纳米碳酸钙/苯乙烯-丁二烯-苯乙烯嵌段共聚物复合改性沥青的制备及性能

采用纳米CaCO3和苯乙烯-丁二烯-苯乙烯嵌段共聚物（SBS）作为外加剂制备纳米CaCO3/SBS复合改性沥青。通过测试基本物理性能确定了外加剂的最佳掺量,通过流变性能测试、离析试验、荧光显微镜观察及热重分析等考察了沥青的性能及微观形貌。结果表明,两种外加剂复配的最佳比例为5%（质量分数,下同）的纳米CaCO3和4%的SBS;在纳米CaCO3改性沥青中掺加SBS后,复合改性沥青在不同温度下的黏度增大,高温抗车辙能力增强,低温性能得到明显改善,储存稳定性良好;纳米CaCO3分子、SBS分子和基质沥青分子三者具有良好的相容性,经复合改性后沥青的热稳定性增强。     

极性化苯乙烯-丁二烯-苯乙烯三嵌段共聚物的磺化改性及其纳米复合材料的制备

以浓硫酸和乙酸酐制得的乙酰硫酸酯为磺化剂,对极性化苯乙烯-丁二烯-苯乙烯三嵌段共聚物(PSBS)进行磺化改性,采用红外光谱表征了磺化PSBS(SPSBS),通过测定硫元素含量考察了磺化条件,并用熔融插层法制备了SPSBS/有机蒙脱土(OMMT)纳米复合材料,研究了复合材料的插层结构和拉伸性能。结果表明,在丙酮/环己烷为混合溶剂(丙酮体积分数为10%)、PSBS质量浓度为0.10～0.15 g/mL、硫酸/PSBS(质量比)为8.5/100、乙酸酐/硫酸(摩尔比)为1.69、反应温度为25℃、反应时间为15～40 min的条件下,PSBS可温和地进行磺化反应制得SPSBS,且反应过程中无凝胶产生;在SPSBS/OMMT纳米复合材料中,SPSBS插层进入OMMT片层间,且插层效果优于PSBS和苯乙烯-丁二烯-苯乙烯三嵌段共聚物(SBS);随着磺化度的增加,SPSBS的插层效果越好;SPSBS的拉伸性能优于PSBS和SBS,SPSBS/OMMT纳米复合材料的拉伸性能也优于PSBS/OMMT和SBS/OMMT纳米复合材料,且随着磺化度的增加,SPSBS/OMMT纳米复合材料的拉伸性能逐渐提高。     

丁二烯-苯乙烯共聚物改性沥青的研究进展

介绍了丁二烯-苯乙烯共聚物改性沥青的发展状况,分析了聚合物改性剂苯乙烯-丁二烯-苯乙烯嵌段共聚物(SBS)、丁苯橡胶(SBR)与基质沥青的分散性、溶胀性和相容性问题,着重论述了丁二烯-苯乙烯共聚物化学改性沥青的可能性。指出SBS、SBR与沥青适当相容并达到均匀分散,是充分发挥改性效果的前提;化学改性以及复合改性技术是提高沥青性能的重要手段。     

聚烯烃弹性体/苯乙烯-丁二烯-苯乙烯嵌段共聚物改性沥青混合料的抗老化性能

采用聚烯烃弹性体（POE）对苯乙烯-丁二烯-苯乙烯嵌段共聚物（SBS）改性沥青进行复配改性,制备了POE/SBS改性沥青混合料。考察了POE用量对SBS改性沥青抗老化性能的影响。结果表明,POE/SBS复配改性能提升沥青混合料的高温抗老化性能,且对低温性能有一定的改善效果。POE改善了SBS改性沥青混合料的抗车辙和抗老化性能,但会在一定程度上降低其低温韧性。当在沥青中加入质量分数分别为4%和3%的SBS和POE,POE/SBS改性沥青混合料的综合性能较佳。     

坡缕石对苯乙烯-丁二烯-苯乙烯嵌段共聚物改性沥青性能的影响

研究了坡缕石对苯乙烯-丁二烯-苯乙烯嵌段共聚物(SBS)改性沥青性能的影响.结果表明,坡缕石特殊的层链状结构和大的比表面积不仅改善了SBS改性沥青的低温性能和抗老化性能,同时形成的 .网状结构使SBS改性沥青稳定性增强.     

