带烯键含芴聚芳醚酮增韧改性双马来酰亚胺树脂

采用无溶剂自相溶工艺,将侧链带有烯键的含芴聚芳醚酮(RPFEK)溶解于二烯丙基双酚A（DABPA）,低温下加入4,4′-二氨基二苯甲烷双马来酰亚胺(BMDM)进行熔融共聚,再用高温固化的方式制备了带烯键含芴聚芳醚酮增韧的改性双马来酰亚胺（BMDM/DABPA）复合材料。结果表明,这种复合材料是一种互穿交联网络结构,RPFEK的引入不但对复合材料的玻璃化转变温度无明显影响,而且有利于复合材料热稳定性的提高;可反应烯键的引入提高了RPFEK与BMDM树脂的相容性与界面的粘接作用;与纯BMDM/DABPA树脂相比,10 % RPFEK增韧的BMDM/DABPA树脂的冲击强度从9.0 kJ/m2提高到了15.2 kJ/m2。     

BMI和BCE为基础的多元共聚热固性高性能基体树脂研究

用熔融预聚法对二苯甲烷双马来酰亚胺（BDM,即BMI）/二烯丙基双酚A（DABPA）和双酚A二氰酸酯（BCE）/溴化环氧树脂（BCE）各二元体系分别预聚再热混,制成溶解性、稳定性和反应性、粘接性好的多元共聚树脂。经阶梯式固化,并通过FTIR、DSC、DMA、TGA和SEM等手段测试了固化树脂的性能。结果表明,该树脂的玻璃化温度（Tg）为230.7℃,耐热指数（Z）为197℃,热膨胀系数（CTE）为7.0104×10-5/℃,介电常数ε为3.61,介电损耗tanδ（1MHz）为0.007,弯曲强度为131.83MPa,冲击强度25.0kJ/m2,氧指数为31,吸水率为0.44%。此耐热性、介电性能和力学性能等综合性能优异的阻燃型树脂适合做刚性覆铜板（CCL）和先进复合材料的高性能基体树脂。     

烯丙基酚氧树脂/双马来酰亚胺改性树脂的制备及表征

用环氧树脂和二烯丙基双酚A(DP)合成了3种新型烯丙基酚氧树脂,测试了该树脂改性双马来酰亚胺(BMI)树脂体系的力学性能和热性能及黏度特性,探讨了后处理对改性树脂性能的影响。结果表明,改性树脂具有良好的2韧性和耐热性,冲击强度达到了22.31kJ/m,HDT仍有224℃,后处理使得体系耐热性大大提高,韧性略有降低。     

萘酚改性烯丙基化环保型酚醛树脂的合成及研究

分别以环保型PF(酚醛树脂)和萘酚改性环保型PF为母体,成功合成了烯丙基化PF和萘酚改性烯丙基化PF,并制备了萘酚改性烯丙基化PF/BMI(双马来酰亚胺)共聚树脂;然后分别以上述树脂作为基体树脂,制备了玻璃纤维增强型复合材料。结果表明:当基体树脂为萘酚改性烯丙基化PF/BMI共聚树脂时,相应复合材料的冲击强度(321.6 kJ/m2)和弯曲强度(524.1 MPa)比萘酚改性烯丙基化PF基复合材料提高了11.0%和46.3%,比未改性环保型烯丙基化PF基复合材料提高了42.8%和258.2%,说明萘酚改性烯丙基化PF/BMI共聚树脂的增韧效果优于萘酚改性烯丙基化PF;萘酚改性烯丙基化PF/BMI共聚树脂基复合材料的耐热性能优于未改性烯丙基化PF体系,这是因为前者800℃时的残炭率(39.62%)高于后者(10.92%)所致。     

