EVA含量对HDPE和EVA共混接枝马来酸酐粘接树脂粘接性能的影响

制备了乙烯-醋酸乙烯酯共聚物(EVA)和高密度聚乙烯(HDPE)共混接枝马来酸酐(MAH)共混物。首先考察了不同含量EVA的加入对HDPE接枝MAH粘接树脂粘接性能的影响。进一步采用哈克转矩流变仪、傅立叶变换红外光谱仪、流变仪、差示扫描量热仪和视频光学接触测量仪等手段研究了EVA含量为10份时粘接树脂的性能。结果表明,将10份EVA与HDPE共混后,再以MAH进行接枝改性,可使树脂的粘接强度明显提升。EVA的加入使色散分量、润湿性和弹性都有一定提高,更有利于粘接。     

CPP/MAH接枝共聚物合成及粘接性能研究

用马来酸酐 (MAH)对氯化聚丙烯 (CPP)进行接枝共聚 ,通过 1R分析证明马来酸酐与氯化聚丙烯发生了接枝共聚反应 ,考察了不同条件下制得的CPP/MAH接枝共聚物胶粘剂对聚烯烃材料的粘接性能 ,结果表明CPP/MAH共聚物胶粘剂对聚烯烃材料具有较好的粘接性能。     

HDPE接枝MAH配方的研究

制备了高密度聚乙烯(HDPE)接枝马来酸酐(MAH)粘接树脂,并分析不同工艺对于体系接枝率的影响。结果表明,马来酸酐(MAH)的含量、过氧化二异丙苯(DCP)含量、苯乙烯含量、基体树脂熔体质量流动速率均会对体系接枝率产生影响。加工温度190℃、反应时间8 min时,添加1.5 phr的MAH、0.1 phr的DCP、1.5 phr的苯乙烯,基体的熔体质量流动速率为8 g/10min的情况下,体系接枝率达到最大值。     

HDPE接枝马来酸酐粘接树脂熔融接枝工艺的研究

制备了高密度聚乙烯(HDPE)接枝马来酸酐(MAH)粘接树脂,进一步对接枝工艺进行研究。结果表明,MAH的含量、过氧化二异丙苯(DCP)的含量、共混时间都会对粘接效果产生影响。共混时间为8 min时,接枝反应已经很充分;当添加1.5份MAH和0.1份DCP时,接枝率达到最大值0.815%,此时综合粘接效果最好。     

聚烯烃弹性体与马来酸酐的熔融接枝

以双螺杆挤出机作为反应器，比较了聚烯烃弹性体（POE），线性低密度聚乙烯（LLDPE）与马来酸酐（MAH）的熔融接枝反应。尽这两种树脂具有相近的支化度，但由于POE树脂的大支链对大分子自由基之间的偶合反应具有抑制作用，所以，POE/MAH接枝体系的接枝率明显高于LLDPE／MAH接枝体系，而且接枝产物保持了较好的流动性；酸酐在POE树脂上的接枝率随过氧化物和接枝单体用量的增加而增大。接枝树脂可以明显提高PE与铝之间的粘接强度。     

马来酸酐接枝废旧 HDPE的制备与应用

以马来酸酐(MAH)为单体、过氧化二异丙苯(DCP)为引发剂,用熔融接枝法制得改性废旧HDPE(MARPE),研究DCP、MAH含量对接棱产物性能的影响,用红外光谱(FIIR)对接枝产物进行分析,并将接枝产物用于废旧PC/ABS合金,用SEM观察界面.结果表明:马来酸酐能够在废旧HDPE上进行接枝;随着DCP含量的增加,接枝产物的接枝率逐渐增加,熔体指数减小;随着MAH含量的增加,接枝产物的接枝率先增加后减小,熔体指数无明显变化;马来酸酐接枝废旧HDPE能够提高废旧PC/ABS合金的界面相容性,改善其力学强度.     

