核-壳结构共聚物增韧聚丙烯的研究

以聚丙烯（T36F）为基料,考察了核-壳结构共聚物（SEP）和三元乙丙橡胶（EPDM）对聚丙烯的增韧作用。结果表明：SEP作为聚丙烯（PP）的增韧添加剂比EPDM有更好的增韧效果。当SEP用量为10phr时,PP／SEP共混材料的缺口冲击强度是纯PP的7．7倍,超过了20份EPDM增韧PP的效果,是优良的PP抗冲增韧改性剂。     

苯乙烯-二元乙丙橡胶嵌段共聚物增韧聚丙烯

考察了苯乙烯-二元乙丙橡胶嵌段共聚物（SEP）和三元乙丙橡胶（EPDM）对聚丙烯（PP）的增韧作用。结果表明，SEP比EPDM具有更好的增韧效果。SEP以核-壳形态分布于PP基质中，有效地诱导PP基质产生银纹和剪切屈服，消耗大量的冲击能，SEP用量为10份时，PP/SEP共混材料的缺口冲击强度较纯PP的提高7-8倍，超过了20份EPDM增韧PP的效果，是一种新型的PP抗冲增韧改性剂。     

三元乙丙橡胶共混改性聚丙烯

分别用茂金属催化聚合所得的三元乙丙橡胶(mEPDM)和传统Ziegler-Natta催化剂聚合所得的三元乙丙橡胶(EPDM)对PP进行共混改性。考察了增韧剂质量分数对共混物冲击强度、拉伸强度和热变形温度等力学性能的影响,以及共混物结构形态和结晶行为。结果表明,与PP／EPDM共混物相比,PP／mEPDM共混物的脆韧转变增韧剂临界质量分数小,扯断伸长率高。PP／mEPDM共混物的脆韧转变区间远小于PP／EPDM共混物。随增韧剂质量分数的增加,PP／mEPDM和PP／EPDM共混物的拉伸强度、弹性模量和维卡软化点均单调下降,但后者的下降幅度更大。电镜分析和结晶行为研究表明,PP与mEPDM的相容性优于PP与EPDM的。     

PPO／PA6／EPDM／滑石粉共混体系的加工－性能－形态之间关系研究

采用熔融共混法制备了聚苯醚(PPO)/聚酰胺6(PA6)/三元乙丙橡胶(EPDM)三元和PPO/PA6/EPDM/滑石粉四元体系的共混合金,而且在制备四元共混合金时采取先用马来酸酐接枝的三元乙丙橡胶(EPDM-g-MAH)与滑石粉制成母粒,然后再将母粒与PPO、PA6共混的方法,研究了三元和四元共混体系的力学性能、流变性能和相态结构。结果表明:将制备的母粒与PPO和PA6进行共混,当母粒含量在一定范围内时可以实现弹性体和无机刚性粒子对体系的协同增韧作用,且母粒含量在15％时达到最佳,其增韧效果优于相同用量的纯EPDM-g-MAH弹性体增韧体系,同时母粒的加入可以改善共混体系的流动性,对拉伸强度的影响也比较小。     

SIS/SBS/PP共混改性的研究

研究了新型聚丙烯(PP)合金材料的配方、制备、工艺及性能。分别讨论了不同用量的三元乙丙橡胶 (EPDM)、苯乙烯与异戊二烯嵌段共聚物(SIS)及苯乙烯与丁二烯嵌段共聚物(SBS)与PP组成的二元和三元共混体系对材料力学性能的影响。结果表明:SIS为PP较好的增韧剂,PP／SIS/SBS三元共混体系具有较好的协同效应,在某种程度上可以代替EPDM改性PP,共混改性后拉伸强度、扯断伸长率等性能优良。     

PP/POE及PP/EPDM共混改性研究

以茂金属聚烯烃弹性体(POE,乙烯-辛烯共聚物)和三元乙丙橡胶(EPDM)作为聚丙烯(PP)的增韧剂,研究了PP/POE及PP/EPDM共混物的加工性能及力学性能。研究结果表明,POE在加工性、增韧改性等方面比EPDM更具有优势。借助扫描电子显微镜(SEM)进一步探讨了共混物的形态结构与性能的关系。     

高流动性PP增韧体系流变性能的研究

利用毛细管流变仪和转矩流变仪对高流动性聚丙烯（PP）增韧体系的流变性能进行分析,讨论了聚烯烃弹性体（POE）、三元乙丙橡胶（EPDM）=增韧母料和降温母料等助剂对高流动性PP共混体系流变性能的影响,并对PP/POE共混体系和PP/EPDM共混体系的转矩流变曲线进行了对比,考察了不同共混体系的微观结构、力学性能和加工性能。     

高抗冲高刚性EPDM改性聚丙烯的研究

加入超细改性无机刚性粒子提高三元乙丙橡胶(EPDM)的硬度，再与聚丙烯(PP)进行共混。研究了超细改性无机刚性粒子用量对EPDM硬度及流动性的影响，比较了PP与不同硬度EPDM的共混物在力学性能上的差异。结果表明：随着EPDM硬度的增加，共混物不仅韧性提高，弯曲模量也大幅度上升。选择合适的硬度，可制得高抗冲高刚性的EPDM改性PP共混材料。     

TBC对EPDM/PP阻燃化的影响

用氧指数(LOI)测定、力学性能测定、热失重分析(TGA)方法研究了TBC对三元乙丙橡胶(EPDM)／聚丙烯(PP)阻燃耐热性和力学性能的影响。结果表明，使用TBC，EPDM／PP的阻燃效果较好，TBC主要发挥气相阻燃作用。5％TBC的加入增加了共混体系的拉仲强度和断裂伸长率；但随着TBC用量的继续增加，拉伸强度和断裂伸长率都有所降低。加入TBC后，共混物的起始失重温度明显降低，但对EPDM／PP的热稳定性没有多大的影响，不影响EPDM／PP的正常使用。     

降解PP/EPDM共混物的力学性能

用过氧化二异丙苯(DCP)将聚丙烯(PP)降解,制备降解PP与三元乙丙橡胶(EPDM)共混物,测试降解PP/EPDM共混物的冲击和拉伸性能,研究共混物的脆—韧转变,结果发现温度和EPDM含量对PP/EPDM共混物的韧性影响规律是相同的,增加温度和增加EPDM含量都能使PP/EPDM共混物的韧性增加。     

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.     

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。     

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.