交联聚乙烯管国内外发展概况

介绍了交联聚乙烯(PE-X)及其管材的交联机理和产品特点.比较了过氧化物PE-X管、硅烷PE-X管、辐照PE-X管的生产工艺和产品优缺点.综述了PE-X管国内外近几年的发展、市场需求、生产以及专用料的开发应用情况,针对地暖管领域目前市场使用的PE-X管、耐热聚乙烯管、无规共聚聚丙烯管、聚1-丁烯管进行性能比较,阐述了P...     

新型塑料给水管材的性能和应用

介绍了在国内新型建筑给水管材中占主导地位的铝塑复合管、交联聚乙烯(PE-X)管、三型无规共聚聚丙烯(PP-R)管的发展,生产工艺和性能特点等.提出了目前新型建筑给水管材市场及推广应用中存在的问题及建议.     

电子加速器在轮胎制造中的应用

采用电子加速器(电子辐照)技术,对轮胎进行预硫化可以减少轮胎的重量。文中详细阐述了电子加速器的工作原理及胶片在辐照下的交联过程。实验证明,辐照后的轮胎耐久性能及强度达到设计标准。     

电子束辐照技术在聚乙烯材料加工改性中的应用

综述了电子束辐照技术用于聚乙烯材料交联和接枝改性的研究情况。通过交联可提高聚乙烯的耐热性和强度；通过接枝可在聚乙烯分子链上引入极性基团，提高表面张力，改进粘合性能等。还介绍了各类电子加速器设备，以及影响辐照反应的因素。     

辐照交联聚乙烯管材专用树脂的研制

通过对辐照交联管材基体树脂及助剂体系的配方研究,讨论了敏化剂品种、用量及抗氧剂用量对体系交联度的影响,确定了辐照交联管材专用树脂的最佳配方,即高密度聚乙烯(6366M)和线形低密度聚乙烯(7042)的配比为80/20,敏化剂M-1和抗氧剂的加人量分别为2.5%和2.5%。还考察了辐照剂量对体系力学性能及结晶度的影响。结果表明:随着辐照剂量的增加,拉伸强度、断裂伸长率下降,材料发生交联的同时也发生了降解。随着辐照剂量的增加,结晶度基本没有发生变化,这说明交联只是发生在非晶区或晶区与非晶区的边缘。加工应用实验表明,专用树脂的各项性能达到进口树脂ME2592的水平。     

塑料管材PE、PE-RT、PE-X的快速鉴别

文章根据PE、PE-RT和PE-X管材的特点,通过红外光谱、耐热性能、熔体质量流动速率(MFR)、交联度、密度与热分级等研究,建立了可快速鉴别该类管材的分析方法。由于PE-X管材的不溶不熔,PE-RT管材的MFR较大,密度较小,且根据热分级测试得出的不同片晶厚度所占的比例不同,能够快速鉴别出塑料管材PE、PE-RT、PE-X,结果准确性高,且周期短。     

桂橡机厂进军塑机行业

桂林橡胶机械厂近年来准确把握市场经济脉搏，最近又成功地介入了塑料机械行业，开发出GXJX-63-PPR管材挤出生产线等塑料机械新产品。 无规共聚聚丙烯(PP-R)塑料管材同交联聚乙烯(PE-X)管材、铝塑复合管一起形成替代镀锌钢管的三大新型绿色环保管材。三种管材各有特点，其中PP-R管最突出的优点是：管材管件采用相同原料制作，可采用热熔接方法连接，寿命长，卫生性能好以及耐高温性能强，近几年在欧州发达国家得到迅速发展。 PP-R管市场前景好，国内企业急于购买RP-R管材生产设备，但进口的价格十分昂贵，此时桂林橡胶机械厂成功开…     

红外线辐照过氧化物交联HDPE管材新技术

红外线辐照过氧化物交联技术是一种新型的结合过氧化物交联和红外线辐照理论的技术，把它应用于交联高密度聚乙烯（HDPE）管材的生产中可提高生产效率，而且管材整体交联均匀性好，因而值得大力推广。     

硅烷交联管材专用HDPE 2300XM的性能与应用

在高密度聚乙烯(HDPE)装置上工业化开发了硅烷交联聚乙烯(PEXb)管材专用HDPE 2300XM。性能测试与应用研究表明:2300XM具有合理的熔体流动速率与密度,其物理性能、流变性能及PEXb管材性能与进口专用树脂HDPE XL6500相当,满足PEXb管材快速挤出与长期使用要求。由2300XM生产的PEXb管材通过了110℃,8 760 h静液压状态下热稳定性试验;2300XM是国内首个通过10 000 h长期静液压分级试验的冷热水用交联聚乙烯管材基础树脂,其PEXb管材最小要求强度等于10 MPa,表明2300XM为交联PE100级管材基础树脂。     

电子辐照技术在轿车胎生产的研究与应用

研究了电子辐照预硫化胶片的交联原理、电子能量与辐照深度的关系,介绍了加速器的选择以及在子午线轮胎生产中的应用。在线电子辐照系统的使用,能够有效地提升轮胎性能并减少橡胶材料,从而降低生产成本,其经济效益显著。     

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。