羧甲基甲壳素与醋酸乙烯酯接枝共聚反应研究

以过硫酸铵为引发剂,合成了醋酸乙烯酯接枝羧甲基甲壳素共聚物,采用红外光谱对接枝共聚产物进行了表征。考察了溶剂用量、反应温度、反应时间、引发剂用量、单体用量等因素对反应接枝率和接枝效率的影响,获得了最佳反应条件。结果表明：羧甲基甲壳素0．4g,溶剂水50．0mL,醋酸乙烯酯1．5g,过硫酸铵60．0mg,在70℃反应3．0h时接枝效率最高,可达65．1％。接枝共聚改性反应可以扩展羧甲基甲壳素的应用价值。     

过硫酸钾引发羧甲基甲壳素和丙烯酸钾溶液接枝聚合

以过硫酸钾为引发剂,水为介质,制备了羧甲基甲壳素接枝丙烯酸钾共聚物,讨论了反应温度、反应时间、引发剂用量、单体用量对接枝率的影响,获得了最佳反应条件。结果表明：在含羧甲基甲壳素0．3g的30．0mL水溶液中,加入过硫酸钾50．0mg,丙烯酸钾水溶液8．0mL,于60℃反应120min时接枝率最高,达305．1％。接枝共聚物具有水溶性。接枝共聚改性反应可以扩展羧甲基甲壳素的应用价值。     

羧甲基甲壳素接枝丙烯酸丁酯共聚物的制备及水溶性

制备了羧甲基甲壳素接枝丙烯酸丁酯共聚物,讨论了反应温度、时间、引发剂用量、溶剂用量、单体用量对接枝反应的影响。最佳反应条件为:羧甲基甲壳素0.3g,溶剂水30mL,引发剂50mg,单体1.2g,反应温度60℃,反应时间3.5h。用红外光谱对接枝产物进行了表征,考察了不同接枝率的产物在10种常见溶剂中的溶解性,结果表明不同接枝率的接枝产物都有水溶性。     

丙烯酰氧基螺噁嗪接枝羧甲基甲壳素反应条件的研究

采用接枝共聚法合成了一种具有螺噁嗪侧基的羧甲基甲壳素水溶性衍生物。讨论了反应温度、反应时间、引发剂用量、溶剂用量、单体用量对丙烯酰氧基螺噁嗪接枝羧甲基甲壳素反应的影响。接枝效率最高时反应条件为:羧甲基甲壳素0.4 g,溶剂水50.0 mL,引发剂0.35 mmol,单体3.0 mmol,反应温度70℃,反应时间4.0 h,接枝率为65.0%,接枝效率为25.2%。     

一种光致变色偶氮染料接枝羧甲基甲壳素高聚物的合成

以水为介质、过硫酸铵为引发剂,采用接枝共聚法合成了一种具有光致变色偶氮侧基的羧甲基甲壳素衍生物,用红外光谱对其结构进行了表征.讨论了反应温度、反应时间、引发剂用量、溶剂用量、单体用量对接枝共聚反应的影响.确定最佳合成条件为:羧甲基甲壳素0.3 g、溶剂水30.0 mL、引发剂30.0 mg、偶氮单体0.90 g、反应温度70℃、反应时间4.0 h,此时接枝率为92.0%,接枝效率为30.7%.     

羧甲基甲壳素与丙烯酸钠溶液接枝共聚反应研究

以过硫酸铵为引发剂,制备了羧甲基甲壳素接枝丙烯酸钠共聚物,讨论了反应温度、反应时间、引发剂用量、单体用量对接枝率的影响。红外光谱分析说明接枝反应是由过硫酸铵和羧甲基甲壳素上存在的氨基组成的氧化还原引发体系引发的。     

丙烯腈接枝羧甲基甲壳素水溶性衍生物的制备和表征

以羧甲基甲壳素和丙烯腈为原料,制备了丙烯腈接枝羧甲基甲壳素衍生物,讨论了反应温度、反应时间、溶剂用量、引发剂用量、单体用量对接枝反应的影响。结果表明,最佳反应条件为:羧甲基甲壳素0.4 g,溶剂水40.0 mL,过硫酸铵50.0 mg,丙烯腈2.5 g,反应温度60℃,反应时间2 h。所制共聚产物具有水溶性,分析了产物具有水溶性的原因。     

过硫酸铵引发丙烯酸甲酯接枝羧甲基甲壳素共聚

以过硫酸铵为引发剂,制备了羧甲基甲壳素接枝丙烯酸甲酯共聚物,讨论了反应条件对接枝率和接枝效率的影响.确定最佳反应条件为:羧甲基甲壳素0.4 g,丙烯酸甲酯2.0 g,水50.0 mL,过硫酸铵60.0 mg,在50℃反应3.0 h.接枝共聚物具有水溶性.接枝反应是由过硫酸铵和羧甲基甲壳素上存在的氨基组成的氧化还原引发体系引发的.     

乙酸乙烯酯与PVC接枝共聚物的制备及其性能

以过氧化苯甲酰(BPO)为引发剂,通过接枝共聚反应制备了乙酸乙烯酯接枝PVC的共聚物,考察了脱氯时间,引发剂、分散剂和单体的用量,反应温度,接枝时间对接枝共聚的影响,以及单体用量对接枝共聚物吸油性能和压缩性能的影响。结果表明:PVC与乙酸乙烯酯适合的接枝共聚工艺条件为:PVC脱氯时间1 h,分散剂用量0.8 g,引发剂用量0.9 g,反应温度90℃,单体用量7 g,接枝时间2 h。     

羧甲基纤维素-丙烯酰胺接枝共聚的工艺条件研究

以羧甲基纤维素(CMC)为接枝底物,丙烯酰胺(AM)为接枝单体,过硫酸铵和亚硫酸氢钠为引发剂,N,N′-亚甲基双丙烯酰胺(MBAM)为交联剂,制备羧甲基纤维素-丙烯酰胺接枝共聚物。对CMC/AM质量比、MBAM用量、引发剂用量、反应温度、反应时间等因素对反应的影响进行了探讨。结果表明,聚合的最佳条件为:CMC/AM为6/1~7/1,交联剂MBAM为0.003 g,引发剂为单体质量的1%~2.5%,反应温度为45℃,反应时间为3~3.5 h。     

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。