LLDPE/LDPE共混物的结构与性能

以线型低密度聚乙烯(LLDPE)与低密度聚乙烯(LDPE)为原料,按m(LLDPE)∶m(LDPE)=75∶25共混,经挤出机熔融吹膜制备了LLDPE/LDPE薄膜。采用差示扫描量热仪、凝胶渗透色谱仪、电子万能试验机、雾度仪和旋转流变仪等研究了LLDPE,LDPE,LLDPE/LDPE共混物的结晶行为、流变行为、热性能以及所制薄膜的力学性能、光学性能等,并简要分析了其各项性能得到改善的原因。结果发现:LLDPE/LDPE薄膜具有较好的综合力学性能、光学性能、加工性能。     

双峰分布茂金属聚乙烯共混的研究

用双峰分布茂金属聚乙烯(mPE)与两种普通聚乙烯(LLDPE，LDPE)进行共混，并吹塑成薄膜，测定了薄膜的力学性能和流变性能。结果发现：在mPE中加入质量分数为20％的LLDPE(LDPE)后，薄膜的拉伸强度、撕裂强度和穿刺强度都只有轻微的变化，LLDPE／mPE薄膜的拉伸强度几乎没有降低，甚至穿刺强度还高于纯mPE；加入量在20％-80％之间时，穿刺强度和撕裂强度几乎没有变化。LDPE对mPE的流动性有显著改善。     

茂金属聚乙烯与普通聚乙烯共混研究

用一种双峰分布茂金属聚乙烯(mPE)与普通聚乙烯(LLDPE或LDPE)共混料吹塑薄膜，测定mPE对薄膜力学性能的影响。结果表明，在LLDPE(LDPE)中加入20％mPE制成共混料，其吹塑薄膜的拉伸强度和撕裂强度均提高20％，穿刺强度提高60％(100％)；另外发现，当在LLDPE(LDPE)中加入20％～80％mPE时，薄膜的穿刺强度和撕裂强度几乎没有变化。     

LDPE与LLDPE共混树脂薄膜的研究

将线性低密度聚乙烯(LLDPE)与低密度聚乙烯(LDPE)经过熔融共混、挤出吹制得一系列薄膜。分析了共混树脂的流变性能,研究了共混树脂的结晶性能,讨论了薄膜的力学性能和热稳定性能。结果表明:纯树脂和共混树脂熔体都是假塑性流体,通过升温同样可以降低共混树脂的表观黏度,共混树脂薄膜的力学性能优于纯LDPE薄膜,LDPE质量分数为70%的薄膜热稳定性最佳。     

改性纳米ZnO/LLDPE/LDPE复合薄膜的性能研究

采用熔融共混法在线型低密度聚乙烯（LLDPE）／低密度聚乙烯（LDPE）复合体系中添加纳米ZnO，制成纳米ZnO／LLDPE／LDPE复合薄膜。采用偏光显微镜、扫描电子显微镜、差示扫描量热法、MIC法，研究了纳米ZnO改性LLDPE／LDPE复合薄膜的力学和光学性能。结果表明，纳米ZnO在薄膜中呈现出良好的分散水平，平均粒径在100mm以下。纳米ZnO在LLDPE／LDPE复合体系的结晶过程中，可起到明显的诱导成核作用，使球晶尺寸细化且数量增多，但复合体系的结晶度无明显变化。该薄膜的综合性能明显提高。     

醇盐水解沉淀法制备的SiO2-W-SYJ应用于PE薄膜及其性能的研究

采用醇盐水解沉淀法制备出粒度为40 nm、颗粒均匀的球型SiO2.W-SYJ.采用熔融共混法在线型低密度聚乙烯(LLDPE)/低密度聚乙烯(LDPE)复合体系中添加纳米SiO2-W-SYJ制成SiO2-W-SYJ/LLDPE/LDPE复合薄膜.采用TEM电镜、万能力学实验机、MIC法,研究了复合薄膜的力学性能、光学性能和抗菌性能.结果表明:该薄膜除了具有良好的力学和光学性能,突出表现出优异的抗菌性能.     

