天然纤维及其改性技术在橡胶材料中的应用研究

秸秆纤维和纳米纤维素是天然纤维中的两种重要品种。介绍了秸秆纤维的物理和化学处理方法以及纳米纤维素的制备方法及其改性技术在橡胶材料中的应用情况,指出了其今后的发展方向。     

甘蔗渣纤维素的提取及纳米化改性应用研究进展

概述了纤维素的提取方法；综述了甘蔗渣纤维素的预处理方式(物理方法、化学方法、生物法以及混合改性);详细介绍了蔗渣纳米纤维素的制备方法，包括机械法、化学法、微生物法和混合法；对蔗渣纳米纤维素在食品、水处理、医药、复合材料领域的应用进行了总结。     

改性聚碳酸亚丙酯研究进展

对可降解塑料聚碳酸亚丙酯(PPC)进行改性是改善其力学性能和热学性能的有效方法.综述了近年来改性PPC的研究机理,介绍了PPC的合成机理和热降解机理,主要阐述了PPC物理改性和化学改性方法.物理方法主要包括碳纤维、碳酸钙、改性纳米二氧化硅、纳米粘土、纤维素、有机蒙脱土(OMMT)等材料与PPC进行共混改性,化学方法主要...     

纳米纤维素膜疏水化改性研究进展

近些年来,以纳米纤维素为原料制备出的柔性透明薄膜,因其优异的机械性能、可再生性、生物相容性等,在新型包装材料、透明电子元器件基底等领域展现出巨大的应用价值。然而在潮湿环境下,纳米纤维素膜如何维持高的机械性能,成为其在高附加值领域应用中一个重要又易被忽视的问题。先阐述了纳米纤维素膜以及天然亲水性对其隔绝和机械性能的影响,接着从化学改性、物理吸附、共混交联三种改性方法入手,综述了近些年来纳米纤维素膜疏水改性的研究与进展,以及不同改性方式对膜材料应用性能的影响。     

疏水化改性纳米纤维素的制备及应用研究进展

综述了疏水化改性纳米纤维素的研究进展,从表面吸附改性、对表面羟基化学改性和接枝共聚改性3个方面论述了对纳米纤维素的疏水化改性研究,介绍了疏水改性纳米纤维素及其衍生物在乳液和泡沫稳定方面以及在造纸、气凝胶和膜材料领域中的应用,并对其发展进行了展望,为其广泛应用提供了参考。     

原子转移自由基聚合法接枝改性纳米纤维素及其功能化应用

纳米纤维素不仅具有天然纤维素的基本结构和特性,还具有纳米粒子的独特性能,使其成为众多领域的研究热点。然而,由于纳米纤维素表面存在丰富的羟基,导致表面化学性质单一,需要对其进行化学改性拓宽应用领域。原子转移自由基聚合法(ATRP)能够对纳米纤维素表面进行接枝改性,从而赋予纳米纤维素多样化的功能特性,是纳米纤维素高值化应用的重要方法。本文首先总结了传统ATRP法以及四种新型ATRP法在纳米纤维素表面接枝改性中的应用进展;随后介绍了ATRP法在纳米纤维素端基接枝改性中的应用进展;然后分别介绍了ATRP改性的纳米纤维素接枝共聚物在纳米复合增强、智能响应、环保和生物医疗等领域的应用研究;最后总结了ATRP法改性纳米纤维素存在的难点,并展望了未来ATRP法在纳米纤维素接枝改性领域的发展趋势。     

面膜基布材料用纳米纤维素的制备研究进展

本文论述了一种低碳环保的可用作面膜基布材料的纳米纤维素的制备研究进展,分别介绍了植物纤维等天然纤维素制备纳米纤维素的化学、物理和生物制备方式,重点介绍了硫酸水解法和化学氧化法两种化学制备方式、高压均质和超声处理两种物理处理方法,以及生物酶制备纳米纤维素和微生物发酵生产纳米纤维素方法研究情况。     

纳米纤维素的疏水改性及应用研究进展

纳米纤维素作为一种性能优越的可再生纳米材料,应用前景极为广阔。然而,由于纳米纤维素结构上富含羟基,使其具有极强的亲水性,严重影响了纳米纤维素的疏水性能,并且在一定程度上限制了其在复合材料领域的应用。综述了纳米纤维素疏水改性的研究进展,从物理吸附、表面化学修饰（甲硅烷化、烷酰化、酯化等）、聚合物接枝共聚3个方面简述了目前应用较为广泛的疏水化改性方法,并对疏水纳米纤维素在包装材料、造纸、水净化等方面的应用现状进行了总结。最后对疏水改性纳米纤维素的未来发展进行了展望,旨在为疏水纳米纤维素的研究和应用提供参考。     

纤维素化学研究进展

为了研究当前纤维素化学发展现状,综述了纤维素超分子结构及其成因,介绍了纤维素自组装的结构模型,讨论了纤维素的多种原材料（细菌纤维素、人工化学合成纤维素、棉花、木材、禾草植物、韧皮纤维以及农业废弃物）,着重介绍了细菌纤维素的制备与商业用途以及人工化学合成纤维素,综述了目前纤维素化学研究的热门课题：选择性取代、新纤维素溶剂、纤维素的预处理、纤维素衍生物以及纤维素功能材料的发展现状、再生纤维的研究发展现状、纳米纤维素的制备与表面化学改性.选择适宜的原材料,对天然纤维素进行可控物理、化学结构设计,从而可以制备特殊功能的精细化工产品.纤维素化学是21世纪可持续发展的化学工程研究的重要课题之一.     

纳米纤维素晶须表面接枝及其液晶性能研究进展

作为一种新兴的纳米生物材料,纳米纤维素日益受到各界的广泛关注,对其进行表面接枝改性并开发新的功能是十分必要的。本文综述了纳米纤维素晶须表面接枝的技术及研究进展,主要介绍了传统自由基聚合、离子和开环聚合及活性自由基聚合技术,包括氮氧自由基调控活性聚合、原子转移自由基聚合、可逆加成-断裂链转移聚合、单电子转移活性自由基聚合,讨论了各种接枝聚合方法的适用范围和优缺点。简述了点击化学在纳米纤维素晶须表面接枝的应用。通过各种聚合方法改性得到的纳米纤维素晶须接枝共聚物往往具有一些特殊的功能,某些接枝共聚物在适当的溶剂中可以形成液晶态,本文重点介绍了接枝改性的纳米纤维素晶须的液晶性能及其形成机理和影响因素等。     

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。