ABS车用防撞护栏材料的制备及防撞机理研究

利用挤出-注塑成型方法制备了纳米CaCO3/钛酸钾晶须/丁腈橡胶/ABS汽车防撞护栏材料。通过正交设计方法对复合材料的配方进行了优化,并用扫描电镜观察其缺口冲击断面。结果表明:按最佳配方制备的复合材料的缺口冲击强度、弯曲弹性模量、弯曲和拉伸强度分别比纯ABS提高了39.8%、176%、79.3%和20.1%。其防撞机理表现为材料受到冲击时橡胶颗粒内部及表面产生空穴,伴之以空穴之间聚合物链的伸展和剪切而导致基体的形变,属典型的塑性变形。     

亚临界水挤出法制备ABS/木粉复合材料力学性能研究

在丙烯腈丁二烯苯乙烯共聚物（ABS）和木粉的熔融挤出共混过程中,通过引入湿态挤出和亚临界水挤出的方法,研究了挤出温度和添加助剂品种对ABS/木粉复合材料的丙酮抽提物红外光谱及复合材料力学性能的影响,对复合材料的试样断面形貌进行了考查。结果表明,在ABS与木粉的湿态挤出或亚临界水挤出条件下,水或高压水的溶胀作用促进了界面处木纤维与ABS或马来酸酐接枝ABS（ABS-g-MAH）的反应,提高了界面结合强度,从而使复合材料力学性能明显提升;在亚临界水的最佳挤出工艺配方条件下（200 ℃挤出,含ABS-g-MAH 5份）,ABS/木粉复合材料的拉伸强度、弯曲强度、缺口冲击强度及无缺口冲击强度分别达到45.3 MPa、72.4 MPa、1.5 kJ/m2和6.5 kJ/m2。     

PC/改性ABS复合材料的制备与性能

在传统的丙烯腈-丁二烯-苯乙烯共聚物(ABS)乳液接枝聚合中加入甲基丙烯酸甲酯(MMA),制得了改性ABS,然后与聚碳酸酯(PC)共混挤出，制得了PC/改性ABS复合材料。研究了MMA用量对PC/改性ABS复合材料的熔体流动速率(MFR)、维卡软化温度、力学性能的影响。结果表明：随着MMA用量的增加，PC/改性ABS复合材料的MFR、拉伸强度、弯曲强度和缺口冲击强度均先升高后降低。当MMA质量分数为20%时，PC/改性ABS复合材料的拉伸强度和弯曲强度均达到最大，分别为48.9 MPa和63.2 MPa;当MMA质量分数为30%时，PC/改性ABS复合材料的缺口冲击强度为41.0 kJ/m²;当MMA质量分数不高于30%时，与PC/ABS复合材料相比，PC/改性ABS复合材料的维卡软化温度更高。     

高填充油茶果壳基木塑复合材料的制备及力学性能

以油茶果壳和不同塑料即聚丙烯、高密度聚乙烯(PE-HD)、低密度聚乙烯、线性低密度聚乙烯为原料,采用模压成型的方法制备了高填充油茶果壳基木塑复合材料,利用电子万能试验机和悬臂梁冲击试验机测试其力学性能。通过单因素试验分析塑料种类对复合材料力学性能的影响,确定较优塑料种类后进一步优化制备参数。以壳粉含量、增容剂马来酸酐接枝聚乙烯(MAPE)含量、热压温度、热压时间为设计因素,以弯曲强度、弯曲弹性模量、拉伸强度、冲击强度为力学性能优化目标,设计L₉(3⁴)正交试验,研究了高填充油茶果壳基木塑复合材料的制备工艺,利用极差分析和方差分析得到了较优配方和工艺参数组合。研究表明：当添加塑料为PE-HD时,复合材料的弯曲强度最大为34.40 MPa,拉伸强度最大为18.20 MPa,力学性能较优;壳粉含量为65%时,添加7%MAPE的复合材料强度较好,弯曲强度最大为33.66 MPa;优化制备参数组合为壳粉含量55%,MAPE含量5%,热压温度160℃,热压时间10 min。     

长玻纤增强聚丙烯复合材料注塑成型工艺优化

通过熔融浸渍包覆工艺,制备玻纤含量为40%的长玻纤增强聚丙烯复合材料(LGFRPP)粒料,选择注塑温度、注射压力以及注射速率作为试验的3个因子,将拉伸强度、弯曲强度及冲击强度作为评价指标,利用正交实验设计的方法对LGFRPP的注塑成型工艺进行了优化研究,研究了各注塑工艺对力学性能的影响,得到最佳注塑成型条件。研究结果表明,对拉伸性能影响最显著的是注射速率,对弯曲性能影响最显著的是注塑温度,对冲击强度影响最显著的是注射压力;采用综合平衡原则,结合拉伸、弯曲和冲击性能,得到含量为40%的LGFRPP复合材料的最佳注塑成型条件为注塑温度250℃,注射压力40 MPa,注射速度60%。在最佳工艺条件下,材料的拉伸强度为132. 02 MPa,弯曲强度为200. 38 MPa,冲击强度为59. 34 k J/m2。     

