接枝POE和EPDM增韧尼龙6的性能

采用双螺杆挤出共混法,研究了接枝POE(乙烯-辛烯共聚物)和EPDM增韧剂增韧尼龙6的配方和生产工艺,探讨了增韧剂对尼龙6性能的影响。结果表明:增韧尼龙6的冲击强度得到很大提高,且明显改善了吸水性。     

新型增韧剂在尼龙6上的应用

比较了增韧剂I-NY与橡胶类、聚烯烃类增韧剂对尼龙6性能的影响。结果表明，随着增韧剂I-NY用量的增加，尼龙6的缺口冲击强度显著提高，当其质量分数为15％时，缺口冲击强度为28kJ／m^2，是纯尼龙6的10倍；且在改善冲击强度的同时，材料的弯曲和拉伸强度下降较少，是一种比较理想的尼龙增韧剂。     

新型热塑性弹性体增韧尼龙6的研究

采用双螺杆共混挤出法,研究了新型热塑性弹性体(TPE)作为增韧剂对尼龙6的增韧作用,分析了相容剂、增韧剂型号、尼龙6粘度、增韧剂与相容剂的含量及其质量比等因素对共混物性能的影响。     

增韧尼龙612/尼龙6合金的性能

采用双螺杆挤出机对尼龙612 (PA612)及PA612/尼龙6 (PA6)合金进行增韧改性,研究了增韧剂类型、添加量对PA612以及PA6添加量对增韧PA612/PA6合金的力学性能、熔体流动速率和维卡软化点温度的影响。结果表明,三元乙丙橡胶接枝马来酸酐(EPDM-g-MAH)、聚烯烃弹性体接枝马来酸酐(POE-g-MAH)、聚乙烯接枝马来酸酐(PE-g-MAH)三种增韧剂对PA612起到了不同程度的增韧效果,其中EPDM-g-MAH效果最明显;当EPDM-gMAH的添加量由0份增至20份时,材料的断裂伸长率、简支梁缺口冲击强度逐步提高,而拉伸强度、弯曲强度、熔体流动速率、维卡软化点温度逐步降低,EPDM-g-MAH添加量变化对材料的简支梁缺口冲击强度影响最大,而对维卡软化点温度影响最小。添加15份EPDM-g-MAH增韧不同配比的PA612/PA6合金,当PA6的用量由0份增至85份时,增韧PA612/PA6合金的拉伸强度、弯曲强度、维卡软化点温度、吸水率逐步提高,而断裂伸长率、简支梁缺口冲击强度逐步降低,PA6添加量变化对材料的吸水率影响最大,而对材料的简支梁缺口冲击强度影响最小。     

聚烯烃接枝系列产品对尼龙6的增韧研究

主要考察聚烯烃接枝系列产品对尼龙6的增韧研究。以各种基础聚合物与顺丁烯二酸酐为主要原材料,经反应挤出制备系列增韧剂,考察了系列增韧剂用量对尼龙弯曲强度和缺口冲击强度的影响。结果表明,随增韧剂用量的增加,弯曲强度降低,缺口冲击强度增加;在10%~20%添加范围内,增韧剂b的效果最好。     

高流动性尼龙6的增强增韧改性研究

采用熔融共混方法,制备了高流动性尼龙6和尼龙6的增强增韧改性材料,考察了增韧剂添加量对改性材料的加工流变和力学性能的影响。结果表明,高流动性尼龙6的增强增韧改性材料的熔体流动性优于尼龙6的增强增韧改性材料,当增韧剂质量分数为10%~15%时,高流动性尼龙6的增强增韧改性材料力学强度和冲击韧性均优于尼龙6的增强增韧改性材料,实现了材料高刚度性能和高抗冲击性能的完美平衡。     

增韧剂在尼龙6中的应用研究进展

添加增韧剂是提高尼龙6韧性的主要手段,综述了近年来国内外五种增韧剂在尼龙6中的应用进展并对其增韧机理进行了阐述,展望了尼龙6增韧剂的发展方向。     

尼龙6/尼龙66合金的性能研究

研究了相容剂、增韧剂对改性尼龙6／尼龙66合金性能的影响。研究结果表明，以EVA／PE－g－MAH为相容剂、以PA6和PA66为基料、以EAA及PE为得合增韧剂改性的PA6／PA66合金，其吸水率有较大降低，且综合性能较好。     

新型尼龙增韧剂对尼龙6增韧的研究

采用新型双官能化增韧剂SWR-3C对尼龙(PA)6进行增韧研究。结果表明,随着SWR-3C用量的增加,PA6的冲击强度显著提高,当室温下SWR-3C的质量分数为20％时,PA6的冲击强度达94．5kJ／m^2,接近纯PA6的10倍,达到了超韧PA的性能指标,而且在改善其冲击强度的同时,材料的其它力学性能降低较小;并与国内外其它PA增韧剂进行了性能比较。     

玻璃纤维增强尼龙复合材料新型增韧剂研究

以马来酸酐接枝反式-1,4-聚异戊二烯(TPI-g-MAH),马来酸酐接枝乙烯–辛烯共聚物(POE-g-MAH)、马来酸酐接枝三元乙丙橡胶(EPDM-g-MAH)和马来酸酐接枝氢化苯乙烯–丁二烯–苯乙烯共聚物(SEBS-g-MAH)为增韧剂,以质量分数为15%的玻璃纤维(GF)为增强剂,通过双螺杆挤出机制备了一系列增韧型GF增强尼龙(PA)6复合材料,研究了增韧剂种类及含量对复合材料力学性能和熔体流动速率(MFR)的影响。结果表明,随着增韧剂含量的增加,复合材料的缺口冲击强度逐渐上升,拉伸强度、弯曲强度和MFR逐渐下降;其中,EPDM-g-MAH对复合材料的增韧效果最好,TPI-g-MAH和POE-g-MAH次之,SEBS-g-MAH的增韧效果最差;当增韧剂质量分数均为10%时,TPI-g-MAH增韧的复合材料的缺口冲击强度与EPDM-g-MAH增韧的已相差不大,且相对于其它增韧剂,TPI-g-MAH增韧的复合材料的拉伸强度、弯曲强度和MFR下降幅度最小。综合可知,TPI-g-MAH对GF增强PA6复合材料增韧效果明显且对其强度和MFR影响最小,是一种新型高效的增韧改性剂。     

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。