磷酸铝表面修饰及增强双马来酰亚胺复合材料性能

界面行为是决定聚合物基复合材料性能的重要因素之一。首先采用硅烷偶联剂和顺丁烯二酸酐对层状磷酸铝（LAP）逐步修饰制备出表面修饰LAP（m-LAP）；其次利用2，2''-二烯丙基双酚A（DABPA）扩链改性4，4''-双马来酰亚胺基二苯甲烷（BDM）得到双马来酰亚胺（BMI）树脂预聚体；最终利用机械共混法和热固化工艺制备了m-LAP/BMI复合材料。研究发现，m-LAP与BMI基体之间形成了连续、紧密、低缺陷的界面结合。与纯BMI相比，m-LAP/BMI-3.5复合材料的常温弯曲强度为173.37MPa，提高了15.14%；经300℃热处理6h后，m-LAP/BMI-3.5复合材料弯曲强度仍能保持常温强度的71.22%，远高于热处理后的纯BMI树脂及LAP/BMI复合材料；m-LAP/BMI复合材料的玻璃化转变温度（Tg）提高至234~240℃；m-LAP/BMI-3.5复合材料的介电常数达到4.46，介电损耗为0.05。因此，两步表面修饰法能够显著改善LAP/BMI复合材料的综合性能。     

乙烯基酯树脂改性双马来酰亚胺的研究

本工作用乙烯基酯树脂(VE树脂)与4,4'—二苯甲烷双马来酰亚胺(BMIM)预聚,得到了能溶于低沸点溶剂(丙酮)的改性树脂B。研究了不同配比的改性树脂的固化行为及固化物的耐热性。结果表明,在BMIM中加入VE树脂,改进了树脂的加工性能(降低了固化温度,改善了与增强纤维的复合能力),但同时也降低了固化树脂的耐热性。本工作还研究了改性树脂B与玻璃和碳纤维的复合工艺和复合材料的性能。结果表明,复合材料有高的冲击韧性,在250℃下仍有较高的强度保持率。     

三元共聚双马来酰亚胺树脂的制备与性能

按照马来酰亚胺基团和烯丙基基团物质的量比为1∶0.87将寡聚双马来酰亚胺(PPCBMI)与o,o′-二烯丙基双酚A(DABPA)和二苯甲烷型双马来酰亚胺(BDM)反应合成了新型三元共聚双马来酰亚胺树脂。采用示差扫描量热分析、热重分析、动态机械分析及力学性能测试研究了PPCBMI含量对树脂的固化行为,固化物的耐热性、动态热机械性能和力学性能的影响。结果表明,PPCBMI可以有效地增韧BDM/DABPA体系,由于引入了大体积的Cardo结构,获得了耐热性与韧性兼具的理想树脂。     

烯丙基酚醛改性双马来酰亚胺树脂的制备与性能

合成并表征了烯丙基酚醛树脂,再将其与双马来酰亚胺共聚制备了烯丙基酚醛改性双马树脂。通过DSC和FTIR分析了该树脂的固化行为,研究了其工艺性,利用TGA和DMA评价了其固化物的耐热性。结果表明,烯丙基酚醛树脂改性双马树脂可用于RTM等成型工艺,其固化物Tg约为330℃,初始热分解温度约400℃,5%失重温度达410℃,10%失重温度423℃。该树脂耐热性优异,可用作耐高温先进复合材料的基体树脂。     

聚酰胺酰亚胺对BMI/DP共聚树脂的增韧研究

以DP(二烯丙基双酚A)为BMI(双马来酰亚胺)的共聚改性剂,制备BMI/DP共聚树脂;然后以PAI(聚酰胺酰亚胺)为增韧改性剂,制备PAI增韧改性BMI/DP共聚树脂。研究结果表明:当w(PAI)=3%(相对于共聚树脂质量而言)时,改性树脂具有较好的增韧效果;此时,其冲击强度(11.81 kJ/m2)提高了19%以上,KIC(临界应力强度因子)值(1.45 MPa.m0.5)和GIC(临界应变能释放率)值(351.4 J/m2)均比增韧前提高了30%以上,表现出较好的断裂韧性,并且其断面为典型的韧性破坏;其Tg(玻璃化转变温度)达到了252.5℃,5%热失重温度仍超过405℃,说明其耐热性几乎没有下降。     

