累托石／尼龙6复合材料结构与性能的研究

通过己内酰胺及累托石在甲醇钠作催化剂和甲苯二异氰酸酯助催化剂的存在下,原位聚合改性制备尼龙6复合材料,研究了累托石的加入对尼龙6的力学性能、热性能的影响。结果表明,改性后的尼龙6复合材料的弯曲强度、冲击强度等力学性能得以提高,通过改性还使制品的热稳定性和尺寸稳定性明显提高而吸水率大幅度降低。     

磨碎玻璃纤维在MC尼龙中的应用研究

考察磨碎玻璃纤维对铸型(MC)尼龙复合材料填料分布、物理力学性能的影响,以及增韧剂对MC尼龙复合材料韧性的影响。结果表明,磨碎玻璃纤维改性MC尼龙的物理力学性能优良,当加入10％的磨碎玻璃纤维时,制品收缩率降低,热变形温度提高20℃,制品具有填料分布均匀、外观光泽优良等优点;制品的拉伸强度比纯MC尼龙提高26％,弯曲强度提高13％,压缩强度提高36％。加入增韧剂六甲基磷酰三胺后,复合材料的韧性大幅度提高,添加量为5％-10％时,复合材料的综合力学性能最佳。     

玻璃纤维增强MC尼龙力学性能的研究

用玻璃纤维对MC尼龙复合材料进行改性,研究了玻璃纤维含量及长度对MC尼龙复合材料力学性能的影响。结果表明:玻纤含量50%的MC尼龙同玻纤含量40%的MC尼龙相比,冲击强度、拉伸强度、弯曲强度分别提高29.63%、5.43%,6.47%;MC尼龙复合材料的拉伸强度、弯曲强度及冲击强度随玻璃纤维长度的增长而增加,玻纤的长度越长,MC尼龙复合料力学性能提升效果越好;MC尼龙复合材料弯曲强度与玻纤重均长度为正相关关系,随着玻纤重均长度增大而增大。     

异辛酸稀土改性MC尼龙的研究

研究了己内酰胺在甲醇钠催化剂和甲苯二异氰酸酯助催化剂的存在下,采用异辛酸稀土改性的由阴离子开环原位聚合法制备MC尼龙复合材料的工艺,介绍了异辛酸稀土改性剂的制备方法,研究了异辛酸稀土改性MC尼龙的力学性能和热性能。结果表明,异辛酸稀土的加入可使MC尼龙的弯曲强度、冲击强度等力学性能得以提高;通过改性还能使制品的热稳定性、耐磨性和尺寸稳定性明显提高而吸水率大幅度降低。     

陶瓷微珠改性MC尼龙的研究

考察了陶瓷微珠对MC尼龙的物理、力学性能的影响。结果表明,陶瓷微珠改性MC尼龙的物理、力学性能优良。当陶瓷微珠的质量分数为10%时,制品的收缩率下降,热变形温度提高25℃以上,制品具有填料分布均匀、外观光泽性好等优点;弯曲强度、弯曲弹性模量、冲击强度都有所提高,其中弯曲强度提高15%以上,冲击强度也提高7%以上。综合考虑,质量分数10%的DT型陶瓷微珠改性MC尼龙的力学性能比较理想。     

空心玻璃微珠填充MC尼龙复合材料的研究

对空心玻璃微珠填充铸型(MC)尼龙进行了系列研究,考察了空心玻璃微珠含量、粒径及表面处理对MC尼龙性能的影响。结果表明,空心玻璃微珠改性MC尼龙复合材料的物理性能和力学性能优良,当加入10％表面处理的空心玻璃微珠时,制品的收缩率下降,热变形温度提高20℃以上,制品具有填料分布均匀、外观光泽优良等优点。与未处理的空心玻璃微珠相比,填充经表面处理空心玻璃微珠的复合材料拉伸强度、弯曲强度、断裂伸长率分别提高了15．7％、12．2％和246％。空心玻璃微珠的粒径愈小,复合材料的力学性能愈好。一定用量的玻璃微珠填充MC尼龙不仅可以使材料保持较好的力学性能和耐热性能,而且能够降低MC尼龙复合材料的成本。     

EVA/有机改性累托石复合泡沫材料的制备与性能研究

采用十二烷基三甲基溴化铵（DTAB）对累托石（REC）进行有机处理制备出有机改性累托石（OREC）,通过熔融插层法制备出了乙烯-醋酸乙烯共聚物/有机改性累托石（EVA/OREC）复合泡沫材料。利用傅里叶红外光谱仪（FTIR）、X射线衍射仪（XRD）、扫描电子显微镜（SEM）、万能试验机等对复合材料的形貌和力学性能进行了表征,研究了累托石的层间距、含量对复合泡沫材料力学性能的影响。结果表明,经有机改性后累托石层间距增加了10.9 %;复合材料的拉伸强度、断裂伸长率、撕裂强度也随之明显升高;且当OREC质量组分为10份时材料的各项力学性能达到最佳。     

环氧树脂/有机累托石纳米复合材料的研究

用十二烷基二甲基苄基氯化铵对累托石进行有机化处理，采用不同量的有机累托石与环氧树脂进行原位插层聚合，制得环氧树脂／有机累托石纳米复合材料，采用红外光谱分析、X射线衍射分析、扫描电镜分析、差示扫描量热分析和力学性能测试研究了有机累托石在环氧树脂中的分散性、纳米复合材料的力学性能和热性能。结果表明，有机累托石含量为3份时纳米复合材料的综合性能最佳，冲击强度和弯曲强度分别提高40％和33％；热变形温度和玻璃化转变温度分别提高30℃和11．5℃；而其热稳定性与纳米累托石粒子的分布和界面作用有关。     

超细滑石粉改性MC尼龙的研究

考察了超细滑石粉对MC尼龙复合材料物理力学性能的影响。结果表明,滑石粉与MC尼龙复合,显著地改善了制品的收缩率、吸水率,热变形温度提高24℃。制品具有填料分布均匀、外观光泽优良等优点。同时,加入滑石粉还可以降低MC尼龙制品的成本。硅烷偶联剂可以增加滑石粉与MC尼龙基体的相容性,使复合材料的冲击强度较MC尼龙提高11％。     

改性剂对氧化石墨烯/铸型尼龙复合材料力学性能的影响

采用改进的Humeers法制备氧化石墨烯(GO),然后使用环氧丙基三甲基氯化铵(GTMAC)、十六烷基三甲基溴化铵(CTAB)、马来酸酐接枝高密度聚乙烯(HDPE-g-MAH)和马来酸酐接枝超高分子量聚乙烯(UHMWPE-g-MAH)四种不同柔性链的改性剂分别改性GO。并经傅里叶红外光谱(FTIR)、X射线衍射(XRD)及扫描电子显微镜(SEM)等对改性GO及铸型(MC)尼龙复合材料进行测试和表征,结果表明:CTAB改性GO层间距最大,在尼龙基体中分散最好。力学强度测试结果表明:改性GO的分散性对复合材料的性能影响较大,使用CTAB改性GO制得的MC尼龙复合材料性能最佳,当GO-g-CTAB加入量为己内酰胺用量的0.05%时,与未改性GO/MC尼龙复合材料相比,其弯曲强度提高了9.3%,冲击强度提高了60%,拉伸强度和压缩强度也分别提高了2.0%和15.8%。改性剂链的柔性对铸型尼龙综合力学性能也有重要的影响,HDPE和UHMWPE改性GO的添加显著提高了复合材料的冲击性能,但材料的拉伸强度略有下降。     

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。