PVC/HIPS/增容剂共混改性研究

研究了原料配比、增容剂品种及用量、混炼方式等对PVC／HIPS／增容剂三元共混体系力学性能的影响;并对合金的流变性能及阻燃性进行了考察。结果表明：接枝共聚物HIPS-g—PMMA对PVC／HIPS合金具有增容作用,且增容效果随支链PMMA摩尔质量的增加而增加;PVC／HIPS／HIPS-g-PMMA合金仍为假塑性流体,表观黏度比纯PVC低,加工性能显著改善;PVC／HIPS／HIPS-g—PMMA合金具有较好的阻燃性。     

相容剂LLDPE-g-MAH的制备及其对LLDPE／PA6共混性能的影响

研究了以过氧化二苯甲酰为引发剂,线型低密度聚乙烯接枝马来酸酐的反应.采用正交实验方法考察了引发剂用量、单体浓度、反应时间及反应温度等对接枝反应的影响,优选出了接枝条件.将LIDPE-g-MAH作为一种增容剂加入到LLDPE/PA6共混体系中,考察了ILDPE/PA6共混体系中各相的相容性及共混物的力学性能.结果表明:LLDPE-g-MAH能有效地增强LLDPE/PA6共混体系两相界面的相互作用,改善ILDPE和PA6的相容性,为效果较好的增容剂.     

PPO/PA66合金接枝增容剂的制备及性能研究

为使聚苯醚（PPO）与尼龙（PA）更好地合金化，得到具有良好性能的共混合金，利用熔融挤出技术使高抗冲聚苯乙烯（HIPS）与马来酸酐（MAH）形成接枝物HIPS－g-MAH，对其增容。本文介绍了此接枝增容剂的制备方法，并对熔融挤出接枝工艺及影响因素进行了研究。结果表明：HIPS与MAH能形成接枝共聚物；引发剂（DCP）用量、接枝单体用量、反应时间、挤出机螺杆转速都对接枝效果有影响，其中引发剂（DCP）用量的影响最为明显。     

不饱和单体溶液接枝LLDPE及其应用

以二甲苯为溶剂。过氧化二异丙苯（ＤＣＰ）为引发剂，采用正交法对不饱和单体溶液接枝线性低密度聚乙烯（ＬＬＤＰＥ）进行了初步研究。了单体用量，ＤＣＰ 。反应温度和反应时间以接枝率和交联度的影响。确定影响反应的主要因素。并对接枝物对ＬＬＤＰＥ／淀粉降解体系的增容效果进行 探索。结果表明，接枝物是有效的ＬＬＤＰＥ／淀偻共混增容剂。     

氯化聚丙烯接枝马来酸酐的合成研究

考察了马来酸酐（MAH）用量、引发剂（BPO）用量、反应温度和反应时间对氯化聚丙烯接枝马来酸酐（CPPgMAH）中接枝率和接枝效率的影响。结果表明m（MAH）：m（CPP）=0．28时，接枝率和接枝效率较高；随着引发剂过氧化苯甲酰（BPO）用量的增大，接枝率和接枝效率也随之增大；提高反应温度，可以提高接枝效果，适宜的反应温度和反应时间分别为100℃、1．5h。     

聚丙烯接枝衣康酸增容PA6／PP共混物性能及形态研究

采用反应型双螺杆挤出机和熔融接枝技术制备了一系列聚丙烯（PP）接枝物，包括单一单体接枝物PP接枝衣康酸（PP-g-ITA）和双单体接枝物PP接枝ITA和苯乙烯[PP-g-（ITA-co-St）]，通过红外光谱和热分析研究了PP接枝物的结构，并研究了PP接枝物的接枝率和熔体流动速率与单体和引发剂用量的关系。通过反应挤出制备了PP接枝物增容PA6／PP共混物，研究了增容共混物的力学性能和形态结构。结果显示：加入接枝物后，共混体系的冲击强度明显提高；SEM观察表明，接枝物的加入能明显改善增容共混物的两相界面结合状况，降低共混物的分散相尺寸，改善体系的分散状况，共混物的两相界面变得模糊，相容性得到明显提高；DSC测试表明，加入接枝物后，共混物中PA6组分的结晶度下降，PP组合的结晶度上升。表明PP-g-ITA是PA6／PP共混体系有效的增容剂兼增韧剂。     

LDPE/PS就地相容化研究

在熔融状态下，利用Friedel-crafts烷基化反应就地增容低密度聚乙烯（LDPE）／聚苯乙烯（PS）合金，考察了催化剂品种及其用量、温度、时间等对接枝反应及合金性能的影响。结果显示，无水三氯化铝为一有效催化剂，能实现大分子间的接枝反应，形成LDPE-g-PS，其用量增大时可使体系产生凝胶；升高温度、延长反应时间都不利于接枝百分比的提高；增容后的LDPE／PS合金，其性能得到显著改善。     

相容剂对HDPE/PC共混合金性能的影响

采用熔融接枝方法制备马来酸酐接枝高密度聚乙烯(HDPE-g-MAH)和丙烯酸接枝高密度聚乙烯(HDPE-g-AA)，比较了这2种相容剂对HDPE／聚碳酸酯(Pc)共混合金体系的增容效果，着重研究了接枝单体、引发剂对HDPE接枝物的接枝率和熔体流动速率的影响及HDPE接枝物用量对HDPE／PC合金力学性能的影响。结果表明：HDPE-g-MAH相容剂的增容效果较好。用量为15份时使HDPE／PC合金缺口冲击强度提高了30％。     

PP-g-MMA制备及其在PVC/PP共混体系中的应用

用PP-g-MMA作为增容剂对PVC/PP共混体系进行改性。用紫外光辐照接枝的方法在聚丙烯(PP)上接枝极性单体甲基丙烯酸甲酯(MMA);讨论了光照时间、单体用量和光敏剂用量对接枝率的影响,用IR对接枝产物进行了表征。结果表明,加入增容剂显著改善了PVC/PP共混体系的力学性能,并且改善了PVC的加工性。扫描电镜(SEM)分析也表明增容剂对共混体系有很好的增容作用。     

PMMA-g-PS对CPE/PS共混体系性能的影响

采用大单体技术合成聚苯乙烯和甲基丙烯酸甲酯的规整接枝共聚物PMMA-g-PS。研究了共聚合反应条件聚苯乙烯大单体的投料质量分数、引发剂用量、反应温度对接枝效率的影响;研究PMMA-g-PS作为CPE/PS体系的共混增容剂时,共混物的组成、接枝物的用量、接枝物的组成对共混物物理机械性能的影响。用SEM,DSC表征共混物的变化,结果表明,接枝共聚物能促进两组分相容,起到增容剂的作用。     

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。