橡胶再生剂De-link在废轮胎胶粉增韧废PP复合材料中的应用研究

为了改善废轮胎胶粉(GRT)增韧废PP复合材料的力学性,用橡胶再生剂De-link对废胶粉进行改性再生.结果表明,加入3份再生剂De-link,可使废PP/GRT复合材料的冲击强度和拉伸强度有很大的提高;复合材料的冲击断面扫描电镜分析显示,经再生剂改性后复合材料的分散相尺寸明显减小,相容性显著提高.     

橡胶再生剂与相容剂并用在废轮胎胶粉增韧废PP复合材料中的应用研究

进行了橡胶再生剂与相容剂并用在废轮胎胶粉(GRT)增韧废PP复合材料中的应用研究.结果表明,采用橡胶再生剂De-link/相容剂CA并用改性GRT/废PP复合材料的冲击强度可达22.6KJ@m-2,比简单GRT/废PP共混体系提高了2.4倍,比废PP体系提高了2倍;拉伸强度则比简单GRT/废PP共混体系提高了30%,为废PP体系的87%;再生剂通过改变胶粉的交联度来提高复合材料的韧性,相容剂主要通过改善界面性能和提高相容性来提高复合材料的力学性能.     

改性胶粉在废旧苯乙烯类混杂塑料中的应用研究

研究了采用不同方法对精细胶粉(GRT)进行改性,并应用于废旧苯乙烯类混杂塑料(WPS)中,详细讨论了改性精细胶粉的用量对于复合材料体系拉伸强度、冲击强度等力学性能的影响。测试结果表明,对于不同改性方法制备的改性胶粉,均是在WPS中用量为5份时,所得复合材料的综合性能较好。其中,De link再生剂与SBR并用改性胶粉与WPS复合材料的拉伸强度为最高,为基体WPS的88 2%,较之未改性WPS/GRT提高了51 5%;羧基丁苯胶乳、引发剂BPO和偶联剂A 174并用改性胶粉/废旧苯乙烯类混杂塑料的冲击强度最高,比废塑料基体提高了43 3%,比未改性GRT/WPS复合材料提高了2 5倍。扫描电镜测试分析表明,胶粉改性可有效改善其与塑料基体间的界面粘合。     

废胶粉填充改性PP复合材料

采用熔融挤出共混的方法,选用三种废胶粉填充聚丙烯(PP),制备了PP/废胶粉复合材料,研究了废胶粉质量分数对复合材料力学性能的影响.结果表明:废旧三元乙丙橡胶粉可明显提高复合材料冲击强度和拉伸断裂应变,当其质量分数为60%时,简支梁缺口冲击强度可提高33%,拉伸断裂应变增大了26%,有显著的增韧效果:废旧杂胶粉的加入使...     

废聚丙烯/废轮胎胶粉/废尼龙短纤维复合材料 Ⅰ.配方

用双螺杆挤出机制备了废聚丙烯/废轮胎胶粉/废尼龙短纤维(WPP/GRT/WSF)复合材料,通过正交实验得出了制备该复合材料的最佳配方,讨论了增容剂用量、氯化聚丙烯的含氯质量分数、GRT用量及其粒径、WSF用量及预处理对该复合材料力学性能的影响。结果表明,制备该复合材料的最佳配方(质量份,下同)是WPP100,GRT30,WSF8,二甲基二硫代氨基甲酸锌、二硫化二苯并噻唑、多乙烯多胺及重油用量依次为0.6,1.2,0.3,2,聚丙烯接枝马来酸酐、氯化聚丙烯用量依次为8,4;在最佳配方下,该复合材料的非缺口冲击强度为25.2kJ/m2,拉伸强度为13.6MPa;GRT用量为30份时,该复合材料的拉伸强度和非缺口冲击强度最大,GRT的最佳粒径为40目;WSF经D法预处理后,提高了该复合材料的力学性能,拉伸强度为16.3MPa,非缺口冲击强度为27.8kJ/m2。     

