正交设计在改性纳米CaCO3/PVC复合体系中的应用

选择不同的方法对纳米CaCO3进行表面改性,研究了表面处理剂对CaCO3/PVC纳米复合材料界面结合强度、力学性能及加工性能的影响。通过正交实验设计得到了力学性能最佳时的制备条件:表面处理剂选用钛酸酯偶联剂,其用量4%(质量分数),纳米CaCO3用量15%(质量分数)。极差分析结果表明,对冲击强度而言,主要影响因素为表面处理剂用量;扫描电镜显示,钛酸酯偶联剂处理可使纳米CaCO3颗粒在PVC基体中达到良好分散,并提高其界面结合强度;流变性能研究表明,经钛酸酯处理的纳米CaCO3填充PVC具有更低的平衡转矩。     

聚丙烯/轻质CaCO_3复合材料的力学性能研究

采用熔融共混的方法制备了PP/CaCO3复合材料,并研究了轻质CaCO3的表面处理、含量及粒径对材料的拉伸强度和缺口冲击强度两大主要力学性能的影响,着重对实验结果作了科学的理论分析。实验结果表明,钛酸酯类偶联剂能很好地改善CaCO3粒子与PP基体的界面相容性,从而使复合材料的力学性能提高;经表面处理后的超细轻质CaCO3(纳米级)所填充复合材料的拉伸强度和缺口冲击强度明显优于普通轻质CaCO3(微米级);而且处理后的纳米级CaCO3在填充量为10%时对PP的增强增韧效果最佳。     

供水管用改性聚丙烯/纳米CaCO3复合材料的研究

以改性聚丙烯(PP)为基体、纳米CaCO3为填料，采用直接分散法及两步混炼工艺制备了供水管用改性PP／纳米CaCO3复合材料。阐述了纳米CaCO3的表面处理、钛酸酯偶联剂含量、纳米CaCO3含量及不同混合工艺对纳米复合材料性能的影响。同时对改性PP／纳米CaCO3复合材料及其供水管材的制备工艺进行了分析讨论，确定了改性PP／纳米CaCO3复合材料的配方及其成型工艺参数，并与国内外相关产品的性能进行了比较。     

纳米CaCO3/PP复合材料的制备与性能研究

分别采用钛酸酯偶联剂、硅烷偶联剂、铝酸酯偶联剂等对纳米CaCO3进行表面处理,通过熔融共混法制备了纳米CaCO3/PP复合材料,并进行了力学性能测试与表征.结果表明,经过三种偶联剂处理后的纳米CaCO3能显著提高PP的缺口冲击韧性,其中NDZ-201钛酸酯偶联剂的处理效果最佳,当纳米CaCO3质量分数为7%时,对PP的改性效果最好,缺口冲击韧性提高了38%,弯曲模量提高了33%.     

偶联剂NDZ-105用量对PP/CaC03复合材料性能与形态的影响

采用经钛酸酯偶联剂NDZ-105处理的CaCO3与PP在双螺杆挤出机中熔融混合后制备PP/CaCO3复合材料.研究偶联剂NDZ-105用量对PP/CaCO3复合材料力学性能、结晶性能与断面形态的影响.研究结果表明:随着偶联剂NDZ-105用量的增加,PP/CaCO3复合材料的拉伸强度、弯曲强度和结晶温度逐渐下降,而断裂伸长率从65.2%提高到134.5%,冲击强度从6.1 MPa增加到8.8 MPa.     

纳米CaCO3对LLDPE/POE/mPE力学性能影响

采用不同种类及用量的偶联剂活化纳米碳酸钙(CaCO3)，并以熔融共混方法制备了LLDPE(线性低密度聚乙烯)／POE(聚烯烃类弹性体)／mPE(茂金属聚乙烯)／纳米CaCO3复合材料，对该体系的力学性能进行了系统研究。结果表明，3．5％(质量分数，下同)的硼酸酯偶联剂SB-99可对纳米CaCO3起到良好的活化作用，随活化纳米CaCO3的加入，复合材料的拉伸强度与断裂伸长率呈峰形变化，且在纳米CaCO3含量为5％左右时达到最大值。     

纳米CaCO3改性β成核聚丙烯的研究

采用经铝钛复合偶联剂处理的纳米CaCO3粒子对β成核聚丙烯（β-PP）进行改性，研究了pPP／纳米CaCO3复合材料的力学性能。结果表明，添加纳米CaCO3能够提高β-PP的综合力学性能，在纳米CaCO3用量为4％（质量分数，下同）时，冲击强度比β-PP提高了33％，是纯PP的3倍；拉伸模量、弯曲模量分别比β-PP提高了10％和15％。X射线衍射和偏光显微镜对β-PP／纳米CaCO3复合材料的结晶结构表征表明，添加纳米CaCO3可以提高β-PP的β晶含量。降低晶粒尺寸，但不会改变β-PP的束状结晶结构形态；差示扫描量热分析表明，纳米CaCO3粒子的存在降低了β-PP的结晶温度和结晶速率。     

PP／GF／纳米CaCO3复合材料的加工与性能研究

采用熔融共混方法制备了纳米碳酸钙/玻纤/聚丙烯(纳米CaCO3/GF/PP)复合材料,探讨了纳米复合材料的配方、生产工艺及纳米CaCO3对复合材料力学性能的影响.结果表明:纳米CaCO3对玻纤增强聚丙烯具有增强增韧作用;采用稀土复合偶联剂对纳米CaCO3进行表面活化处理,添加适量增容剂,对提高复合材料的力学性能具有较好的效果;添加3%的纳米CaCO3后复合材料的综合力学性能最好.     

PP／纳米CaCO3发泡板材的性能和泡孔结构的研究

利用纳米CaCO3对聚丙烯（PP）的增强增韧作用，采用合理的成型工艺及设备，挤出成型了性能优越的发泡板材。详细研究了CaCO3粒子对板材力学性能的影响，研究表明：纳米CaCO3粒子的含量接近4％时（相对PP），粒子在基体中的分散良好，复合材料的拉伸强度和冲击强度达到最大值；纳米粒子是否经过表面处理，只对材料冲击强度的影响产生不同效果；微米CaCO3粒子含量小于5％时（相对PP），对板材的性能影响很小，但超过该含量后，板材的性能明显下降。     

聚丙烯/水相法改性纳米碳酸钙复合材料的结构与性能

用三官能团的有机改性剂对纳米碳酸钙进行表面改性，填充到聚丙烯中，制得PP／纳米CaCO3复合材料，同时对复合材料的力学性能、微观形态以及热性能进行研究。结果表明：PP／改性纳米CaCO3复合材料的力学性能及热性能都有较大幅度的改善。改性剂与纳米CaCO3形成化学结合，改性纳米CaCO3对PP有异相成核的作用，能诱导口晶型PP的产生，在提高复合材料强度的同时，使韧性明显提高。     

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.     

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。