亚微米级β-SiC晶须改性三元BMI树脂体系的研究

将亚微米级碳化硅（β-SiC）晶须使用硅烷偶联剂进行表面处理,用处理的β-SiC晶须改性实验室制备的一种韧性三元双马来酰亚胺树脂体系（BDM/BPA-BMI/DABPA）。研究了β-SiC晶须用量对BDM/BMPP/DABPA三元体系性能的影响。结果表明,适量β-SiC晶须的加入可以有效提高固化树脂的拉伸模量和弯曲模量,并降低断裂伸长率;使用β-SiC晶须改性的树脂体系仍可保持较高的抗冲击性能和断裂韧性;固化树脂的最大分解速率对应的温度随着SiC晶须含量的增加而升高,最大分解速率随着SiC晶须含量的增加而减小,加入β-SiC晶须体系的玻璃化转变温度最大可以达到308℃,体系的耐热性能得到提高。     

Sapindaceae,cyanolipids, and bugs

Scentless plant bugs (Heteroptera: Rhopalidae) are so named because adults of the Serinethinae have vestigial metathoracic scent glands. Serinethines are seed predators of Sapindales, especially Sapindaceae that produce toxic cyanolipids. In two serinethine species whose ranges extend into the southern United States,Jadera haematoloma andJ. sanguinolenta, sequestration of host cyanolipids as glucosides renders these gregarious, aposematic insects unpalatable to a variety of predators. The blood glucoside profile and cyanogenesis ofJadera varies depending on the cyanolipid chemistry of hosts, and adults and larvae fed golden rain tree seeds (Koelreuteria paniculata) excrete the volatile lactone, 4-methyl-2(5H)-furanone, to which they are attracted.Jadera fed balloon vine seeds (Cardiospermum spp.) do not excrete the attractive lactone. Loss of the usual heteropteran defensive glands in serinethines may have coevolved with host specificity on toxic plants, and the orientation ofJadera to a volatile excretory product could be an adaptive response to save time.Mention of a commercial product does not consititute an endorsement by the USDA.     

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.     

Many Drugs of Abuse May Be Acutely Transformed to Dopamine,Norepinephrine and Epinephrine In Vivo

It is well established that a wide range of drugs of abuse acutely boost the signaling of the sympathetic nervous system and the hypothalamic–pituitary–adrenal (HPA) axis, where norepinephrine and epinephrine are major output molecules. This stimulatory effect is accompanied by such symptoms as elevated heart rate and blood pressure, more rapid breathing, increased body temperature and sweating, and pupillary dilation, as well as the intoxicating or euphoric subjective properties of the drug. While many drugs of abuse are thought to achieve their intoxicating effects by modulating the monoaminergic neurotransmitter systems (i.e., serotonin, norepinephrine, dopamine) by binding to these receptors or otherwise affecting their synaptic signaling, this paper puts forth the hypothesis that many of these drugs are actually acutely converted to catecholamines (dopamine, norepinephrine, epinephrine) in vivo, in addition to transformation to their known metabolites. In this manner, a range of stimulants, opioids, and psychedelics (as well as alcohol) may partially achieve their intoxicating properties, as well as side effects, due to this putative transformation to catecholamines. If this hypothesis is correct, it would alter our understanding of the basic biosynthetic pathways for generating these important signaling molecules, while also modifying our view of the neural substrates underlying substance abuse and dependence, including psychological stress-induced relapse. Importantly, there is a direct way to test the overarching hypothesis: administer (either centrally or peripherally) stable isotope versions of these drugs to model organisms such as rodents (or even to humans) and then use liquid chromatography-mass spectrometry to determine if the labeled drug is converted to labeled catecholamines in brain, blood plasma, or urine samples.     

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.     

2008～2009年世界塑料工业进展

收集了2008年7月～2009年6月世界塑料工业的相关资料,介绍了2008～2009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、环氧树脂、不饱和聚酯树脂)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。