玻璃纤维增强PBT/PC共混体系的研究

用双螺杆挤出机制备了不同组成的玻璃纤维增强聚对苯二甲酸丁二酯(PBT)／聚碳酸酯(PC)共混体系,研究了抗冲改性剂及酯交换抑制剂对共混体系力学性能的影响,并用扫描电子显微镜观察了不同共混体系的形态结构。结果表明,抗冲改性剂使共混体系冲击强度提高的同时,降低了共混体系的拉伸强度、弯曲强度及弯曲弹性模量;酯交换抑制剂的加入,降低了共混体系的力学性能,适当的酯交换反应有利于共混体系力学性能的提高;在该体系中PBT与PC相容性较好。     

核壳结构改性剂对PBT／PC共混物冲击强度的影响

采用乳液聚合技术合成了以聚丁二烯（PB）为核、以聚甲基丙烯酸甲酯（PMMA）为壳的及壳上接枝甲基丙烯酸环氧丙酯（GMA）的两种核壳结构改性剂MB、MB—g—GMA，分别用于聚对苯二甲酸丁二醇酯（PBT）／聚碳酸酯（PC）共混物的增韧改性。力学性能结果表明，改性剂质量分数为20％，PBT／PC用量比为50／50时，共混物冲击性能最佳。固定PBT,／PC用量比为50／50，MB质量分数为10％时，共混体系实现了脆韧转变，缺口冲击强度可达到1016．9J／m，实现了超韧，而MB-g-GMA质量分数为15％时，共混体系才发生脆韧转变；动态力学分析仪分析结果显示，PC与改性剂壳层PMMA相容性好，GMA的加入提高了PBT与改性剂的相容性；扫描电镜分析表明，两种粒子都能均匀分散在基体中；基体的剪切屈服和橡胶粒子的空洞化是PBT／PC共混体系主要的形变机理。     

ABS/PCM-PET合金的性能研究

采用共混的方法制备了丙烯腈-丁二烯-苯乙烯(ABS)/回收聚对苯二甲酸乙二醇酯(PCM-PET)合金材料。分别研究了ABS树脂、共聚酯、扩链剂、增韧剂等对合金材料性能的影响。结果表明:用高冲击ABS替代中冲击ABS或加入共聚酯后合金的韧性提高明显;扩链剂可增加材料的强度,断裂伸长率的增加较明显,但材料的熔体质量流动速率明显降低;采用苯乙烯接枝改性剂(S-g-M),将其加入ABS/PCM-PET合金中可使韧性显著改善,材料的缺口冲击强度从14.8 kJ/m2提升至19.5 kJ/m2。     

聚烯烃弹性体增韧改性聚碳酸酯的研究

用四种聚烯烃弹性体对聚碳酸酯（PC）进行了增韧改性。探讨了不同种类和用量的增韧剂对聚合物共混物力学性能的影响。结果表明，EVA的加入使共混物韧性改善最明显，当其用量为15％时，材料的缺口冲击强度提高至38．7kJ／m^2，为纯PC的25倍，但材料的拉伸强度急剧下降。POE—g—MAH对PC的增韧效果仅次于EVA，但共混物的拉伸强度降低程度比EVA小，且共混物的断裂伸长率提高很多。其它两种共混体系PC／EAA、PC／LLDPE-g—MAH的性能介于EVA和POE—g—MAH之间。综合考虑材料的各种机械性能，添加20％的POE—g—MAH的PC共混物的性能较佳。     

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 %。     

PC/PET共混合金相容性的研究

采用差示扫描量热仪、扫描电镜等测试手段对聚碳酸酯/聚对苯二甲酸乙二醇酯（PC/PET）共混合金的相容性进行研究。结果表明,未添加相容剂时,随PET含量的增加,共混合金的两个玻璃化转变温度有相互靠近的趋势,说明此体系部分相容。PET的加入可明显改善共混合金的加工流动性。PET含量为65 %左右时改善效果最佳。相容剂的加入使共混合金的拉伸强度和弯曲强度略有下降,但缺口冲击强度得到较大提高,在PC/PET（30/70）中添加3份乙烯-丙烯酸丁酯-甲基丙烯酸缩水甘油酯（PTW）或7份乙烯-丙烯酸乙酯共聚物（EEA）即可使缺口冲击强度由5.5 kJ/m2提高到10 kJ/m2以上。含有甲基丙烯酸缩水甘油酯（GMA）基团的相容剂PTW对两相界面的改善效果最好。     

