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复合材料的力学性能,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,相容性显提高。     

马来酸酐接枝胶粉对胶粉/HDPE共混材料影响的研究

探讨了胶粉(GRT)和高密度聚乙烯(HDPE)共混时胶粉的粒径、相容剂以及马来酸酐接枝胶粉(GRT-g-MAH)的用量对GRT/HDPE共混物力学性能的影响.用热分析以及扫描电子显微镜对共混材料的热行为以及形貌进行了分析.结果表明:制备GRT/HDPE复合材料时,胶粉的粒径越小,所得材料的拉伸性能越好,添加相容剂可进一步改善共混材料的性能.在体系中添加(;RT-g-MAH时,共混物的力学强度也能得到提高,且GRT-g-MAH的加入量为17%时,共混物的力学强度达到最高,表明GRT-g-MAH可用作胶粉/HDPE共混的相容剂.     

废胶粉填充改性RHDPE增容研究

研究了废胶粉的活化处理、不同种类相容剂对回收高密度聚乙烯/废胶粉(RHDPE/WRP)共混体系的增容效果.结果表明,WRP活化处理对提高WRP界面活性有效果.不同相容剂对提升共混体系性能的影响不同,其中添加10份马来酸酐接枝聚乙烯(PE-g-MAH)相容剂对提升RHDPE/活化WRP体系整体性能最有效,可使RHDPE/WRP共混材料的拉伸强度从简单共混物的18.8 MPa提高到22.5 MPa,缺口冲击强度从37.5 kJ/m2提高到60.9 kJ/m2;热变形温度从55.8℃提高到63.6℃.     

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。     

PP/EVA/胶粉热塑性弹性体的制备及性能研究

制备聚丙烯(PP)/乙烯-醋酸乙烯共聚物(EVA)/胶粉热塑性弹性体(TPV),研究胶粉改性剂201酚醛树脂、松香、橡胶活化剂450、橡胶再生剂RV,相容剂聚丙烯接枝马来酸酐(PP-g-MAH)用量,以及EVA/胶粉共混比对TPV性能的影响。结果表明:与采用未改性胶粉相比,采用改性胶粉制得的TPV拉伸强度、拉断伸长率和撕裂强度增大;当PP-g-MAH用量为5份、EVA/胶粉共混比为15/45时,TPV的综合性能较好。     

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...     

胶粉/LLDPE弹性体合金的研制

系统研究了废胶粉（GRT）／线型低密度聚乙烯（LLDPE）弹性体合金（GRT／LLDPE）的配方，以及粒径，GRT含量，相容剂和硫化剂（DCP）用量对共混物力学性能的影响，结果表明，采用两阶共混法，当GRT／LLDPE共混比为：60：40，DCP用量为2份，相容剂马来酸酐三单体接枝物用量为3－5份时，所得弹性体合金力学性能最佳，弹性体合金的拉伸强度从简单共混物的5．8Mpa上升到11．1MPa，撕裂强度从39．4kN/m，上升到63．4kN/m，断裂伸长率从180％增加到260％。     

相容剂PP-g-MAH对PP/PA12形貌及性能影响

采用熔融共混制备了不同相容剂马来酸酐接枝聚丙烯(PP-g-MAH)含量的聚丙烯(PP)/PP-g-MAH/聚酰胺12(PA12)共混体系,通过对体系的平衡扭矩、差式扫描量热法(DSC)、扫描电子显微镜(SEM)及力学性能等测试,分析了共混体系中相容剂PP-g-MAH对PP/PAl2形貌及性能的影响.结果表明,PP-g-MAH能改善PP/PAl2的界面相容性,PA12能更好地分散在PP基体中,最佳相容剂添加质量分数为12%.此时,杨氏模量比未添加相容剂时提高了60.7%,断裂伸长率提高了79.9%,冲击强度提高了345.2%.     

聚丙烯/冷冻胶粉复合材料结构与性能的研究

采用熔融挤出的方法制备聚丙烯（PP）、冷冻胶粉（LGTR）、相容剂及增韧剂的共混物,研究了胶粉用量、相容剂种类和用量及增韧剂对共混体系力学性能和微观结构的影响。结果表明,LGTR的加入会降低PP的力学性能,但随着LGTR用量的增加,共混体系的冲击强度上升;相容剂的使用会增加PP与LGTR的相容性,使力学性能提高;热塑性聚烯烃类弹性体（POE）和三元乙丙胶接枝马来酸酐（EPDM-g-MAH）的使用可以有效提高PP/胶粉共混体系的缺口冲击强度,并且增韧剂的使用可以提高PP与LGTR之间的相容性;高密度聚乙烯（PE-HD）/POE并用做增韧体系时,可以进一步提升共混体系的韧性,提高冲击强度。     

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。