粉状NBR与PVC的共混

PVC与粉状NBR(丁腈橡胶)共混可改善其工作特性和加工性能,共混物可与热塑弹体相媲美。     

N型树脂增韧剂产品介绍

一、前言 N型树脂增韧剂其主要成份是羧基丁腈橡胶粉,它是在乳状丁腈橡胶胶粒的外球面上接枝含羧基不饱和烃而悬浮成粉状羧基丁腈橡胶。其结构特征是羧基不饱和烃联结在丁腈橡胶的侧链呈核壳结构,核是弹性体的丁腈橡胶、壳是塑性的羧基不饱和烃聚合物、其接枝后的胶团呈蜂窝状,光波可在胶团内通过,可制聚氯乙烯橡塑合金的透明制品。由于其外壳含极性羧基,因此与聚氯乙烯     

聚氯乙烯(PVC)改性剂──乳液丁腈/聚氯乙烯(NBR/PVC)共沉粉末丁腈胶

丁腈橡胶是PVC的优良改性剂，可提高PVC制品的抗冲性能、耐寒性，改善成型加工性能，它与PVC树脂有十分良好的相容性，在树脂中不挥发、不迁移，起长期内增塑作用。可是普通丁腈橡胶均为25kg重的整块胶，这样大块的胶很难与粉状PVC树脂混合，从而使它的应用受到了很大的限制。北京化工学院采用了腈乳胶与PVC粉共沉法制得了粉状NBR／PVC共沉粉末丁腈。可广泛应用于各种PVC硬制品和软制品的改性，如PVC密封胶条（包括汽车密封条和门窗密封条）、优质PVC鞋料、电缆、纺织胶辊、塑料冷弯管及硬质PVC塑料门窗等各种制品，可代替进…     

丁腈橡胶臭氧化制备羧基丁腈橡胶

以臭氧氧化丁腈橡胶合成了羧基丁腈橡胶,研究了反应时间、反应温度、臭氧通入量及丁腈橡胶胶液质量浓度对产物特性黏数和酸值的影响.结果表明,以丁腈橡胶臭氧化制备羧基丁腈橡胶,在实验范围内,反应温度升高、增大臭氧通入量和降低丁腈橡胶胶液质量浓度可以提高羧基丁腈橡胶的羧基含量,降低丁腈橡胶的相对分子质量.但是反应时间的影响较为复...     

凹凸土/丁腈橡胶纳米复合材料的制备与性能

以丁腈橡胶为基体材料，纳米级凹凸土为添加剂，对混炼工艺条件及纳米级凹凸土对丁腈橡胶性能的影响进行了研究。试验结果表明，纳米级凹凸土可以大大提高丁腈橡胶的性能，纳米级凹凸土不只作为增量填充剂，在混炼过程中，必须充分加工以保证其在胶料中均匀分布，以提高纳米凹凸土与丁腈橡胶的相容性，同时，探讨了纳米粒子改性丁腈橡胶性能的机理。     

新型热塑性弹性体的开发应用

新型热塑性弹性体的开发应用据《制品特品信息》，１９９５，№３：９报道，汕头经济特区澄海永新汽车橡塑配件总厂采用聚氯乙烯和粉末丁腈橡胶等材料，开发了热塑性弹性体应用于汽车工业等领域，并形成了生产能力。该材料的配方如下：粉状ＰＶＣ１００；粉末ＮＢＲ２０；...     

硫化氢腐蚀丁腈橡胶的机理

探讨了硫化氢气体及其饱和水溶液对丁腈橡胶性能的影响,采用吉布斯函数验证了硫化氢对丁腈橡胶中残留氧化锌腐蚀的可能性,并通过红外光谱定性和定量分析了硫化氢对丁腈橡胶大分子的腐蚀行为。结果表明,硫化氢的腐蚀会降低丁腈橡胶的物理机械性能;硫化氢气体并不能腐蚀丁腈橡胶中的氧化锌,只有在发生水解后反应才能自发进行;硫化氢气体及其饱和水溶液均能与丁腈橡胶主链中的碳碳双键及侧基氰基发生反应,在硫化氢气体中以双键腐蚀为主,在硫化氢饱和水溶液中则以氰基腐蚀为主,其中腐蚀氰基时为一次加成和二次加成反应。     

丁腈橡胶与聚氯乙烯共混胶耐油性能的研究

(一)前言 橡胶与合成树脂共混是改善高分子材料性能的一个重要途径。丁腈橡胶(NBR)是目前应用最广泛的耐油橡胶,具有优越的耐油性能。为进一步开发丁腈橡胶的应用,本工作以丁腈橡胶(NBR)与聚氯乙烯(PVC)共混,提高了丁腈橡胶在高温下的耐油性能。     

氢化丁腈橡胶的特殊品种及应用

为进一步提高氢化丁腈橡胶的性能,原材料开发商研制生产了包括低温氢化丁腈橡胶、耐热氢化丁腈橡胶、易加工氢化丁腈橡胶、丙烯酸盐增强氢化丁腈橡胶、氢化羧基丁腈橡胶和氢化丁腈橡胶/塑料共混胶等一系列特殊品种。     

羧基丁腈橡胶改性酚醛树脂的研究

以羧基丁腈橡胶和苯酚为原料,通过F-C烷基化反应,再与甲醛聚合制得羧基丁腈橡胶改性的酚醛树脂,并对工艺进行优化.结果表明,最优工艺条件为:甲醛和苯酚的摩尔比(F/P)为0.80,羧基丁腈橡胶用量为苯酚用量的2.5％,以氢氟酸为催化剂,催化剂用量为苯酚用量的0.30％,F-C烷基化反应温度为120℃,反应时间为6 h.所...     

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。