SEBS—g—MAH对PO／PBT共混物性能影响

利用双螺杆挤出机制备聚碳酸酯（Pc）／聚对苯二甲酸丁二醇酯（PBT）／-B来酸酐接枝氢化苯乙烯-丁二烯啕E乙烯共聚物（SEBS-g—MAH）的共混物。通过扫描电子显微镜（SEM）、平板流变仪研究了SEBS-g—MAH对PC／PBT共混物的机械性能、断面形态结构、动态力学行为的影响。结果表明：SEBS-g—MAH提高了PC／PBT共混物的相容性,随着SEBS-g—MAH用量的增加,共混物的缺口冲击强度和断裂伸长率上升,拉伸强度和弯曲强度下降。当SEBS—g-MAH质量分数为5％时共混物的综合性能最佳,同时,SEBS-g—MAH的加入,并未对PC／PBT共混物的成型加工性能产生不良影响。     

高阻燃PC/PET合金材料的制备与性能

使用双螺杆挤出机熔融共混制备了聚碳酸酯/聚对苯二甲酸乙二醇酯(PC/PET)合金。研究了阻燃剂的种类、相容剂种类以及PET树脂的黏度对材料的阻燃性能、力学性能和热性能。结果表明,添加16%苯氧基四溴双酚A碳酸酯齐聚物,试样阻燃等级可以达到UL94 V-0级别(0.8 mm),缺口冲击强度达到50.2 kJ/m²,球压痕直径小于2 mm。三氧化二锑的加入会降低材料的耐热性能以及灼热丝起燃温度,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)对PC/PET合金的相容作用最优,材料的冲击强度最高。丙烯酸酯-丁二烯-苯乙烯共聚物(MBS)和丙烯酸酯-有机硅共聚物对材料的增韧效果较弱,但是灼热丝起燃温度可以达到875℃。选择中等黏度PET树脂有利于提高材料的热变形温度,减小球压痕直径而高黏度PET树脂则有利于提高材料的缺口冲击强度。     

EPDM和PE协同增韧聚苯乙烯

研究了两种增韧剂（PE和EPDM）和PS／SBS（85／10）共混物的相形态和耐冲击性能。分别单独加入PE和EPDM时体系的最大缺口抗冲强度为7.5kJ/m^2和14.7kJ/m^2，当同时加入PE和EPDM时体系的最大缺口抗冲强度为21.5kJ/m^2。可见，PE和EPDM对聚苯乙烯有明显的协同增韧作用。     

r-PET/POE/EAA共混材料性能的研究

以回收聚对苯二甲酸乙二醇(酯r-PET)为基体材料,乙烯-辛烯共聚(物POE)为增韧材料,乙烯-丙烯酸共聚物(EAA)为相容剂,制备了r-PET/POE/EAA共混材料。用DSC、SEM分析了POE及EAA对r-PET结晶性能、断面结构的影响,并测试了共混材料的力学性能。结果表明:加入12%POE后,r-PET/POE共混材料的熔融温度降低了1.76℃,结晶度降低了16.49%,断裂伸长率及缺口冲击强度明显提高,弯曲强度和拉伸强度略有下降;在r-PET/POE共混材料中加入1.5%EAA后,POE球状粒子嵌入r-PET基体中,二者相容性提高,结晶速率加快;与纯r-PET相比,r-PET/POE/EAA共混材料的断裂伸长率和缺口冲击强度分别提高了698.01%和227.45%柔,韧性也大幅度提高。     

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。