废聚丙烯/废轮胎胶粉/废尼龙短纤维复合材料I.配方

用双螺杆挤出机制备了废聚丙烯／废轮胎胶粉／废尼龙短纤维(WPP／GRT／WSF)复合材料,通过正交实验得出了制备该复合材料的最佳配方,讨论了增容剂用量、氯化聚丙烯的含氯质量分数、GRT用量及其粒径、WSF用量及预处理对该复合材料力学性能的影响。结果表明,制备该复合材料的最佳配方(质量份,下同)是WPP100,GRT30,WSF8,二甲基二硫代氨基甲酸锌、二硫化二苯并噻唑、多乙烯多胺及重油用量依次为0.6,1.2,0．3,2,聚丙烯接枝马来酸酐、氯化聚丙烯用量依次为8.4;在最佳配方下,该复合材料的非缺口冲击强度为25.2kJ／m^2,拉伸强度为13．6MPa;GRT用量为30份时,该复合材料的拉伸强度和非缺口冲击强度最大,GRT的最佳粒径为40目;WSF经D法预处理后,提高了该复合材料的力学性能,拉伸强度为16．3MPa,非缺口冲击强度为27．8kJ／m^2。     

回收高密度聚乙烯/废胶粉热塑性弹性体的制备

废胶粉经再生改性后,与回收高密度聚乙烯通过动态硫化法制得回收高密度聚乙烯/废胶粉热塑性弹性体.研究了橡塑比、De-link橡胶再生剂和增容剂EVA的用量对热塑性弹性体力学性能的影响,并通过扫描电镜观察了弹性体的微观结构.实验结果表明:橡塑比为40/60、D-link再生剂为2～4份、EVA为5份时,弹性体的综合性能较优,同时两相相容性良好.     

废聚丙烯/废轮胎胶粉/废尼龙短纤维复合材料Ⅱ.工艺条件

采用反应挤出方法制备了废聚丙烯／废轮胎胶粉／废尼龙短纤维(WPP／GRT／WSF)复合材料,讨论了螺杆转速、机头温度对WPP／GRT／WSF复合材料力学性能的影响。结果表明,当螺杆转速为15r／min,机头温度为185～195℃时,WPP／GRT／WSF复合材料的力学性能达到最佳,拉伸强度为13．6MPa,冲击强度为25．2kJ／m^2。按照最佳配方和工艺挤出管材的拉伸强度为4,6MPa,冲击强度为5．4kJ／m^2,爆破压力为0．69MPa。     

三元乙丙橡胶硫化胶粉改性聚丙烯的研究

采用三元乙丙橡胶（EPDM）与EPDM硫化胶粉复合作为聚丙烯（PP）抗冲改性剂,研究了EPDM硫化胶粉和交联剂DCP用量对PP复合材料性能的影响。结果表明,PP复合材料的拉伸强度和弯曲强度随着硫化胶粉含量的增加而提高,冲击强度明显改善;而DCP用量增加对PP复合材料的拉伸强度和弯曲强度产生不利影响,少量DCP有助于提高PP复合材料的冲击强度;由DSC分析可知,硫化胶粉使PP熔体的结晶温度明显提高。     

“重油”与苯乙烯共聚改性胶粉增韧废PP复合材料的研究

用“重油”与苯乙烯共聚改性胶粉增韧废ＰＰ。探讨了２种共聚单体的摩尔比和单体与胶粉的配比对共聚反应的影响以及单体与胶粉配比和改性胶粉用量对复合材料力学性能的影响。研究表明：共混可强化未反应的剩余单体的聚合;当“重油”与苯乙烯摩尔比为１、改性胶粉与单体用量相同、１００份废ＰＰ中加入２０份改性胶粉时,复合材料的抗冲击强度比废ＰＰ提高了１倍,拉伸强度为废ＰＰ的７９３％。冲击断面ＳＥＭ及ＴＥＭ观察表明,改性胶粉与废ＰＰ界面相容性良好。     

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。