壳聚糖及其衍生物与碘的络合物的抑菌性质研究

利用壳聚糖(CTS)、水杨醛改性壳聚糖(S-CTS)和还原水杨醛改性壳聚糖(RS-CTS)与碘以不同质量比制备络合物,通过碘量法测络合物的摩尔比,UV光谱和IR光谱对络合物进行了表征。考察了CTS和RS-CTS与碘络合物的抑菌性质。结果表明,壳聚糖及其衍生物与碘络合物摩尔比(壳聚糖及其衍生物结构单元与碘之比)分别为:n(CTS)∶n(I2)=1∶0.38,n(S-CTS)∶n(I2)=1∶0.85,n(RS-CTS)∶n(I2)=1∶0.73。CTS和RS-CTS与碘的络合物对金黄色葡萄球菌抑菌敏感度为高度敏感。     

絮凝剂CTS-GSH的合成及其除铬性能

以壳聚糖(CTS)、还原型谷胱甘肽(GSH)为反应物,通过水溶液聚合法制备了新型巯基化壳聚糖高分子絮凝剂壳聚糖?谷胱甘肽(CTS?GSH),采用单因素实验得到了最优的制备条件,并分析了产物的结构与表面微观性能. 结果表明,最优制备条件为质量比CTS:GSH 5:5、反应时间5 h、保护剂N-羟基丁二酰亚胺用量0.40 g、交联剂1-乙基-(3-二甲基氨基丙基)碳二亚胺盐酸盐用量0.25 g、反应体系pH 3.5. 壳聚糖与谷胱甘肽发生了酰胺化反应,所得CTS?GSH表面微观结构较好.     

环氧衍生物开环法制备壳聚糖季铵盐

采用异丙醇为溶剂,以壳聚糖(CTS)、2,3-环氧丙基三甲基氯化铵(GTA)为原料,用环氧衍生物开环法制备了壳聚糖季铵盐(HACC),通过单因素实验,考察了反应物摩尔比、反应时间、反应温度等因素对产物取代度的影响,结果表明,制备壳聚糖季铵盐的最优工艺条件为:n(CTS):n(GTA)=1∶4,壳聚糖相对分子质量(简称分子量,下同)3.2×105,碱化时间14h,预处理壳聚糖含水率20％,反应pH =7,反应温度75℃,反应时间8h.通过红外光谱、扫描电镜、热重分析对壳聚糖、壳聚糖季铵盐的结构、外观形貌、热稳定性进行了表征与分析,结果表明,壳聚糖季铵化改性以N取代为主,改性后外貌和粒度有了明显变化,并且热稳定性降低.     

高强度壳聚糖复合薄膜的制备研究现状

壳聚糖(CTS)是由甲壳素脱乙酰基的产物,完全脱乙酰化的壳聚糖的化学名称是(1,4)-2-氨基-2-脱氧-β-D-葡萄糖。是一种具有良好的生物相容性和溶解性的天然高分子化合物。国内外对壳聚糖基吸附材料的研究表明:壳聚糖、壳聚糖衍生物以及壳聚糖复合材料对重金属离子的吸附方面表现出良好的优势,本文综述了常见的高强度壳聚糖复合薄膜的制备方法。     

壳聚糖及其主要衍生物的研究进展

壳聚糖是一种天然的阳离子多糖，来源多样，造价低廉。它不仅是一种未被充分利用的资源，而且是一种在各个领域都很有潜力的新型功能材料。壳聚糖及其衍生物在医疗、工业、农业、日化、环保等领域发挥重要作用。根据国内外相关文献，对壳聚糖及其主要衍生物的制备方法、理化性质及具体应用的最新研究进展进行了综述。     

PSAFC-CTS絮凝剂的制备与絮凝特性研究

采用实验室自制聚硅酸氯化铝铁( PSAFC)与天然有机高分子壳聚糖(CTS)进行复配,制备成新型的无机-有机复合絮凝剂PSAFC -CTS.将该复合絮凝剂应用于蓝藻废水的处理,考察了 PSAFC与CTS的质量比、pH、反应温度及反应时间4个因素对其浊度去除率的影响,优化出最佳合成工艺条件为:m(PSAFC)∶m(CTS) =5∶1,pH为2.5,反应温度为70℃,反应时间为60 min.通过红外光谱和扫描电镜对PSAFC -CTS结构进行表征,结果表明,PSAFC与CTS在反应前后物质结构发生了变化,形成了相互交联成网状的三维新结构,生成了一种新型聚合配位化合物.     

氨基硫脲壳聚糖与碘的配合物抑菌性质研究

壳聚糖(CTS)与硫氰酸铵在乙醇中反应制得氨基硫脲壳聚糖(ATU-CTS)。制备ATU-CTS和碘的配合物(ATU-CTS-I2),用红外光谱和热重分析对CTS、ATU-CTS和ATU-CTS-I2进行表征。讨论了ATU-CTS与碘配合物的抑菌性质,结果表明ATU-CTS-I2对大肠杆菌和金黄色葡萄球菌抑菌敏感度为高度敏感。     

环氧衍生物开环法制备壳聚糖季铵盐的工艺研究

采用异丙醇为溶剂,以壳聚糖(CTS)、2,3-环氧丙基三甲基氯化铵(GTA)为原料,用环氧衍生物开环法制备了壳聚糖季铵盐(HACC).通过单因素实验,研究了反应物摩尔比、反应时间、反应温度等因素对产物取代度的影响.结果表明,制备壳聚糖季铵盐的最优工艺为:ncrs∶nGrA =1∶4,反应时间8h,反应温度75℃,反应pH值为7,碱化时间14h,壳聚糖分子量3.2×105,反应体系含水率20％.通过红外光谱、扫描电镜、热重仅对壳聚糖、壳聚糖季铵盐的结构、外观形貌以及热稳定性进行了表征与分析,结果表明壳聚糖季铵化改性以N-取代为主,改性后外貌和粒度有了明显变化,且热稳定性降低.     

