~1H-NMR法测定苯乙烯-乙烯-丁二烯-苯乙烯嵌段共聚物的加氢度和微观结构

采用核磁共振氢谱(1H-NMR)法测定苯乙烯-乙烯-丁二烯-苯乙烯嵌段共聚物(SEBS)的加氢度和微观结构。结果表明,采用镍系催化剂对苯乙烯-丁二烯-苯乙烯嵌段共聚物(SBS)进行加氢反应制备SEBS时,在苯乙烯链段未参与加氢反应的前提下,通过对SBS和SEBS的谱峰进行归属,建立了用1H-NMR测定SEBS总加氢度的方法,且无需已知苯乙烯的摩尔分数,适用范围较宽;用该法还可直接得到SEBS中各微观结构含量和丁二烯1,2-结构和1,4-结构的加氢度。     

苯乙烯-异戊二烯-苯乙烯三嵌段共聚物的环氧化

以甲酸和过氧化氢反应生成的过氧甲酸为氧化剂、聚乙二醇(PEG-400)为相转移催化剂,对苯乙烯-异戊二烯-苯乙烯三嵌段共聚物(SIS)进行了环氧化,考察了SIS的环氧化反应影响因素,并探讨了环氧化反应机理。结果表明,在C=C/甲酸/过氧化氢(摩尔比)为1/2/6、反应时间为2 h、反应温度为50℃、SIS质量分数为20%时,SIS的环氧化效果最好,环氧度可达到39. 2%;加入相转移催化剂PEG-400可以大幅度提高环氧度,当PEG-400/SIS(质量比)为1. 0时,环氧度可达到59. 5%; SIS的环氧化反应主要发生在聚异戊二烯链节中1,4-结构的双键上,且反应活性由强到弱依次为顺式-1,4-结构、反式-1,4-结构、3,4-结构。     

SDS型热熔压敏胶动态黏弹性及微相分离结构的研究

针对SDS(苯乙烯-二烯烃-苯乙烯嵌段共聚物)型HMPSA(热熔压敏胶)的相分离结构,采用DMA(动态力学分析)法及TEM(透射电镜)对SIS/SBS(苯乙烯-异戊二烯-苯乙烯嵌段共聚物/苯乙烯-丁二烯-苯乙烯嵌段共聚物)、SIS/SBS/增黏树脂和SIS/SBS/增塑剂共混物体系的流变行为进行了对比分析,并根据聚合物动态力学参数与微相分离结构的关联性,阐明了SDS型HMPSA的黏弹性机制。研究结果表明:SIS/SBS共混物存在三相分离结构,并具有较高的储能模量;增黏树脂、增塑剂通过选择性相容改变了原有热塑性弹性体的流变行为和相分离结构,前者为两相畴结构且产生了初粘力,后者仍保持三相畴结构且具有良好的柔韧性。     

SIBR微观结构的红外光谱定量分析

采用聚苯乙烯、聚丁二烯和聚异戊二烯标准样品复配,建立了利用红外光谱工作曲线来测定苯乙烯-异戊二烯-丁二烯橡胶(SIBR)中苯乙烯、丁二烯反式-1,4结构、丁二烯顺式-1,4结构、丁二烯-1,2结构、异戊二烯-1,2结构、异戊二烯3,4-结构和异戊二烯-1,4结构等7种微观结构的定量分析方法,解决了使用红外光谱联立解方程组法来测定SIBR多种微观结构含量的困难。该方法方便、准确、可靠,也适用于嵌段共聚物SIBS的微观结构测定。     

低挥发高接枝率马来酸酐接枝聚丙烯的制备及其在增强聚丙烯材料中的应用

利用含有双键结构的苯乙烯弹性体苯乙烯-丁二烯-苯乙烯嵌段共聚物(SBS)和苯乙烯-异戊二烯-苯乙烯嵌段共聚物(SIS),通过双螺杆挤出机进行反应性熔融挤出制备马来酸酐接枝聚丙烯(PP-g-MAH)。利用傅里叶变换红外光谱仪(FTIR)、熔体质量流动速率仪、水分测定仪和酸碱滴定法测定了PP-g-MAH的物质结构、熔体质量流动速率、挥发分含量和接枝率,通过双螺杆挤出制备了玻璃纤维(GF)/聚丙烯(PP)(30/70)复合材料,对复合材料的力学性能和微观形貌进行了研究。结果表明,添加SBS或SIS有利于PP-g-MAH熔体质量流动速率的提高、挥发分含量的降低和接枝率的提高;GF增强PP材料中GF与PP的相容性变好,其力学性能也有较大幅度的增加。     