苯乙烯-丁二烯-苯乙烯嵌段共聚物改性沥青剪切发育过程的动态力学分析

用4种苯乙烯-丁二烯-苯乙烯嵌段共聚物（SBS）改性2种不同组分的基质沥青,通过温度扫描试验和常规实验,研究了改性沥青在不同剪切与发育时间的动态力学性能与物理性能,分析了在生产过程中影响SBS改性沥青质量的因素。结果表明,SBS改性沥青的损耗因子（tanδ）峰值在剪切发育过程中均减小;SBS改性含有适量沥青质和芳香分的沥青A经过发育后,其tanδ峰值降低,且在40—90℃出现平台值;SBS改性组分不平衡的沥青B的tanδ随温度上升而增加;SBS改性沥青A的储能模量（E’）与损耗模量（E”）在剪切初期有较大幅度增加,在发育过程中,其变化幅度很小,E’的增加幅度比∥大;SBS改性沥青B的E’与E”在发育过程中有较大幅度增加;适当的剪切发育时间使SBS改性沥青的延度增大,黏度增加;发育20h后,SBS改性沥青的延度明显下降,黏度增长幅度过大;相容性好的沥青需要适当的发育过程,以不超过4h为宜,相容性差的沥青不需要发育过程。     

溶胀接枝法制备具有微-纳米表面结构的苯乙烯-丁二烯-苯乙烯接枝共聚物(英文)

中对苯乙烯-丁二烯-苯乙烯嵌段共聚物(SBS)与马来酸酐进行了溶胀接枝反应,当接枝率控制在11.5%时可以获得微-纳米表面粗糙结构的接枝聚合物,水在SBS接枝共聚物的表面接触角明显减小。关键词:苯乙烯-丁二烯-苯乙烯嵌段共聚物;溶胀接枝法;微-纳米表面结构;表面接触角     

苯乙烯-丁二烯-苯乙烯嵌段共聚物极性化研究进展

综述了苯乙烯-丁二烯-苯乙烯嵌段共聚物极性化在大分子化学改性和负离子原位聚合改性这两种方法中的研究进展,详细阐述了两种方法的技术手段及优缺点,并对极性化后SBS的应用进行简单概述.     

用偶联法合成极性官能化苯乙烯-丁二烯-苯乙烯嵌段共聚物

以环己烷为溶剂、正丁基锂为引发剂、环氧氯丙烷为偶联剂合成了极性官能化苯乙烯-丁二烯-苯乙烯嵌段共聚物(SBS),研究了偶联剂用量、偶联反应的温度和时间及苯乙烯-丁二烯活性双嵌段聚合物(SB)的分子量对偶联反应的影响,以及偶联效率对极性官能化SBS力学性能的影响。结果表明,偶联效率随偶联剂用量增加和偶联温度升高而先升高后降低;随着SB数均分子量的增大,偶联效率逐渐降低。当偶联剂与正丁基锂的摩尔比为0. 6、偶联温度为80～90℃时偶联效率最大,可达80%以上,且偶联反应可在5 min内完成。极性官能化SBS的力学性能要优于市售线型SBS。     

用乙烯基吡啶改性苯乙烯-丁二烯-苯乙烯嵌段共聚物

通过采用1,1-二苯基乙烯作为降活剂降低苯乙烯-丁二烯-苯乙烯嵌段共聚物(SBS)活性大分子的活性,然后用2-乙烯基吡啶进行封端聚合,合成了苯乙烯-丁二烯-苯乙烯-2-乙烯基吡啶多嵌段共聚物,研究了降活剂和单体用量及反应条件对聚合的影响。结果表明,在降活剂用量控制为活性中心的1.0倍(摩尔比)、2-乙烯基吡啶质量分数控制为活性SBS的3%以下、反应温度在60～83℃及反应时间不少于35min时能够制得相对分子质量可控且分布较窄的嵌段共聚物。     

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。