HIPS改性用低门尼F-250的开发

介绍了合成橡胶装置HIPS改性用低门尼F-250的生产技术及在HIPS中的应用情况,对低门尼F-250与正常门尼F-250以及国内外同类产品的性能进行了比较。实际应用表明:降低分子量和凝胶含量后,采用抗氧剂B,门尼粘度控制在40±10的低门尼F-250对HIPS改性具有优良的性能。但降低门尼粘度和分子量,偶合率不变,F-250拉伸强度降低,在轮胎中的应用性能有所影响。     

低顺式聚丁二烯橡胶质量改进的研究(Ⅱ)试生产及质量优化

经过工业试生产试验：选用防老剂A替代防老剂B、降低聚合反应温度、调整干燥系统操作参数并利用统计调优法对橡胶挥发分和凝胶含量进行优化控制，得出膨胀机的最佳操作温度；时试生产的低顺橡胶产品进行了HIPS改性应用试验。结果表明：产品质量满足用户要求，部分性能已达到或超过国外同类产品水平。     

高光泽高抗冲聚苯乙烯的结构与性能

利用激光粒径分析仪、动态力学分析仪和气相色谱-液相质谱联用仪等分析了高光泽高抗冲聚苯乙烯(HIPS)和普通HIPS的结构和性能。结果表明:两个高光泽HIPS(HIPS A和HIPS B)试样在力学性能上的表现各有侧重。高光泽HIPS的溶胀指数与普通HIPS(HIPS C)相近,为11.0左右,表明三个试样的交联程度相近。相对于高顺式聚丁二烯橡胶改性的HIPS,高光泽HIPS中苯乙烯与橡胶的接枝点数量多,光泽度提高了约三倍,橡胶相平均粒径为1.0μm左右且分布较窄,凝胶质量分数大于22.0%,低相对分子质量组分的质量分数为2.1%～2.9%,但硬脂酸锌添加量大。HIPS A,HIPS B,HIPS C中的增塑剂含量逐渐增加。     

复合橡胶改性聚苯乙烯的结构与性能

研究了复合橡胶对高抗冲聚苯乙烯(HIPS)结构与性能的影响,并用透射电子显微镜对HIPS进行了表征。结果表明:低顺聚丁二烯橡胶(简称低顺橡胶)能增加HIPS橡胶相体积分数,使橡胶粒子形态分布更均匀;高顺聚丁二烯橡胶(简称高顺橡胶)有利于提高产品的韧性;低顺橡胶对HIPS弯曲强度和拉伸强度的增加贡献更大;采用高顺橡胶与低顺橡胶复合,能够协调HIPS的韧性、弯曲强度和拉伸强度。     

低顺橡胶的工业生产与应用

介绍了茂名橡胶装置低顺式聚丁二烯橡胶(LCBR)的工业化生产及国内应用情况，并且与国外LCBR的质量及在HIPS改性性能上进行了对比分析。针对国产LCBR在生产和应用上存在的问题，分析了原因，对产品质量进行了改进，取得了较好效果。     

锂系低乙烯基聚丁二烯橡胶的开发与应用

本文主要介绍了国外锂系低乙烯基聚丁二烯橡胶的开发、生产状况及其特点,并介绍了低乙烯基聚丁二烯的应用,尤其用作聚苯乙烯改性胶,生产高抗冲聚苯乙烯(HIPS),与我国多套引进的 HIPS技术配套,急待在我国开发。     

高抗冲聚苯乙烯的研制 Ⅱ 预聚合反应过程及形态结构的研究

考察了各种条件下高抗冲聚苯乙烯(HIPS)的本体预聚合反应和相转变过程。并对采用不同基础胶制备的HIPS产品的形态结构进行了研究,发现低顺式聚丁二烯橡胶改性产品的形态结构在某些方面优于高顺胶体系。     

Nano-TiO2/HIPS母料流变性能的研究

采用Rosand Rheometer流变仪研究了nano-TiO2/HIPS母料及EVA蜡改性母料的流变性能。结果表明,nano-TiO2对母料的表观粘度影响较小。在nano-TiO2质量分数低于20％时，表观粘度仅略高于纯HIPS。在低剪切速率下。nano-TiO2可加速熔体偏离牛顿流体的速度。体系的粘弹性增强；而在较高剪切速率下则相反。EVA蜡可在较大范围内调整母料体系的流变性能。在低剪切速率下，EVA蜡质量分数超过5％就可明显改善体系的流动性，且体系流动行为接近牛顿流体，粘弹性很弱；在高剪切速率下，EVA蜡对体系的流动性影响不大，流变行为及牯弹行为与纯HIPS相当。原子力显微镜测试表明。采用EVA蜡改性的nano-TiO2/HIPS母料。可得到表观及分散性良好的制品。     

高抗冲聚苯乙烯的研制 Ⅲ.橡胶粒径分布及其对HIPS性能的影响

采用本体-悬浮法研究了高抗冲聚苯乙烯(HIPS)所用橡胶的结构及工艺条件对产品性能的影响。研究发现,随橡胶中乙烯结构含量的增加,HIPS橡胶接枝率增加;低顺胶HIPS橡胶相与PS相的相容性较差,高顺胶HIPS橡胶相与PS相的相容性好;从力学性能看,各种胶的HIPS拉伸性能相似,高顺胶的HIPS冲击性能最好,低顺线型胶次之,低顺星型胶较差。聚合过程中搅拌速度、橡胶用量及引发剂种类对HIPS的结构及性能也有一定影响。     

橡胶粒子对HIPS性能的影响

低顺式橡胶乙烯基含量高,合成的HIPS橡胶相体积分数较大,所含的胶粒较大,产品柔韧性、耐热性能较好;高顺式橡胶乙烯基含量较低,合成的HIPS橡胶相体积分数较小,所含的胶粒较小,产品抗冲击性能较好。使用适当比例掺合的增韧胶,可以获得综合性能良好的HIPS。相关的工艺条件对HIPS性能有一定影响。     

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。