羧甲基壳聚糖/明胶共混膜的结构表征与吸湿保湿性

壳聚糖通过羧甲基化得到水溶性N，O-羧甲基壳聚糖，并将其配制成4Wt％水溶液，与4Wt％明胶水溶液共混，成功制得了羧甲基壳聚糖／明胶共混膜。采用红外光谱、x射线衍射、扫描电镜对共混膜进行结构表征，结果表明，共混膜中羧甲基壳聚糖和明胶分子间存在着较强的相互作用及良好的相容性。通过共混膜的力学性能测试，发现当羧甲基壳聚糖含量为20％时，共混膜的抗张强度达到最大值(75MPa)，分别比单独的羧甲基壳聚糖(45MPa)和明胶(43MPa)提高了66．7％和74％。经过吸湿和保湿性能测试，发现当羧甲基壳聚糖含量为80％时，吸湿率和保湿率分别为33．4％和69．2％，比单独的明胶膜分别提高了1．8倍和2．1倍。     

INTROMISSION OF WATER-REPELLENT AND HYDROSCOPIC PROPERTIES SIMULTANEOUSLY TO PP BY PLASMA DISCHARGE METHOD

Plasma-induced surface graft copolymerization of acrylic acid on polypropylene non-woven fabric (PP-g-AA) and polypropylene membrane were reported. The extents of grafting were controlled by the plasma and polymerization condition. Hexadecyltrimethyl ammonium bromide was then coupled with the carboxyl group of PP-g-AA to obtain a polyion complex (PIC). At last, CF4 plasma was used to give PICs hydrophobic property. The moisture regain and water-repellency of the processed PICs was investigated. The surfaces were characterized using ATR FT-IR and XPS. The result indicates that the products have very high ability to adsorb moisture, even better than cotton fiber. At the same time, the products show excellent hydrophobic property, which can‘t be wetted by those reagents whose surface tensions were higher than 327mN/m.     

低分子量N-羧丁酰壳聚糖的合成及其吸湿保湿性

低分子量N-羧丁酰壳聚糖的合成及其吸湿保湿性;低分子量壳聚糖;低分子量N-羧丁酰壳聚糖;吸湿性;保湿性     

壳聚糖季铵化衍生物的吸湿性与保湿性

壳聚糖季铵化衍生物的吸湿性与保湿性许晨，卢灿辉（福建师范大学高分子研究所福州３５０００７）关键词壳聚糖季铵盐，壳聚糖衍生物，吸湿性，保湿性壳聚糖是从虾、蟹等废弃甲壳中提取得到的一种生物活性物质［１，２］，由于其特有的直链聚阳离子结构，成膜附于角蛋白与...     

羧甲基壳聚糖的取代度及保湿性

吸湿性;分子量;羧甲基壳聚糖的取代度及保湿性     

基于TD-NMR的PMMA木塑复合材吸湿和吸水研究

本研究采用时域核磁共振(TD-NMR)技术探究聚甲基丙烯酸甲酯(PMMA)木塑复合材在吸湿与吸水过程中水分的状态和自旋-自旋弛豫(T2)特征.并比较PMMA木塑复合材的阻湿率和拒水率,分析PMMA木塑复合材的阻湿和防水性能与原理.研究对象为浸渍甲基丙烯酸甲酯(MMA)单体聚合生成的PMMA木塑复合材.首先对绝干的PMMA木塑复合材进行核磁共振T2检测,然后分别进行吸湿和吸水实验,并每隔一段时间测定试件质量及其T2信号量.结果表明：PMMA木塑复合材的吸湿率和吸水率低于未处理材,具有良好的阻湿和防水性能,且MMA浸渍浓度为100%,浸渍时间为24 h时,在温度为(40±0.2)℃相对湿度为(96.4±0.4)%恒温恒湿环境下木塑复合材吸湿率低于15%,常温下吸水试件的吸水率低于30%.PMMA木塑复合材的吸湿率和吸水率明显降低,T2峰面积也逐渐减小.这说明木塑复合材内部的PMMA起到了防止水分进入的作用.     

