混炼条件对HAF填充型粉末SBR混炼性能的影响

采用Brabender转矩流变仪研究高耐磨炭黑 (HAF)填充型粉末SBR [P(SBR/HAF) ]和块状SBR (SBR/HAF)在较宽的混炼条件范围内 (转速 40～ 80r·min- 1 ,循环油温 5 0～ 10 0℃ )于密炼机中混炼的流变特性 ,讨论了混炼条件对胶料混炼流变性能的影响。结果表明 ,在试验的转子转速和循环油温范围内 ,P(SBR/HAF)比SBR/HAF表现出较高的表观剪切粘度 ,其对混炼时间的依赖性为SBR/HAF的 5 0 %～ 70 % ,但两者对转子转速和循环油温的敏感性相近     

HAF填充型粉末SBR的混炼流变性能

研究了高耐磨炭黑 (HAF)和芳烃油用量对HAF填充型粉末SBR[P(SBR/HAF) ]和块状SBR(SBR/HAF)胶料混炼流变性能的影响。试验结果表明 ,P(SBR/HAF)胶料的表观混炼转矩、单元混炼功等对混炼时间、HAF和芳烃油用量的敏感程度均小于SBR/HAF ,为SBR/HAF的 5 0 %～ 70 % ;当HAF用量超过 3 0份 ,P(SBR/HAF)胶料具有较小的混炼能耗 ;P(SBR/HAF)胶料的混炼温升对HAF用量不敏感 ,随芳烃油用量的增大而下降     

橡胶型氯化聚乙烯与氯丁胶共混物的性能研究

研究了橡胶型氯化聚乙烯(CM)与氯丁橡胶(CR)共混物的性能。通过改变硫化体系、CR／CM并用比、填料的品种及用量，考察这些因素对CR／CM硫化胶性能的影响。实验结果表明：与噻二唑类硫化体系相比，硫脲类硫化体系硫化的橡胶具有较大的拉伸强度、撕裂强度和断裂伸长率。在CR／CM并用体系中，随着CM用量的增加，硫化胶的拉伸强度、撕裂强度下降。在HAF、SRF、SiO2、CaCO3种填料中，HAF、SiO2对CR／CM的补强效果最好，最佳用量为20～30份。     

P(SBR/NR/HAF)并用胶的性能

在SBR胶乳／NR胶乳共混的基础上，采用凝聚共沉法制备高耐磨炭黑（HAF）填充型粉末丁苯橡胶／天然橡胶并用胶[P(SBR/NR/HAF)]。研究了SBR／NR并用比、制备工艺等对P（SBR／NR／HAF）并用胶的混沌流变性能和物理机械性能的影响，并与块状SBR／NR／HAF并用胶进行了比较。研究表明，与SBR／NR／HAF相比，P（SBR／NR／HAF）的表观剪切粘度在SBR用量小于50份时对混炼时间的依赖性较低，而在SBR用量大于50份后对混炼时间具有更高的依赖性；P（SBR／NR／HAF)硫化胶 拉伸强度在整个并用范围内对SBR／NR并和比不敏感；采用胶乳预混合的工艺制备的P（SBR／NR／HAF）具有较好的物理机械性能。     

聚苯胺的用量对氯丁橡胶的硫化与力学性能的影响

制备聚苯胺(PAN)/氯丁橡胶(CR)共混胶,研究了PAN的用量对CR/PAN共混胶的影响。结果表明:PAN中的N—H可以促使CR发生交联,随着PAN用量的增加,共混胶的门尼黏度显著增加。在高温下PAN可以充当CR的交联剂,增加PAN的用量可以加快硫化速率,减少硫化时间,提高交联密度。在PAN用量为15份时,共混胶的力学性能最佳。     

半补强炭黑填充型粉末氯丁橡胶(Ⅰ)粒径分布

采用均匀试验设计的方法研究了三个主要因子(炭黑、炭黑分散剂、包覆剂)对半补强炭黑(SRF，N765)填充型硫调节型粉末氯丁橡胶[P(CR／SRF)]产物粒径分布和产物的接触污染性的影响，建立了这些性能与上述变量之间的函数关系模型，并进行了验证。研究表明，增加炭黑用量和炭黑分散剂用量有利于减小产物粒子的平均粒径；而产物的接触污染性随炭黑分散剂用量和包覆剂用量的增加而降低。验证结果表明，所提出的模型可以很好地表征产物特性与三个变量之间的关系。SEM分析表明，P(CR／SRF)粒子表面和内部尚存在部分未被包覆的游离炭黑粒子是造成接触污染性的主要原因。     

TPU/EVA共混物混炼工艺的研究

采用转矩硫化仪考察填料种类和用量、混炼初始温度、混炼时间和转子转速对热塑性聚氨酯（TPU）/乙烯-乙酸乙烯酯共聚物（EVA）共混物性能的影响。结果表明,与炭黑填充TPU/EVA共混物相比,白炭黑填充胶料的混炼效果和拉伸性能较好,白炭黑最佳用量为30份;TPU/EVA共混物的优化混炼条件为：混炼初始温度160℃,混炼时间10～15min,转子转速45r·min^-1。     

半补强炭黑填充型粉末氯丁橡胶(Ⅱ)物理机械性能

采用均匀试验设计的方法研究了三个主要因子(炭黑、炭黑分散剂、包覆剂)对半补强炭黑(SRF)填充型硫调节型粉末氯丁橡胶[P(CR／SRF)]混炼胶的硫化特性、硫化胶老化前与老化后物理机械性能的影响。建立了这些性能与上述变量之间的函数关系模型，并进行了验证。验证结果表明，本章所提出的模型可以很好地表征产物性能与三个变量之间的关系。扫描电镜(SEM)分析表明，炭黑在P(CR／SRF)中的分散程度优于CR／SRF，采用粉末化技术有利于提高填料在橡胶基体中的分散效果。     

CR混炼过程中焦烧性能的研究

测试了CR在较宽混炼温度 ( 110～ 160℃ )和转子转速 ( 4 0～ 10 0r·min- 1 )范围内的混炼焦烧时间ts 和动态硫化指数Δt以及相应温度范围的门尼焦烧性能 (t5和Δt30 ) ,指出门尼焦烧性能不能真正反映混炼胶在实际加工过程中的焦烧特性。根据试验数据 ,拟合了CR的混炼焦烧性能与混炼温度或转子转速的关系及关系模型 ,从橡胶力化学反应的角度解释了温度和转子转速对CR混炼焦烧性能的影响趋势 ,并在此基础上对该模型进行了验证。方差、回归分析结果表明 ,该模型可以很好地表征CR混炼焦烧性能与混炼温度和转子转速之间的关系 ,在试验范围内 ,转子转速对CR混炼焦烧性能的影响比温度大 ,且两者间存在一定的交互作用。     

短纤维-橡胶复合材料的混炼工艺

研究了转子转速和短纤维用量对短纤维-橡胶复合材料混炼过程及硫化胶质量的影响。结果表明,随着转子转速和短纤维用量的增加,混炼过程中消耗的最大功率、单位能耗等增加,当转子转速为70r/min,聚酯短纤维用量为3份时,硫化胶的拉伸强度、撕裂强度等物理机械性能出现最佳值。     

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。