究结果表明:NIPAAm系共聚凝胶呈现热缩温敏特性,在相转变温度(LCST)以下,随着凝胶亲水性的增强,凝胶的LCST升高,平衡溶胀比和初始溶胀速率增大;亲水性药物水杨酸钠的载药率提高,而增强凝胶的疏水性则有利于提高水杨酸的载药率;水杨酸和水杨酸钠的初始释药速率均增大,水杨酸钠初始释药速率明显大于水杨酸初始释药速率。对于亲水性相对较弱的水杨酸,高温下的平衡释药率明显小于低温下的平衡释药率,而对亲水性较强的水杨酸钠,PNIPAm共聚载药凝胶高温和低温平衡释药率相差不大;在温度低于LCST时,3种凝胶对于水杨酸的平衡释药率相差很大,而对于水杨酸钠的平衡释药率均为100%。     

水性聚氨酯的合成及改性

介绍了水性聚氨酯的各种合成方式,分析了其各种合成方式的优缺点,介绍了改性水性聚氨酯的几种最常用的改性方法,介绍了环氧树脂改性、有机硅改性、丙烯酸酯改性、纳米材料改性等不同改性技术的特点和制备方法并对改性技术的进一步发展作了展望。     

新型环氧类扩链剂合成

通过悬浮聚合的方法,将苯乙烯与甲基丙烯酸缩水甘油酯共聚,制备了一种新型的环氧类扩链剂.通过红外光谱法确定了产品的分子结构,热分析结果表明苯乙烯-甲基丙烯酸缩水甘油酯具有较好的热稳定性.环氧当量测定及粘度测定结果表明新型环氧类扩链剂应用性能与巴斯夫公司市售的环氧类扩链剂4360S以及4370S基本相同,但在经济性方面明显优于以上两种产品,表明所制备的环氧类扩链剂具有良好的市场前景及市场竞争力.     

某旧住宅楼阳台新修塑料地漏时防渗漏处理

介绍了在旧混凝土-新混凝土-塑料地漏的接合面和塑料地漏附近的楼板面涂敷环氧胶粘剂的方法来防止某旧住宅楼阳台新修塑料地漏时出现渗漏.实践表明:该法简便,易于工程实践,效果良好.     

水溶性环氧底漆的工艺及推广应用

通过ＭＩＬ－Ｐ－８５５８２Ｂ水溶性环氧底漆在Ｓ－９２尾斜梁铝合金、复合材料零部件上的应用，介绍了水深性环氧底漆的工艺及推广应用。     

浅析用奥氏气体分析仪测定煤气中的可燃组分

主要阐述了用奥氏气体分析仪测定煤气中可燃组分的分析方法，并推导出了煤气中H2和CH4含量的计算公式。     

木瓜蛋白酶的研究进展

木瓜蛋白酶是一类巯基蛋白酶，大量存在于木瓜乳汁中。对其组成成分、结构、制备、及在食品上的应用等方面的研究进展进行了综述。     

Adhesion of PBO Fiber in Epoxy Composites

The high mechanical and thermal performance of poly p-phenylene- 2, 6-benzobisoxazole ( PBO ) fiber provides great potential applications as reinforcement fibers for composites. A composite of PBO fiber and epoxy resin has excellent electrical insulation properties, therefore, it is considered to be the best choice for the reinforcement in high magnetic field coils for pulsed magnetic fields up to 100 T.However, poor adhesion between PBO fiber and matrix is found because of the chemically inactive and/or relatively smooth surface of the reinforcement fiber preventing efficient chemical bonding in the interface, which is a challenging issue to improve mechanical properties. Here, we report the surface modification of PBO fibers by ultraviolet (UV)irradiation, O2 and NH3 plasma, as well as acidic treatments. The interfacial adhesion strength values of all the treatments show the similar level as determined for aramid fibers by pull-out tests, a significant impact on fibermatrix-adhesion was not achieved. The surface free energy and roughness are increased for both sized and extracted fibers after plasma treatments together with maleic anhydride grafting. The sized fiber shows marginal improvement in adhesion strength and no change in fiber tensile strength because of the barrier effect of the finish.For the extracted fiber, different surface treatments either show no apparent effect or cause reduction in adhesion strength. Atomic force microscopy (AFM) topography analysis of the fracture surfaces proved adhesive failure at the fiber surface. The fiber surface roughness is increased and more surface flaws are induced, which could result in coarse interface structures when the treated fiber surface has no adequate wetting and functional groups. The adhesion failure is further confirmed by similar adhesion strength and compression shear strength values when the fiber was embedded in various epoxy resins with different temperature behavior. The tensile strength of fiber is sensitive to surface treatment conditions as revealed by a bimodal Weibull statistical distribution analysis. Considerable strength reduction occurred, particularly for cases of acidic and plasma treatments, while UV irradiation shows the better ability to retain fiber strength.     

水性聚氨酯的合成及成膜性分析

文采用HDI、聚环氧丙烷二醇、二羟甲基丙酸和封端剂乙二醇等为原料通过预聚法合成水性聚氨酯,并对其成膜性进行了力学分析.通过比较,最佳制备工艺:在40℃时向聚环氧丙烷二醇中缓慢加入HDI,80℃预聚1h,加催化剂再反应1h降温至75℃,加DMPA反应2h, 再封端反应1h,降温至35～40℃加入TEA乳化30min.交联剂相对含量的提高,可以提高聚氨酯膜的强度和韧性.     

玻璃鳞片胶泥在煤气管道中的应用

介绍了呋喃树脂、环氧改性糠醇树脂的性能、反应机理，以及玻璃鳞片的规格与用量，惰性填科等对涂膜耐化学性、施工性的影响。通过试验研制出玻璃鳞片胶泥，成功地应用于首钢搬迁工程的煤气管道中，有效地保护了管道，提高了使用寿命。