热塑性弹性体SIS和SBS的热降解行为研究

利用热重法研究了SBS（苯乙烯／丁二烯／苯乙烯热塑性弹性体）和SIS（苯乙烯／异戊二烯／苯乙烯热塑性弹性体）在N2气氛下以不同升温速率β时的热降解过程及动力学。结果表明，SIS的热降解过程分3步完成，SBS的热降解分2步完成，后者的热稳定性高于前者；SIS的热降解反应活化能为193．2kJ／mol，SBS的热降解属随机成核和随后生长过程控制机理，热降解反应的活化能为303．5kJ／mol。     

SIS-g-AN热降解性能的研究

采用热重分析法和差示热重分析法研究丙烯腈(AN)接枝热塑性弹性体SIS(SIS g AN)的热降解性能。结果得出,SIS g AN的平衡起始降解温度、平衡最大降解速率温度和平衡终止降解温度分别为659. 17, 713. 94 和740.05 K;热降解反应活化能为195.2 kJ·mol-1;热降解机理是Deceleration中的D3 降解机理;不同质量损失率下的热寿命与温度呈线性关系。     

不同分子结构SBS的热降解行为研究

采用热重分析法研究3种不同分子结构的苯乙烯-丁二烯-苯乙烯三嵌段共聚物(SBS)热降解行为。结果表明3种SBS的热降解过程都分为2个阶段,且星型结构4402的热降解温度最低。利用Kissinger和Flynn-Wall-Ozawa方法对SBS的热降解动力学进行研究,发现3种SBS的热降解活化能由大到小依次为1401,1301,4402。     

石油树脂/聚氨酯防水材料热性能研究

以聚氨酯预聚体为基料，以石油树脂为改性剂，制备了石油树脂／聚氨酯防水材料；分析了石油树脂／聚氨酯防水材料的热降解过程，研究了石油树脂／聚氨酯防水材料的热降解动力学。根据求得的热降解活化能讨论了石油树脂含量对防水材料热稳定性的影响。结果表明，石油树脂／聚氨酯防水材料的热降解分为两个阶段，起始平衡降解温度是231．04℃，热降解机理符合Freeman—Carroll假设，防水材料的热稳定性随着石油树脂用量的增大而有所降低。     

SBC供求矛盾有望缓解

SBC（苯乙烯-丁二烯共聚物）包括SBS（苯乙烯-丁二烯-苯乙烯嵌段共聚物）、SIS（苯乙烯-异戊二烯-苯乙烯嵌段共聚物）、SEBS（氢化SBS）、SEPS（氢化SIS）等。2006年全世界SBC的总生产能力为154．4万t，我国2006年SBC消费量超过50万t，而产量不足30万t。由于目前国内SBC的产能无法满足实际生产的需求，因而多家公司计划扩产或新建。台橡公司计划在南通市投资兴建5万t/a氢化SBS装置；     

石油发酵尼龙1313热降解性能的研究

利用热重分析和差示热重分析法研究了石油发酵尼龙1313在N2气流中以不同速率升温时的热降解过程及其动力学，发现尼龙1313的热降解过程为一步反应；随着升温速率的增大，降解温度线性升高，降解率则变化不大；分别用Coats-Redfem方法、Ozawa方法和Friedman方法进行了反应动力学处理，确定尼龙1313的表观降解反应级数为1．0,反应活化能为277．8kJ／mol左右。     

SIS-g-BMA热降解动力学研究

采用热重分析法和差示热重分析法研究苯乙烯-异戊二烯-苯乙烯三元嵌段共聚物(SIS)与甲基丙烯酸丁酯(BMA)的接枝共聚物(SIS-g-BMA)在氮气和氧气气氛中的热降解性能.结果表明,SIS-g-BMA在氮气气氛中第1步热降解温度范围为398～739 K,质量损失率为93.7%,最大热降解速率温度为658.2 K,第2步热降解温度范围为739～945 K,质量损失率为6.3%,平均活化能为176.1 kJ·mol-1;在氧气气氛中第1步热降解温度范围为459～719K,质量损失率为76.8%,第2步热降解温度范围为719～776 K,质量损失率为23.2%,最大热降解速率温度为735.0K,平均活化能为51.75 kJ·kJ·mol-1.     

台橡SBC热塑弹性体品种多性能好

我国台湾省台橡股份有限公司是生产SBC热塑性弹性体最早的企业，品种很多，性能很好，产量很大。SBC（丁二烯／苯乙烯嵌段共聚物）是苯乙烯类热塑性弹性体（TPE），包括未充油／充油SBS、SEBS、SIS等类型，具体品种未充油SBS牌号有411／411P、3201／3201P、3202、4202、4230等；SEBS的牌号有3150、3151、3152、3154等；SIS的牌号有1307、2393等。可用于制备SBS装修胶、SBS喷胶、SBS压敏胶、热熔胶、热熔压敏胶、密封胶及沥青、塑料、橡胶改性等。     

嵌段共聚物的改性研究及其在胶黏剂中的应用

论述了嵌段共聚物SBS／SIS（苯乙烯-丁二烯-苯乙烯／苯乙烯-异戊二烯-苯乙烯）的结构、结构对性能的影响及其在胶黏剂中的应用概况,重点介绍了它们的各种改性方法、改性机理及其改性后的效果。将各种化学改性方法和共混改性方法结合起来运用,有条件时进一步使用电子束或紫外光改性,是其重要的发展趋势。     

金属铁离子对苯乙烯-丁二烯-苯乙烯嵌段共聚物热氧老化性能的影响（英文）

为了考察制备过程中产生的游离铁离子对苯乙烯-丁二烯-苯乙烯嵌段共聚物(SBS)热氧老化性能的影响,制备了不同铁含量的SBS试样,并采用差示扫描量热法、全反射傅里叶变换红外光谱及热空气加速老化实验方法分析了不同铁离子对SBS热氧老化过程的影响规律。结果表明,随着体系中铁离子含量的增加,SBS试样出现老化交联吸热峰的温度降低,且交联峰面积增大;随着热氧老化的进行,SBS中形成了含有羰基的酮和醛类结构,转化率呈"S"型趋势增加,且随着铁离子含量升高,SBS分子结构中亚甲基、乙烯基、1,4-双键的含量依次降低,转化率升高,热氧老化程度增大,说明铁离子加速SBS热氧老化的过程明显。推断其作用机理为在热氧氧化初期,铁离子引入的更多的氧首先进攻亚甲基上的α-H,产生游离自由基,并进一步攻击不饱和双键,从而引发SBS产生不同程度的交联和降解。     

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。