PC/PBT合金材料的制备与改性

分别采用POE-g-GMA、PTW、MBS相容增韧剂,通过熔融共混挤出,对PC/PBT合金材料进行相容增韧改性,研究增韧剂的用量对PC/PBT合金材料力学性能的影响,并通过SEM电镜照片分析了共混物的断面形态。结果表明,随增韧剂用量的增加,材料拉伸强度降低。PTW、MBS对合金的增韧效果较好,尤其PTW用量为10wt%时,其缺口冲击可达到55k J/m2。     

ACR增韧PBT/PC合金的研究

研究了“核-壳”结构的ACR对PBT/PC(质量比80/20)合金的力学性能和耐热性的影响。结果表明:随着ACR用量增加,共混物的缺口冲击强度不断增大,而拉伸强度、弯曲强度、维卡耐热度降低。当ACR的加入量为5份时,缺口冲击强度提高1倍,当ACR的加入量为30份时,缺口冲击强度约为纯PBT/PC合金的5倍。从增韧效果来看,FM50略好于KM355。     

PC/PBT改性聚丙烯的研究

以聚碳酸酯(PC)和聚对苯二甲酸丁二醇酯(PBT)并用且以马来酸酐接枝聚丙烯(PP-g-MAH)作为相容剂来改性聚丙烯(PP),详细研究了PC/PBT改性PP的工艺条件以及不同结构对PP共混物性能的影响。结果表明,当PC与PBT的质量分数分别为5.0%和2.5%时,改性PP共混物的拉伸强度为24.0 MPa,缺口冲击强度达到28.9kJ/m~2,比未改性PP的冲击强度提高了7倍。同时研究了PP-g-MAH的用量对PP共混物性能影响,当PC与PBT的质量分数分别为10.0%和5.0%时,PP-g-MAH的质量分数为2.0%时,共混物的缺口冲击强度达到27.8kJ/m~2。PP-g-MAH可有效提高PC/PBT与PP之间的相容性。     

磷酸化合物对PBT/PC共混物性能的影响

将聚磷酸铵(APP)、焦磷酸钠(SPP)及磷酸三苯酯(TPP)作为酯交换反应抑制剂,分别与聚对苯二甲酸丁二醇酯(PBT)/聚碳酸酯(PC)进行熔融共混,并对不同共混体系的性能进行了研究。DSC用于研究抑制剂与PBT/PC共混体系共混物的结晶行为变化。结果表明,延长共混时间,酯交换反应程度提高,PBT结晶能力减弱,结晶温度降低,三种磷酸化合物对PBT/PC共混物的酯交换反应都能起到抑制作用;DMA用于研究了共混物的相容性,结果表明,抑制剂加入导致PBT与PC发生相分离;红外光谱用于研究共混物基团的特征吸收峰变化情况,结果证明,抑制剂不能完全阻止酯交换的发生;冲击试验机用来测试共混物的冲击强度的变化,结果发现,纯PBT/PC的冲击强度为24 J/m,含有抑制剂的共混物的冲击强度提高,加入TPP后的共混体系缺口冲击强度达到130 J/m左右。     

新型增韧剂增韧PC/PBT合金的研究

研究了3种增韧剂PTW、AX8900、FT862对PC/PBT合金力学性能和结晶性能的影响,并对PC/PBT合金的微观形态结构进行了分析.研究表明:增韧剂的加人,改善了两相间的相容性,提高了PC/PBT(30/70)合金的缺口冲击强度;当其质量分数达到15%时,合金材料发生脆韧转变,此时合金的缺口冲击强度为纯PC/PBT的10倍多;3种增韧剂中的甲基丙烯酸缩水甘油(GMA)含量越高,其增韧效果越好.     

POE熔融接枝GMA的制备及其与PBT共混增韧

在双螺杆挤出机上采用熔融接枝法制备了POE-g-GMA和POE-g-(GMA-co-St),考察了POE、POE-g-GMA和POE-g-(GMA-co-St)对聚对苯二甲酸丁二醇酯(PBT)的增韧作用.结果表明POE和单组分接枝的POE-g-GMA对PBT的缺口冲击韧性的改善作用都不大;而双组分接枝的POE-g-(GMA-co-St)对PBT具有显著的增韧作用.当弹性体POE-g-(GMA-co-St)用量为15%时,共混物的缺口冲击强度为45.84 kJ/m2,是缺口冲击强度为1.28 kJ/m2的纯PBT的35倍多.SEM显示,PBT/POE-g-(GMA-co-St)共混体系中分散相比PBT/POE-g-GMA共混体系的分散相具有更好的分散性.同时对比了几种外来增韧剂对PBT性能的影响.     

新型增容剂增容PC/PBT的研制及应用

研究了丙烯酸酯与羧基双官能化的乙烯类弹性体(RC)对聚碳酸酯(PC)/聚对苯二甲酸丁二酯(PBT)(质量比为80:20)共混体系相容性和力学性能的影响,比较了RC与其它增容剂的增容效果.结果表明,RC的加入改善了PC/PBT两相间的相容性;当RC的用量为5份时,PC/PBT的缺口冲击强度达到76.3 kJ/m2,为纯PC/PBT的8.3倍:用RC增容PC/PBT制备的汽车门把手质量良好,已得到客户认可,该材料还可用于其它要求冲击强度高和耐腐蚀的汽车内外饰件.     

乙烯-丙烯酸甲酯-甲基丙烯酸缩水甘油酯三元共聚物增韧PBT的研究

采用自制的不同接枝率的乙烯丙烯酸甲酯甲基丙烯酸缩水甘油酯三元共聚物(E MA GMA)增韧剂以及国外商业化增韧剂对聚对苯二甲酸丁二醇酯(PBT)进行增韧研究,将不同增韧剂与纯PBT树脂进行共混改性,研究了增韧改性PBT的缺口冲击强度、拉伸断裂伸长率和熔体流动速率等性能。结果表明,当自制增韧剂的接枝率为1.96 %,用量为15 %时增韧效果最好,材料的缺口冲击强度增加65 %,断裂伸长率增加30.6 %。     

TPU及TPU-g-MAH增韧废旧ABS的研究

研究了热塑性聚氨酯TPU及TPU-g-MAH对废旧ABS增韧效果的影响。结果表明:当TPU的用量为15份时,共混物缺口冲击强度为13.3 KJ/m2,比改性前提高了26.7%,当TPU-g-MAH的用量为20份,DCP用量为0.5份时,共混物缺口冲击强度为20.2 KJ/m2,比改性前提高了92.4%。     

相容剂对PBT／PC共混体系性能的改进

用DSC方法测试了PBT/PC（50/50,质量份）及经过相容剂（为PS接枝橡胶）处理的共混物,研究了相容剂用量对共混体系力学性能的影响。结果表明：相容剂的加入可使共混物中PBT的特点、熔融焓、结晶温度都分别比纯PBT有所降低,熔体流动速率和热变形温度有所下降。采用相容剂提高了PBT/PC共混体系两相间的相容性,改善了PBT的冲击性能,相容剂用量为15质量份时冲击强度达到最大值。     

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。