HPVC/BR共混体系的性能研究

采用动态硫化方法制备高聚合度聚氯乙烯／顺丁橡胶(HPVC／BR)共混型热塑性弹性体，考察了单一组分增容剂丁腈橡胶(NBR)、氯化聚乙烯(PE—C)和(氢化苯乙烯／丁二烯／苯乙烯)嵌段共聚物(SEBS)，复合增容剂SEBS／NBR和PE—C／NBR及交联程度对HPVC／BR共温体系相容性的影响。结果表明，使用复合增容剂可明显改善HPVC／BR共混物的性能；动态硫化在改善共混物力学性能方面起主要作用。     

反应增容聚丙烯/废胶粉共混物的研究

按一定的次序将单体二乙烯基苯(DVB)、马来酸酐(MAH)、引发剂过氧化二异丙苯(DCP)与聚丙烯(PP)及废胶粉(WRP)等在高速混合机中混合均匀后.在双螺杆挤出机中就地反应增容制备PP/WRP共混材料,讨论了DVB/MAH/DCP的用量对PP/WRP共混物的拉伸强度、缺口冲击强度以及弯曲强度的影响.通过扫描电镜(SEM)分析了反应增容对PP/WRP共混物界面的影响.结果表明,双单体反应增容能有效抑制PP降解,改善共混物界面相容性.提高共混物的力学性能.当引发剂和双单体的质量分数分别为0.2%和3.0%,DVB/MAH的质量比为3～4时,PP/WRP共混物的综合性能最佳.     

聚乙烯-聚丙烯嵌段共聚物的结构、性能与应用

通过核磁共振氢谱,差示扫描量热分析(DSC),广角X射线衍射(WAXD),小角X射线散射(SAXS)以及拉伸与冲击实验,研究了新型增容剂等规聚丙烯-聚乙烯嵌段共聚物(iPP-PE)的结构与性能,探究了iPP-PE嵌段共聚物增容无规共聚聚丙烯(PPR)/聚烯烃弹性体(POE)共混物对其力学性能的影响。结果表明,在iPP-PE中,两组分存在于材料中并且可以独立结晶。充分降温结晶条件下,两组分不发生相分离。从纳米结构的表征上来看,iPP-PE有一个平均的长周期,PP先于PE结晶。使用iPP-PE增容改性PPR与POE共混物,添加少量增容剂(5%),提高POE含量,断裂伸长率增大,增容剂可以改善共混体系的相容性。当样品中POE含量不变(10%),提高样品中增容剂的含量,断裂伸长率呈现上升趋势,共混物相容性更优异。添加增容剂与POE后,样品冲击强度变大,改善了PPR本身的脆性,引入增容剂可以增加POE含量来提高共混物韧性。     

PP–R管材专用料抗低温性能的研究

通过在无规共聚聚丙烯(PP–R)中添加不同的改性剂制备PP–R管材专用料。采用差示扫描量热分析、动态力学分析、扫描电子显微镜等技术,分析了不同改性剂对无规共聚聚丙烯(PP–R)管材专用料抗低温性能的影响规律。结果表明,在–10~0℃低温条件下,与未改性的PP–R材料比较,PP–R/聚烯烃弹性体(POE)/高密度聚乙烯(PE–HD)共混料的低温冲击韧性最理想,其综合力学性能最好,0℃的冲击强度为58.35 k J/m2,–10℃的冲击强度也高达47.06 k J/m2。POE/PE–HD在不降低PP–R管材专用料其它力学性能的基础上,显著地提高了PP–R管材专用料低温冲击韧性。     

改性石油树脂的合成及其增容PVC/PE共混物的研究

通过对石油树脂与顺丁烯二酸酐反应条件的考察，确定了其最佳反应条件。运用顺酐化石油树脂与异辛醇酯化反应制备了改性石油树脂(MPR)，并将其作为聚氯乙烯／聚乙烯(PVC／PE)的增容剂，研究了PVC／MPR／PE共混体系的相容性、加工性及其材料的力学性能。结果表明，MPR是PVC／PE共混物的一种良好增容剂，PVC／MPR／PE质量比为100／8／6时，共混物具有良好的塑化效果和流动性能，优良的综合性能。     