CPP/MAH/AN接枝共聚物合成及粘接性能研究

以甲苯为溶剂，以过氧化苯甲酰（BPO）为引发剂，用马来酸酐（MAH）和丙烯腈（AN）对氯化聚丙烯（CPP）进行接枝共聚改性，考查了不同条件下制得的CPP／MAH／AN接枝共聚物胶粘剂对聚烯烃材料的粘接性能。结果表明CPP／MAH／AN共聚物胶粘剂对聚丙烯具有较好的粘接性能，剪切强度达到2．46MPa，对聚乙烯的粘接达到0．5MPa。     

给水用钢丝增强聚乙烯复合管道粘接树脂的研究

利用反应性接枝和物理共混两种技术,制备了一种适合于粘接聚烯烃树脂和金属铜的粘接树脂。主要研究了反应性接枝配方和物理共混配方对树脂粘接性能的影响。采用接触角、扫描电子显微镜、能谱等表征和测试手段,对最终的接枝树脂和粘接树脂的极性、粘接性能进行了研究。结果表明,聚乙烯接枝马来酸酐(PE-g-MAH)的最佳配方为:线型低密度聚乙烯90份,高密度聚乙烯10份,马来酸酐1.5份,过氧化二异丙苯0.08份,抗氧剂1010和抗氧剂168分别为0.2份。最高接枝温度为180℃。粘接树脂的最佳配方为:PE-g-MAH 100份,增粘树脂6份,调节剂15份。研制的粘接树脂具有和聚烯烃一样的加工性能和条件,同时表现出极佳的粘接性能,主要用于给水用钢丝增强聚乙烯复合管道。     

PEW-g-MAH/St的制备及其在UHMWPE纤维表面改性上的应用

制备马来酸酐/苯乙烯接枝聚乙烯蜡(PEW-g-MAH/St),并使用其对UHMWPE纤维进行涂层改性处理,以提高纤维与树脂基体的界面黏接强度。分别研究与分析了MAH接枝率以及纤维拔出强度的影响因素。结果表明:随着马来酸酐(MAH)用量的增加,MAH接枝率随之逐渐增加;随着苯乙烯(St)用量的增加,MAH接枝率呈先增加后保持不变的趋势;红外分析表明MAH与St已被成功接枝到PEW大分子上;改性处理前后纤维的拉伸性能和结晶性能没有发生明显变化,但纤维的拔出强度和浸润性得到显著改善。     

铝塑复合板用热熔胶的制备及性能研究

以过氧化二异丙苯(DCP)为引发剂、马来酸酐(MAH)为接枝改性单体和聚乙烯(PE)为主要原料,采用熔融挤出法制备了铝塑复合板用PE-g-MAH(聚乙烯接枝马来酸酐)基HMA(热熔胶),并着重探讨了DCP和MAH含量对PE-g-MAH的接枝效率和粘接性能等影响。结果表明:在试验范围内,PE-g-MAH的接枝效率(y)与DCP含量(x1)或MAH含量(x2)之间的关系符合y=28.03x1+1.49或y=0.73x2+10.65的线性关系;当w(DCP)=0.44%、w(MAH)=2%时,PE-g-MAH基HMA的粘接性能相对最好,其剪切强度(6.10 MPa)高于杜邦HMA(4.26 MPa),并且其接枝效率为12.91%。     

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.     

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.     

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。     

Inorganic/organic nanocomposite coatings: The next step in coating performance

Inorganic/organic hybrid materials have considerable promise and are beginning to become a major area of research for many coating usages, including abrasion and corrosion resistance. Our primary approach is to prepare the inorganic phase in situ within the film formation process of the organic phase. The inorganic phase is introduced via sol-gel chemistry into a thermosetting organic phase. By this method, the size, periodicity, spatial positioning, and density of the inorganic phase can be controlled. An important aspect of the inorganic/organic hybrid materials is the coupling agent. The initial task of the coupling agent is to provide uniform mixing of the oligomeric organic phase with the sol-gel precursors, which are otherwise immiscible. UV-curable inorganic/organic hybrid systems have the advantages of a rapid cure and the ability to be used on heat sensitive substrates such as molded plastics. Also, it is possible to have better control of the growth of the inorganic phase using UV curing. It is our ultimate goal to completely separate the curing of inorganic and organic phases to gain complete control over the morphology, and hence optimization of “all” the coating properties. Thus far, it has been found that concomitant UV curing of the inorganic and organic phases using titanium sol-gel precursors afforded nanocomposite coatings which completely block the substrate from UV light while maintaining a transparent to visible light. Also, it has been found that the morphology of the inorganic phase is highly dependent on the concentration and reactivity of the coupling agent. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004, in Chicago, IL.