橡胶含量对ABS树脂性能的影响

采用聚丁二烯接枝苯乙烯-丙烯腈共聚物(PB-g-SAN)与苯乙烯-丙烯腈共聚物(SAN)熔融共混,制备了一系列丙烯腈-丁二烯-苯乙烯共聚树脂(ABS),考察了橡胶含量对该ABS树脂物理力学性能的影响。结果表明:随着橡胶含量的增加,ABS树脂的拉伸强度、弯曲强度、弯曲模量、熔体流动速率、热变形温度、密度和硬度均有所降低,而缺口冲击强度和断裂伸长率提高。因此可通过调节橡胶含量来制备具有不同物理力学性能的ABS树脂,以满足不同的应用需要。     

丙烯腈含量对ABS树脂性能的影响

通过乳液接枝聚合法合成丙烯腈-丁二烯-苯乙烯共聚物(ABS)接枝粉料,与苯乙烯-丙烯腈共聚物(SAN)树脂熔融共混得到ABS树脂。探究丙烯腈含量对ABS树脂性能的影响。结果表明：随着丙烯腈含量增加,ABS树脂的拉伸强度、冲击强度、耗散因数、体积电阻率、维卡软化温度以及两相之间相容性上升,但熔体流动速率、表面电阻率、介电常数下降。     

我国苯乙烯的生产消费现状及发展前景

苯乙烯是一种重要的基本有机化工原料，主要用于生产聚苯乙烯树脂（PS）、丙烯腈-丁二烯-苯乙烯三元共聚物（ABS）、苯乙烯-丙烯腈共聚物（SAN）树脂、离子交换树脂、不饱和聚酯以及苯乙烯系热塑性弹性体SBS等。[第一段]     

ABS/SAN/中粘度PMMA三元共混物的性能研究

制备不同配比的丙烯腈－丁二烯－苯乙烯（ABS）／苯乙烯－丙烯腈（SAN）／中粘度聚甲基丙烯酸甲酯（PMMA）合金，分别测试其缺口冲击强度、拉伸强度、热变形温度、熔体流动指数等，结果表明：ABS／SAN可以引发中粘度PMMA产生大量的银纹，从而大幅度提高共混物的冲击强度；引入中粘度PMMA可以提高ABS／SAN的耐热性能；添加中粘度PMMA，合金的流动性能呈现下降的趋势。     

Lanxess苯乙烯系列树脂新产品

据“Plastics ＆ Rubber Weekly，2006-09-29”报道，德国Lanxess（朗盛）公司在PDM2006（2006年英国塑料设计和模具展览会）上推出苯乙烯系列树脂和共混物新产品Lustran Ultra和Triax，Lustran以前叫Styrine树脂。Lustran Ultra4105和4000G是高耐热ABS（丙烯腈／丁二烯／苯乙烯共聚物）新牌号。     

芳纶1414增强ABS复合材料的性能研究

用短切芳纶1414(PPTA)对丙烯腈-丁二烯-苯乙烯共聚物(ABS)树脂进行增强改性,利用扫描电镜、热失重分析和力学性能测试等方法分析了ABS/PPTA复合材料的断面形态结构、热性能和力学性能。结果表明:当PPTA用量为5份时,ABS/PPTA复合材料的拉伸强度和拉伸模量分别比纯ABS树脂提高了11%和29%,弯曲强度和弯曲模量分别增至78.8MPa和2.9GPa;PPTA可增强ABS树脂在高温时的热稳定性,降低最大失重速率并,提高残炭量。     

Dow 化学公司本体法工艺及部分ABS产品

综述了美国Dow化学公司本体法生产丙烯腈－丁二烯－苯乙烯三元共聚物（ABS）工艺的演进过程。介绍了该公司根据产品特点和国外市场情况制定的推销策略。通过了解Dow化学公司改善其产品多样性的途径，为我国本体法生产ABS产品及其后续产品的开发应用提供参考。     

PA6/ABS共混物性能研究

将聚酰胺6（PA6）与市售的丙烯腈-丁二烯-苯乙烯（ABS）树脂共混,制备PA6/ABS共混物。研究了ABS树脂的用量对PA6/ABS共混物力学性能的影响;采用苯乙烯及丙烯腈共聚物（SAN）和ABS粉料熔融共混制得不同胶含量的ABS/SAN共混物。研究了不同胶含量的ABS/SAN共混物对PA6/ABS共混物力学性能的影响。在PA6/ABS/SAN共混物中引入苯乙烯-丙烯腈-马来酸酐共聚（SAM）树脂取代部分SAN树脂,研究了SAM树脂的加入及引入顺序的不同对共混物性能的影响。结果表明, ABS树脂的用量在50%～60%左右时共混物性能最佳。随ABS/SAN共混物胶含量提高,共混物的拉伸强度、弹性模量、弯曲强度和弯曲模量逐渐降低。随SAM树脂替代SAN量增加,共混物的拉伸和弯曲性能先降低后增加。但共混物熔体流动速率降低明显,而SAM树脂的引入顺序对共混物的力学性能影响不大。     

PMMA及AS在ABS高胶粉增韧回收ABS改性中的应用研究

利用聚甲基丙烯酸甲酯(PMMA)及丙烯腈-苯乙烯共聚物(AS)对经丙烯腈-丁二烯-苯乙烯(ABS)高胶粉增韧的回收ABS进行改性.研究表明,PMMA及AS均可以提高共混物的拉伸强度、弯曲强度及硬度,而冲击强度呈下降趋势,但除冲击强度及熔体质量流动速率外,添加PMMA的共混体系的力学性能等方面的指标优于添加AS的体系.     

SBS增韧回收ABS改性研究

利用聚甲基丙烯酸甲酯(PMMA)及丙烯腈-苯乙烯共聚物(AS)对丁二烯-苯乙烯-丁二烯(SBS)增韧的回收丙烯腈-丁二烯-苯乙烯塑料(ABS)进行改性以提高其表面硬度.研究结果表明,PMMA及AS在提高共混物表面硬度的同时还可以提高其拉伸强度、弯曲强度及硬度,而冲击强度则呈下降趋势;此外,添加PMMA的共混体系的各项力...     

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。