淀粉糖苷表面活性剂的吸湿保湿性能研究

以马铃薯淀粉为糖源,利用转糖苷法合成淀粉糖苷表面活性剂,用重量法测定其吸湿性和保湿性,并与甘油、山梨醇、聚乙二醇、木糖醇、烷基多苷进行比较。结果表明,在30℃,相对湿度43%和相对湿度81%环境条件下,制得的淀粉糖苷表面活性剂的保湿性优于对比试样,72h后保湿率均在70%以上;其吸湿性仅次于甘油,72h后吸湿率达到50%。     

大气气溶胶吸湿性及其对环境的影响

吸湿性是气溶胶重要的物理化学特性,不仅会影响气溶胶的生命周期和大气行为,还会对大气环境、气候和人体健康产生重要影响。本文简要介绍了气溶胶吸湿参数和热力学模型,对粒径、化学组分以及多组分共存等因素对气溶胶吸湿性的影响进行分析,进一步总结了城市、农村森林和海洋极地等不同区域气溶胶吸湿观测结果。吸湿增长因子g(RH)、散射吸湿增长因子f(RH)和吸湿性参数κ等常用吸湿参数可以衡量气溶胶的吸湿能力;Zdanovskii-Stokes-Robinson(ZSR)混合定律和各种热力学模型能预测不同化学成分气溶胶的吸湿能力,是研究多组分混合气溶胶和气相平衡的重要工具。粒径、化学组分和混合状态影响气溶胶的吸湿性,如气溶胶g(RH)、潮解点或风化点的改变。由于排放源和环境条件的不同,城市、农村、森林、海洋、极地地区气溶胶粒径分布、化学组分和混合状态具有差异,气溶胶吸湿性不同。气溶胶吸湿性直接影响气溶胶含水量和相态,改变气溶胶的大气化学过程、老化过程和大气寿命,还影响环境能见度、辐射效应和在人体内的沉积位置和毒性。通过总结吸湿参数、理论模型、实验室研究、外场观测和环境影响等多方面的最新研究成果,以期为未来的吸湿研究提供参考和借鉴。     

含联苯结构的环氧树脂固化性能的研究

以3,3′,5,5′-四甲基联苯二酚为单体,合成了一种含联苯结构的环氧树脂.用DDM和DDS为固化剂对环氧树脂的固化性能进行了研究,发现与双酚A型环氧树脂相比,含有联苯结构的环氧树脂具有更好的耐热性,同时在耐湿性方面也有很大改进.     

Effect of mixing structure on the hygroscopic behavior of ultrafine ammonium sulfate particles mixed with succinic acid and levoglucosan

Understanding the interactions between water and atmospheric aerosols is critical for estimating their impact on the radiation budget and cloud formation. The hygroscopic behavior of ultrafine(100 nm)ammonium sulfate particles internally mixed with either succinic acid〔slightly soluble) or levoglucosan(soluble) in different mixing structures(core-shell vs. well-mixed) were measured using a hygroscopicity tandem differential mobility analyzer(HTDMA). During the hydration process(6-92% relative humidity(RH)), the size of core-shell particles(ammonium sulfate and succinic acid) remained unchanged until a s|ow increase in particle size occurred at 79% RH; however, an abrupt increase in size(i.e., a clear deliquescence) was observed at ~72% RH for well-mixed particles with a similar volume fraction to the core-shell particles(80:20 by volume). This increase might occur because the shell hindered the complete dissolution of the core-shell particles below 92% RH. The onset RH value was lower for the ammonium sulfate/levoglucosan core-shell particles than the ammonium sulfate/succinic acid core-shell particles due to levoglucosan's higher solubility relative to succinic acid. The growth factor(GF) of the core-shell particles was lower than that of the well-mixed particles, while the GF of the ammonium sulfate/levoglucosan particles was higher than that of ammonium sulfate/succinic acid particles with the same volume fractions. As the volume fraction of the organic species increased, the GF decreased. The data suggest that the mixing structure is also important when determining hygroscopic behavior of the mixed particles.