尼龙6改性超高分子量聚乙烯

采用挤出成型工艺制备了尼龙6(PA6)改性超高分子量聚乙烯(PE–UHMW)共混材料。研究了PA6含量对PE–UHMW/PA6共混材料热性能及力学性能的影响。研究表明,PA6质量分数为30%时维卡软化温度达到145.9℃,较纯PE-UHMW提高了14℃,邵氏硬度达到69,较纯PE-UHMW提高了15%;共混材料的缺口冲击强度随PA6质量分数的增加而降低,在PA6含量不变的条件下,添加适量的增容剂能够改善共混材料的缺口冲击强度。同时结合DSC测试共混材料中PE–UHMW的结晶度与对共混材料的微观形貌扫描观察,进行了PE–UHMW与PA6的作用机理分析。     

废旧聚丙烯编织袋回收料改性应用研究

废旧聚丙烯(PP)编织袋回收料分别与回收聚乙烯(PE)、回收橡胶粉、木粉共混,制备了增韧PP材料、热塑性弹性体和木塑复合材料,采用力学性能测试、SEM和DSC分析等手段对其性能和结构进行了表征。结果表明:随着回收聚乙烯(PE)含量的增加,回收PP/PE共混物的拉伸强度和冲击强度迅速提高;回收PP/橡胶粉共混物中加入聚丙烯接枝马来酸酐(PP-g-MAH)能起到增容的效果,随PP-g-MAH含量的增加,共混物的拉伸强度上升,永久变形减小;在回收PP/木粉复合材料中加入PP-g-MAH后,复合材料的冲击强度明显提高。     

GMA和PE-g-MAH协同增容GTR/PE–HD热塑性弹性体

以过氧化二异丙苯为引发剂,甲基丙烯酸缩水甘油脂(GMA)和马来酸酐接枝聚乙烯(PE-g-MAH)组成协同增容体系,通过动态硫化法制备了废旧轮胎胶粉(GTR)/高密度聚乙烯(PE–HD)热塑性弹性体。研究了PE-g-MAH添加量一定时,GMA用量对GTR/PE–HD热塑性弹性体力学性能、结晶性能和微观形貌等方面的影响。结果显示,添加0.5份GMA,10份PE-g-MAH时,制备的GTR/PE–HD热塑性弹性体综合力学性能最佳,其中拉伸强度为12.82 MPa,断裂伸长率为341.61%,撕裂强度为78.08 kN/m。傅立叶变换红外光谱测试结果表明,GMA上的环氧基团与GTR表面的羧基能发生反应生成酯基。扫描电子显微镜微观形貌表征结果表明,改性后试样断面更加不规整,发生了明显的塑性变形,在两相界面处出现"拉丝"现象。差示扫描量热分析结果表明,随GMA用量增加,熔融温度和结晶温度基本不变,熔融焓和结晶度逐渐降低。     

废旧PE/PP共混体系的增容改性研究进展

聚乙烯（PE）和聚丙烯（PP）是目前生产量和消费量较大的两种塑料,且废弃物总量较多。针对废旧PE/PP的合理利用,探究不同的处理方式。由于简单共混容易导致共混物的力学性能下降,因此,对改善废旧PE/PP的相容性进行探究,分析废旧PE/PP共混物再利用的影响因素,概述常用的增容方法,同时介绍共混物增容策略的研究进展,对增容体系的发展方向进行展望,并重点对纳米增容的前景进行探讨。     

增容聚丙烯/聚苯乙烯共混物的相形态

综述了作为增容剂的接枝共聚物与嵌段共聚物,反应增容,其他技术增容以及共混条件对聚丙烯／聚苯乙烯(PP,PS)共混物的相形态研究进展。PP／PS共混物通过增容可以改善共混物相形态和提高界面粘结,这为提高PP／PS共混物的物理与力学性能提供了依据。     

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。