改性壳聚糖加碘膜的制备与表征

壳聚糖(CTS)和水杨醛、环氧氯丙烷交联制备壳聚糖衍生物(RS-CTS-E),并制备相应衍生物的凝胶膜,将凝胶膜浸没在一定浓度碘乙醇溶液中,制备改性壳聚糖加碘膜(RS-CTS-E-I2),并对其进行了IR、SEM等表征。碘含量分析表明:改性壳聚糖凝胶膜对单质碘吸附量随碘乙醇溶液浓度增加而增大。碘吸附动力学结果表明其平衡吸附时间为6 h。抑菌性测试结果表明,w(I2)=19.05%时RS-CTS-E-I2膜对金黄色葡萄球菌抑菌环和大肠杆菌抑菌环的抑菌环直径分别为(31±1)mm和(30±1)mm,均为高度敏感。     

壳聚糖保鲜涂膜纳米SiO_x修饰工艺优化的研究

为了提高壳聚糖涂膜的力学性能和降低其透水率,实验先以十二烷基磺酸钠(SDS)活化纳米SiOx,随后将其加到壳聚糖乙酸溶液中,并用流延法制得分散比较均匀的壳聚糖纳米复合膜.此外采用二次回归旋转正交组合试验设计方法,优化了壳聚糖/纳米SiO(CTS/SiOx)复合涂膜的制备工艺条件,并通过红外(IR),X射线衍射(XRD)和电镜透射(TEM)手段对CTS/SiOx.复合涂膜的性能和结构进行袭征.优化结果表明,当壳聚糖(CTS)、活化纳米SiOx和单甘酯(Glyc)添加量分别为1.547 g、0.028 g和0.015 g时,CTS/SiOx,复合涂膜的性能达到最优,其拉伸强度和撕裂强度分别为54.85MPa和51.77kN·m-1,分别比未修饰壳聚糖单膜提高了63%和12%,而透水率却下降了73%.将制备的CTS/SiOx复合涂膜用于果蔬室温保鲜,保鲜质量和保鲜时间比对照组均有明显提高.     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.     

Methyl 2,4,6-decatrienoates Attract Stink Bugs and Tachinid Parasitoids

Halyomorpha halys (Stål) (Pentatomidae), called the brown marmorated stink bug (BMSB), is a newly invasive species in the eastern USA that is rapidly spreading from the original point of establishment in Allentown, PA. In its native range, the BMSB is reportedly attracted to methyl (E,E,Z)-2,4,6-decatrienoate, the male-produced pheromone of another pentatomid common in eastern Asia, Plautia stali Scott. In North America, Thyanta spp. are the only pentatomids known to produce methyl 2,4,6-decatrienoate [the (E,Z,Z)-isomer] as part of their pheromones. Methyl 2,4,6-decatrienoates were field-tested in Maryland to monitor the spread of the BMSB and to explore the possibility that Thyanta spp. are an alternate host for parasitic tachinid flies that use stink bug pheromones as host-finding kairomones. Here we report the first captures of adult and nymph BMSBs in traps baited with methyl (E,E,Z)-2,4,6-decatrienoate in central Maryland and present data verifying that the tachinid, Euclytia flava (Townsend), exploits methyl (E,Z,Z)-2,4,6-decatrienoate as a kairomone. We also report the unexpected finding that various isomers of methyl 2,4,6-decatrienoate attract Acrosternum hilare (Say), although this bug apparently does not produce methyl decatrienoates. Other stink bugs and tachinids native to North America were also attracted to methyl 2,4,6-decatrienoates. These data indicate there are Heteroptera in North America in addition to Thyanta spp. that probably use methyl 2,4,6-decatrienoates as pheromones. The evidence that some pentatomids exploit the pheromones of other true bugs as kairomones to find food or to congregate as a passive defense against tachinid parasitism is discussed.     

2007～2008年世界塑料工业进展

收集了2007年7月～2008年6月世界塑料工业的相关资料,介绍了2007～2008年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况.按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯·硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、不饱和聚酯树脂、环氧树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍.     

2005～2006年国外塑料工业进展

收集了2005年7月～2006年6月国外塑料工业的相关资料,介绍了2005—2006年国外塑料工业的发展情况。提供了世界塑料产量、消费量及全球各类树脂生产量以及各国塑料制品的进出口情况。作为对比,介绍了中国塑料的生产情况。按通用热塑性树脂（聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂）、工程塑料（聚酰胺、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚）、通用热固性树脂（酚醛、聚氨酯、不饱和树脂、环氧树脂）、特种工程塑料（聚苯硫醚、液晶聚合物、聚醚醚酮）的品种顺序,对树脂的产量、消费量、供需状况及合成工艺、产品开发、树脂品种的延伸及应用的扩展作了详细的介绍。