LLDPE/LDPE/TiO2复合膜的分散及光学性能

讨论了纳米TiO2在线型低密度聚乙烯（LLDPE），低密度聚乙烯（LDPE）复合体系中的分散和体系流变行为，研究了复合薄膜的光学性能。结果表明，以高流动性LDPE为基体的纳米TiO2母料，加入LLDPE，LDPE体系中后。复合体系的表观粘度有所提高。但拉伸粘度显著下降。纳米TiO2母料在LLDPE／LDPE复合体系中具有良好的分散性，复合薄膜中的纳米TiO2为一次粒子。纳米TiO2起到了异相成核剂的作用。球晶的粒子得到细化。在本研究的纳米填充范围内（质量分数不大于1.0％），复合薄膜的透光度基本不变。雾度发生了较大幅度上升，复合薄膜在紫外光区域的吸收显著增强。     

制定LLDPE和LDPE共混料的配方设计出质量更好的薄膜

<正> ——低密度聚乙烯薄膜的主要性能,韧性和牵伸性是随着线形低密度聚乙烯的加入而得到显著改进—— 将线形低密度聚乙烯(LLDPE)混入常用的LDPE中,所生产的薄膜要比LDPE为基本树脂的薄膜韧性和熔体牵伸性方面有所改善(改善程度取决于LLDPE含量)。可在     

口模间隙对聚乙烯挤出吹塑薄膜性能的影响

分别用间隙为1,2 mm的口模做低密度聚乙烯(LDPE)和线型低密度聚乙烯(LLDPE)的挤出吹塑薄膜试验,测试了薄膜的撕裂强度和雾度。结果表明:口模间隙对吹塑薄膜的影响不同。窄(即小间隙)口模得到的LLDPE薄膜的雾度和横、纵向撕裂强度均优于宽口模(即大间隙),因此,窄口模适合生产LLDPE吹塑薄膜;宽口模得到的LDPE薄膜的雾度、透光率及撕裂强度在适当的条件下优于窄口模,因此,宽口模适合生产LDPE吹塑薄膜。     

聚乙烯流延薄膜性能的影响因素分析

介绍了流延工艺及其所用聚烯烃材料的种类。以低密度聚乙烯(LDPE)、线型低密度聚乙烯(LLDPE)为基料,制备了不同配方的聚乙烯流延薄膜并对比了其性能,研究了不同流延工艺条件对流延薄膜性能的影响。结果表明:LLDPE含量的增加能够提高薄膜力学性能,而LDPE能改善薄膜的光学性能;提高模头温度可以使薄膜横向拉伸断裂应力增加,纵向性能相反,薄膜光学性能提高,热封温度降低;增加牵伸比,薄膜光学性能降低;提高流延辊温度,流延薄膜横向拉伸断裂应力下降,纵向拉伸断裂应力增加,光学性能下降,热封温度提高。     

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.     

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.     

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。     

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.     

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.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Some Large Wood-Boring Beetles in Southeastern USA

Ethanol and α-pinene were tested as attractants for large wood-boring pine beetles in Alabama, Florida, Georgia, North Carolina, and South Carolina in 2002–2004. Multiple-funnel traps baited with (−)-α-pinene (released at about 2 g/d at 25–28°C) were attractive to the following Cerambycidae: Acanthocinus nodosus, A. obsoletus, Arhopalus rusticus nubilus, Asemum striatum, Monochamus titillator, Prionus pocularis, Xylotrechus integer, and X. sagittatus sagittatus. Buprestis lineata (Buprestidae), Alaus myops (Elateridae), and Hylobius pales and Pachylobius picivorus (Curculionidae) were also attracted to traps baited with (−)-α-pinene. In many locations, ethanol synergized attraction of the cerambycids Acanthocinus nodosus, A. obsoletus, Arhopalus r. nubilus, Monochamus titillator, and Xylotrechus s. sagittatus (but not Asemum striatum, Prionus pocularis, or Xylotrechus integer) to traps baited with (−)-α-pinene. Similarly, attraction of Alaus myops, Hylobius pales, and Pachylobius picivorus (but not Buprestis lineata) to traps baited with (−)-α-pinene was synergized by ethanol. These results provide support for the use of traps baited with ethanol and (−)-α-pinene to detect and monitor common large wood-boring beetles from the southeastern region of the USA at ports-of-entry in other countries, as well as forested areas in the USA.