聚苯乙烯为规整侧链的支化SIS的设计及合成

以苯乙烯和对乙烯基苄氯(VBC)为原料,采用负离子聚合法合成含苯乙烯基末端的聚苯乙烯大分子单体,并以正丁基锂(BuLi)为引发剂,四氢呋喃(THF)为调节剂,环己烷为溶剂进行异戊二烯与大分子单体的负离子共聚合,用一锅法制备出侧链规整的支化结构苯乙烯-异戊二烯-苯乙烯(SIS)嵌段聚合物。通过核磁共振和凝胶渗透色谱等对聚苯乙烯大分子单体和支化SIS结构进行了表征,利用旋转流变仪对支化SIS进行了流变性能表征。结果表明,利用上述聚合方法成功合成了相对分子质量3000～5000的聚苯乙烯大分子单体;使用聚苯乙烯大分子单体制备出相对分子质量为10万～14万,分子量分布为1.1～1.2的支化结构SIS,并且其流体黏度明显低于相同相对分子质量及结合苯乙烯线型结构的SIS。     

用相转移催化剂聚乙二醇环氧化苯乙烯-异戊二烯-苯乙烯三嵌段共聚物（英文）

利用甲酸和过氧化氢反应原位生成的过氧甲酸为氧化剂,以具有两亲性的聚乙二醇(PEG-400)为相转移催化剂,在甲苯溶剂中对苯乙烯-异戊二烯-苯乙烯三嵌段共聚物进行环氧化。结果表明,当PEG-400质量分数为1%时,产物环氧度由39.1%提高到59.5%,且环氧化反应主要发生在聚异戊二烯链段的1,4-结构双键上,1,4-结构的摩尔分数由50.70%下降到33.55%,特征峰位置没有明显变化。     

液体抗氧剂优配B7081L在钕系顺丁橡胶中的应用

利用活性阴离子聚合的方法设计并合成了一系列可控窄相对分子质量分布的硅氢功能化苯乙烯-异戊二烯-苯乙烯嵌段共聚物（SIS）线形前驱体,苯乙烯嵌段物质的量分数可达0.91以上,通过偶联剂将线形前躯体偶联成臂数可控（有效控制为8臂左右）的硅氢功能化SIS星形弹性体。本研究拓展并延伸了SIS星形弹性体的功能,为合成各种功能化SIS星形弹性体提供了新思路和新方法。     

苯乙烯-异戊二烯-苯乙烯产业的国内外市场分析与展望

苯乙烯-异戊二烯-苯乙烯（SIS）热塑性嵌段共聚物是热塑性弹性体SBS（苯乙烯-丁二烯-苯乙烯热塑性嵌段共聚物,俗称第三代橡胶＂＂）的姊妹产品,同为SBC（苯乙烯系热塑性弹性体）的重要品种。苯乙烯-异戊二烯-苯乙烯是美国菲利浦斯石油公司和壳牌化学公司分别于上世纪60年代同步开发并实现工业化生产的新一代热塑性弹性体。     

由裂解C_5与苯乙烯合成SIS嵌段共聚物的研究 Ⅱ.聚合工艺研究与结构性能表征

介绍了以精制 C5为原料 (即低纯度异戊二烯 ,其中异戊二烯含量为 45～ 5 5 % ,异戊二烯以外的组分用作聚合溶剂 )与苯乙烯进行嵌段共聚合制备 SIS的新工艺。所得 SIS的微观结构、力学性能及在粘合剂方面的应用情况与国外相应的由高纯度异戊二烯合成的 SIS基本一致。     

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。