核—壳共聚物对光盘级聚碳酸酯的增韧研究

研究了甲基丙烯酸甲酯－丁二烯－苯乙烯共聚物（MBS）对光盘级聚碳酸酯的增韧作用，结果表明，MBS对PC增韧效果显著，且MBS分散性越好，达到晚一韧转变时所需的MBS含量越少，求得达到脆－韧转变时的临界粒间距为50nm，对共混物损伤机制的研究表明，MBS增韧PC共混物的增韧机理为MBS粒子的空洞化引发基体的剪切屈服。     

MBS对聚碳酸酯的增韧作用及其增韧机理的探讨

研究了甲基丙烯酸甲酯-丁二烯-苯乙烯共聚物（MBS）对光盘级聚碳酸酯的增韧作用。结果表明，MBS对PC增韧效果显著，且MBS分散性越好，根据逾渗理论，达到脆一韧转变时所需的MBS含量越少。求得达到脆-韧转变时的临界粒间距为50nm。对共混物损伤机制的研究表明，MBS增韧PC共混物的增韧机理为MBS粒子的空洞化引发基体的剪切屈服。     

ACR-g-VC冲击改性剂的性能与应用研究

对丙烯酸酯接枝氯乙烯共聚物（ACR-g-VC）增韧聚氯乙烯（PVC）体系的力学性能和加工性能进行了研究,通过与丙烯酸酯核－壳接枝共聚物（ACR）、氯化聚乙烯（CPE）增韧PVC体系的加工性能进行对比,发现其加工性能与ACR增韧PVC体系的加工性能接近。通过对PVC/ACR-g-VC与PVC／ACR的力学性能和形态结构的对比,分析了两种体系增韧效果差异的原因。实际应用研究表明,ACR-g-VC与CPE共同使用时有协同增韧作用。     

核壳型MBS增韧PC研究

利用双螺杆挤出机制备了核壳结构的甲基丙烯酸甲酯-丁二烯-苯乙烯塑料(MBS)与聚碳酸酯(PC)的熔融共混物。研究了MBS对PC/MBS合金常温力学性能和低温缺口冲击强度的影响;利用原子力显微镜观察了MBS在PC/MBS合金中的分布形态;扫描电子显微镜观察表明,MBS增韧PC的机理符合空穴理论。     

MBS树脂增韧PC的研究

利用双螺杆挤出机制备甲基丙烯酸甲酯-丁二烯-苯乙烯（MBS）树脂与聚碳酸酯（PC）熔融共混物。通过SEM观察得出：随着MBS用量的增加，改善了MBS与PC的相容性；力学性能结果表明：MBS的加入，提高了PC／MBS合金的缺口冲击强度，但合金的拉伸强度降低；PC／MBS合金的断裂表明：MBS增韧PC的机理是基体的剪切屈服和粒子的空洞化。     

透明聚氯乙烯改性剂MBS发展前景广阔

MBS是甲基丙烯酸甲酯－丁二烯－苯乙烯共聚物或丁苯胶乳接枝三元共聚物，形成核－壳型结构，内核是丁苯橡胶，外壳是聚甲基丙烯酸甲酯，核壳各保持自己的特有性质，又具有较好的热力学相容性，是透明聚氯乙烯制品良好改性剂，目前国内市场需求量约为25万吨／年，大部分依赖进口，供不应求，发展前景广阔。     

MBS粒子尺寸对PVC／MBS共混物性能及形变机理的影响

通过乳液聚合方法制备了两种不同粒径（分别为270nm和80nm）的甲基丙烯酸甲酯/丁二烯/苯乙烯（MBS）核壳改性剂，与聚氯乙烯（PVC）进行熔融共混，得到了PVC／MBS共混物。对PVC／MBS共混物力学、光学等方面的性能及其形变机理分别进行了考察。结果表明：PVC／MBS共混物的脆-韧转变温度（BDT）和拉伸性能均随着MBS粉料粒径的增加而增加；但是光学测试则表明MBS粒子对改善PVC基体的光学性能的效果却随MBS粉料粒径的增加而降低；透射电镜（TEM）的分析表明大粒径的MBS粉料能促使橡胶粒子产生空洞化，而由小粒径的MBS粉料制备的PVC／MBS共混物没有观察到橡胶粒子空洞化的产生。     

苯乙烯在MBS中的结合方式对PVC/MBS性能的影响

以乳液聚合法合成了化学组成恒定的具有核-壳结构的(甲基丙烯酸甲酯/丁二烯/苯乙烯)共聚物(MBS),通过改变原料及其配比,使苯乙烯(St)在MBS中以共聚或接枝方式结合,用动态力学热分析仪研究了MBS内耗与温度的关系。将MBS与聚氯乙烯(PVC)共混,研究了St结合方式对共混物冲击韧性及增韧机理的影响,结果表明,随着MBS核中St含量的增加,PVC/MBS共混物的脆-韧转变向高温移动;当St仅以接枝的方式结合时,橡胶粒子的空洞化及剪切屈服是主要的增韧机理,当St仅以共聚方式结合时,剪切屈服是主要的增韧机理。     

超韧阻燃PBT材料的制备与性能研究

以超韧阻燃聚对苯二甲酸丁二醇酯(PBT)为研究对象,探讨了弹性体乙烯-丙烯酸丁酯-甲基丙烯酸缩水甘油酯共聚物(PTW)增韧体系、聚烯烃接枝甲基丙烯酸缩水甘油酯(POE-g-GMA)增韧体系以及核壳聚合物甲基丙烯酸甲酯-丁二烯-苯乙烯共聚物(MBS)/聚碳酸酯(PC)复合增韧体系等对PBT材料力学性能与阻燃性能的影响,同时探讨了十溴二苯乙烷与溴化环氧两种阻燃剂对PBT材料阻燃性能、力学性能以及产品色相等方面的影响.结果表明,MBS/PC复合增韧体系增韧效果最好,材料拉伸强度与弯曲强度保持率最高,同时对材料的阻燃性能的影响也最小;溴化环氧阻燃体系材料弯曲强度更高,拉伸强度与缺口冲击强度保持率更好,同时产品色相白度更高,其阻燃效率相对略低.     

ACR核层中交联单体对PC/ACR共混物性能的影响

用丙烯酸丁酯、交联单体和甲基丙烯酸甲酯经乳液聚合和后处理制备了聚丙烯酸丁酯(PBA)/聚甲基丙烯酸甲酯(PMMA)核壳结构的丙烯酸酯树脂(ACR),然后将ACR与聚碳酸酯(PC)共混进行增韧改性。研究了ACR核层中交联单体对PC/ACR共混物力学性能的影响,并用SEM对共混物冲击断面形貌进行了研究。结果表明:随着ACR核层中交联单体含量的增加,PC/ACR共混物的缺口冲击强度呈现先增加后降低的趋势,拉伸强度和弯曲强度变化很小。当交联单体B含量为10%时,PC/ACR共混物的冲击强度达到最大为50.4 kJ/m2,约是纯PC冲击强度的5倍。     

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.