用于FDM的蒙脱土改性PC/ABS合金丝材的性能

用有机改性后的蒙脱土(OMMT)对聚碳酸酯(PC)/丙烯腈-丁二烯-苯乙烯(ABS)合金进行增容改性,测试合金的力学性能、维卡软化点、熔体流动速率等性能,并对测试结果进行分析讨论。发现当PC∶ABS质量比=70∶30,OMMT质量分数为3%时,综合力学性能最好,拉伸强度为67. 21 MPa,弯曲强度为80. 90 MPa,缺口冲击强度为17. 35 k J/m~2,均优于纯PC/ABS合金的力学强度。将PC/ABS/OMMT合金用3D打印耗材挤出机挤出成直径为(1. 75±0. 25) mm的丝材,当OMMT质量分数为3%时,丝材成型性最佳。最后用熔融沉积成型的方法打印合金,比较熔融沉积成型与传统注塑成型制品的力学性能差异。熔融沉积成型试样保持了较好的拉伸强度和弯曲强度,达注塑成型的60%多,但是断裂伸长率和抗缺口冲击强度较差。     

PVC/ABS合金材料注塑加工的性能研究

研究了注塑级聚氯乙烯(PVC)/丙烯晴-丁二烯-苯乙烯(ABS)合金的加工流变性能.该合金采用挤出造粒、注射成型的方式制备,探讨了不同配比下合金力学性能、耐热性、相容性以及毛细管流变性能的变化.结果表明:PVC/ABS合金是半相容结构;合金的拉伸强度随着PVC用量的降低呈下降的趋势;PVC/ABS的质量比为40/60时合金的相容性最好,冲击强度最高;合金的弯曲强度和弯曲模量都随着合金中ABS用量的升高而下降.合金的耐热性随着PVC/ABS合金中ABS用量的增大而升高.PVC/ABS的质量比为20/80时合金的流动性最好.     

挤出工艺对纳米碳酸钙母料性能影响

采用纳米碳酸钙(nano-CaCO_3),分别以一字排列三螺杆挤出工艺与双转子连续混炼挤出工艺制备nano-CaCO_3母料,然后添加到高密度聚乙烯(PE-HD)中制备PE-HD/nano-CaCO_3复合材料。分析了不同挤出工艺对PE-HD/nano-CaCO_3复合材料断面形貌和力学性能的影响。结果表明,一字排列三螺杆挤出工艺更好地改善了nano-CaCO_3在PE-HD中的分散性,提高了PE-HD/nano-CaCO_3复合材料的韧性,使其缺口冲击强度提高63.8%,对断裂伸长率影响较小,降低了16.4%;双转子连续混炼挤出工艺更好地改善了PE-HD/nano-CaCO_3复合材料的弯曲性能,使其弯曲强度提高6.0%,弯曲弹性模量提高48.4%,对拉伸强度影响较小,降低了5.3%。     

ABS/PA6复合材料的力学性能影响研究

制备了一系列ABS/PA6复合材料,并探讨了不同增容剂、不同种类ABS以及不同增韧剂对ABS/PA6复合材料力学性能的影响。结果表明,马来酰亚胺(MS-NB)对ABS/PA6的增容效果最佳,当添加量为5%时,缺口冲击强度由4.4 k J/m~2提高到7.8 k J/m~2,提升幅度为77%。在缺口冲击强度表现上,具有核壳结构的MBS增韧剂明显优于高胶粉;不同ABS种类的ABS在该体系中力学性能差异很大,高胶含量的ABS树脂能显著提高复合材料的缺口冲击强度,但弯曲强度,弯曲模量等性能有一定程度下降。     

ABS/OMMT、PA6/OMMT复合材料形态及性能

熔融挤出制备了有机蒙脱土(OMMT)含量不同的ABS/OMMT,PA6/OMMT复合材料,用X射线衍射仪(XRD)、透射电子显微镜(TEM)等仪器研究OMMT分别在ABS、PA6基体中的分布情况及对其力学性能的影响.结果表明:在ABS/OMMT复合材料中,OMMT主要为插层结构,大部分OMMT片层以聚集状态存在;而对PA6/OMMT复合材料,OMMT片层主要以剥离形态分布在PA6基体相中;随着OMMT含量增加,ABS/OMMT复合材料的拉伸、弯曲强度及弯曲模量都先上升后下降,且当OMMT含量在3份时性能较好,其缺口冲击强度呈下降趋势;PA6/OMMT复合材料在OMMT含量为3份时,其拉伸、弯曲强度和弯曲模量都出现极值现象,而缺口冲击强度线性降低.由于OMMT与PA6有较好的亲和力,在PA6中分散性较好,使PA6/OMMT复合材料的综合力学性能比ABS/OMMT复合材料的优异.     

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.