交联壳聚糖吸附树脂的制备

文章用甲醛交联壳聚糖制备了一种新型的吸附树脂,探讨了几种反应因素对交联率的影响,并进行了树脂的表征。结果表明,甲醛交联壳聚糖的反应主要发生在壳聚糖分子的氨基和羟基上;当壳聚糖与甲醛的质量比为1∶5,体系反应温度为60℃,反应时间为1 h,搅拌速率为440 r/min,pH为10时,可制得成球性好,耐酸性强的壳聚糖基树脂吸附材料。     

微波交联壳聚糖树脂合成工艺条件对Pb~(2+)吸附量的影响

以壳聚糖为原料,合成了微波交联壳聚糖树脂。研究了乳化剂用量、聚乙二醇相对分子质量、交联反应时间等合成工艺条件对树脂及对Pb2+吸附量的影响。结果表明,当以聚乙二醇2000为致孔剂,0.12 g乳化剂,2 m L甲醛,5 m L环氧氯丙烷,交联反应t在20 min时,树脂对Pb2+具有较高的吸附量。     

缩水甘油基三乙基氯化铵交联壳聚糖的制备及性能

以环氧氯丙烷和三乙胺为原料合成了缩水甘油基三乙基氯化铵,并用其对壳聚糖进行了交联改性。产品结构经FT IR、HRTEM进行了表征;考察了反应时间、反应温度及pH值对壳聚糖交联取代度的影响;探讨了交联取代度对产品热稳定性和水溶性的影响。结果表明,缩水甘油基三乙基氯化铵成功地对壳聚糖进行了交联改性;pH≈7、反应温度90℃、反应时间14h时,交联壳聚糖的取代度最大可达93.4%;交联壳聚糖的热稳定性比壳聚糖有所降低,且随取代度的增大而下降;水溶率随取代度的增大而升高。     

交联壳聚糖树脂对阴离子染料吸附性能的研究

以甲醛-环氧氯丙烷为交联剂,采用反向悬浮法制备了交联壳聚糖树脂(CCTSR).研究了染料溶液初始浓度、时间、pH值和温度等因素对壳聚糖树脂吸附C.I.活性19、C.L活性蓝21、酸性橙II的影响,并探讨了交联壳聚糖树脂对3种阴离子染料的吸附规律.实验结果表明:适宜的酸性条件及较高的染液初始浓度有利于提高CCTSR对三种染料离子的吸附性能;而温度对染料吸附呈现不同的影响趋势.交联壳聚糖树脂对这3种染料的吸附符合Langmuir吸附等温式和Freundlich吸附等温式,吸附动力学模型可以用准二级速率方程来描述.     

球型Co2+印迹壳聚糖树脂的吸附特性及动力学研究

以Co2 和壳聚糖为原料,环氧氯丙烷和异丙醇为交联剂,制备了球形Co2 印迹壳聚糖树脂。研究了pH值、温度等因素对该印迹树脂吸附的影响及其吸附动力学。结果表明,pH值小于3.5时,印迹CTS树脂无吸附能力,pH值在3.5～6.0之间,印迹CTS树脂的吸附量随pH值升高而增大。印迹CTS树脂的吸附符合二级吸附动力学方程:t/Q=0.0077 0.0048 t。球形印迹壳聚糖树脂的吸附是以多分子层不均匀吸附模式为主,符合Freundlich方程。在30～90℃的温度范围内,树脂的吸附量随温度升高而增加,70℃时达到最大值,随后呈下降趋势。     

新型改性壳聚糖的制备及其对2,4-二氯苯酚的吸附

采用水杨醛与壳聚糖反应生成Schiff’s碱,再用NaBH4还原,环氧氯丙烷交联制备壳聚糖衍生物,用FTIR对改性壳聚糖进行表征,并用于2,4-二氯苯酚的吸附研究。测试了改性产物的溶解性能,考察了吸附时间、溶液pH值、酚的浓度以及改性剂用量等因素对氯酚吸附的影响。结果表明,水杨醛改性环氧氯丙烷交联壳聚糖不溶于水、酸和碱;在pH=7、吸附时间为2 h时,对2,4-二氯酚的吸附量为128.2 mg/g。     

木材用玉米淀粉基胶粘剂的制备

以氧化玉米淀粉为主要原料,采用环氧氯丙烷为交联剂,通过交联改性的手段,制备淀粉基木材胶粘剂。研究了环氧氯丙烷用量、反应温度、反应时间及pH值对产品性能的影响。研究结果表明,环氧氯丙烷的用量占物料总质量的4.0%,于50℃反应4 h,反应体系的pH值为10时制备出的木材胶粘剂综合性能较好,耐水性得到显著改善。     

壳聚糖水凝胶的制备及其对罗丹明B的吸附研究

在印染废水处理中,壳聚糖作为一种环保高分子材料广受关注。以壳聚糖为原料,通过交联N,N’-亚甲基双丙烯酰胺,制备了一种壳聚糖水凝胶,并通过红外光谱分析、热重分析等对其进行表征。以罗丹明模拟废水,从吸附时间、温度和pH值等多因素优化壳聚糖水凝胶的吸附条件。结果表明,壳聚糖水凝胶吸附罗丹明B的最佳条件为反应时间为60min、pH值为6、温度为40℃时,对罗丹明B的去除率可达到92.1%。     

交联羧甲基壳聚糖对铅离子的吸附性能研究

主要对交联羧甲基壳聚糖对Pb^2 的吸附作用进行了研究，探讨了交联度，反应时间，溶液的PH值，温度，Pb^2＋的初始浓度等因素对吸附性能的影响。实验结果表明，交联羧甲基壳聚糖在水溶液中不流失。对Pb^2 的吸附具有Langmuir的吸附特征，有附过程符合一级反应动力学过程，低温有利于吸附，当溶液PH值为5－6时，吸附性能最好，最大吸附量为230mg/g。EDTA是理想的脱附剂，洗脱后的树脂可重复作用。     

交联阳离子壳聚糖对活性艳红KE-3B的吸附行为研究

壳聚糖是天然可降解的生物高分子材料,本文以环氧氯丙烷交联的壳聚糖为原料,以自制备的阳离子化试剂2,3-环氧丙基三甲基氯化铵作为醚化剂,采用半干法合成了交联阳离子壳聚糖,取代度为0．18。本文在静态条件下,研究了交联阳离子壳聚糖对活性艳红KE-3B的吸附,探讨了交联阳离子壳聚糖吸附活性艳红KE-3B的最佳工艺条件。结果表明,交联阳离子壳聚糖对活洼艳红具有较好的吸附性能,吸附的最佳pH值为5—6,最佳吸附时间为20min,饱和吸附量为35．7mg／g,吸附率最大可达75．6％以上。     

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。