共查询到20条相似文献,搜索用时 78 毫秒
1.
以高分子树脂膜为包覆剂,采用凝聚共沉法制备非填充型粉末NBR和超细碳酸钙填充粉末NBR。研究了包覆剂及超细碳酸钙的用量对产物粒径及其硫化胶力学性能的影响。结果表明,当包覆剂用量为10份时,粒径≤09mm的产物占998%,加入超细碳酸钙后可进一步减小产物的粒径;极性适宜的包覆剂及超细碳酸钙对粉末NBR硫化胶有显著的补强作用,故非填充型粉末NBR及超细碳酸钙填充粉末NBR均有良好的力学性能。扫描电镜分析表明,极性适宜的包覆剂与NBR有一定的相容性,并以粒径约05μm的微粒均匀分布于NBR基体中;超细碳酸钙则以原生粒子和粒径≤05μm的团粒存在,它在粉末NBR中的分散性比块状NBR/超细碳酸钙混炼体系有显著改善 相似文献
2.
3.
4.
试验研究包覆剂和超细碳酸钙对粉末丁苯橡胶(PSBR)粒径分布和PSBR/PVC共混物性能的影响。结果表明,以自制的Coron树脂[苯乙烯-马来酸酐(MA)共聚物,简称SMA]作包覆剂时,PSBR的粒径较小,PSBR/PVC共混物的拉伸强度和缺口冲击强度较大;当超细碳酸钙/丁苯胶乳质量比为3.5/6.5时,包覆剂SMA的适宜用量为0.8份,MA/苯乙烯的适宜质量比为0.56/0.24;当包覆剂SMA用量为0.5份时,加分散剂CH1-A的超细碳酸钙填充的PSBR粒径较小,对PVC的改性效果较好,超细碳酸钙的适宜用量为3.5~4份。 相似文献
5.
超细碳酸钙超充粉末丁苯橡胶的制备 总被引:2,自引:0,他引:2
将高分子电解质包覆剂和超细碳酸钙加入丁苯胶乳中,通过共凝聚法制得粉末丁苯橡胶(PSBR)。实验结果表明,PSBR粒径不大于0.9mm,具有良好的力学性能。PSBR的粒径主要由包覆剂的用量决定,超细碳酸钙对橡胶粒子有隔离作用。 相似文献
6.
7.
首先,我们通过比较SBR炭黑和SBR白炭黑硫化胶的各种物理性能,研究了SBR炭黑硫化胶的滚动阻力[tgδ(50℃,15Hz)]和耐湿滑性[tgδ(0℃,15Hz)]的实验室指标是否也适用于SBR白炭黑硫化胶。SBR白炭黑硫化胶的移动因子(logaT)、tgδ值(0℃,15Hz)以及摩擦系数μ值对温度的依赖关系几乎与SBR炭黑硫化胶的相同。因此,我们决定将这些指标用作SBR白炭黑硫化胶性能实验室试验的量度。接着,我们研究了SBR的微观结构及其改性方法对SBR白炭黑硫化胶的这些指标和蓝朋(Lambourn)磨耗性能的影响。苯乙烯含量及玻璃化温度(Tg)对tgδ(50℃,15Hz)和蓝朋磨耗性能有影响。分批聚合溶液丁苯橡胶(S-SBR)的tgδ(50℃,15Hz)比乳液丁苯橡胶(E-SBR)和连续聚合S-SBR低。Tg对0℃,15Hz时的tgδ具有显著影响。在SBR白炭黑硫化胶中未观察到改性方法对物理性能的影响。这是SBR白炭黑硫化胶和SBR炭黑硫化胶的主要差别。通过S(动态应变振幅),G′(动态贮存模量)和tgδ(150℃)可以解释SBR白炭黑硫化胶的滚动阻力为何较低。 相似文献
8.
9.
10.
高岭土填充型粉末丁苯橡胶的制备与性能的研究 总被引:2,自引:0,他引:2
以SBR胶乳为原料,经表面改性的高岭土(MO)为填料,高分子树脂为包覆剂,以凝聚共沉法研制高岭土填充型粉末SBR[P(SBR/MO)]。研究了影响产物粒径及硫化胶力学性能的因素,并与块状SBR/MO1机械混炼胶料硫化胶的力学性能进行比较。结果表明:当高岭土用量≥100质量份、包覆剂用量≥5质量份时,可获得粒径≤0.9mm的P(SBR/MO1)达100%;当高岭土的用量为100质量份及其表面改性剂用量的4质量份、Tg为18℃的包覆剂的用量为5质量份时,所获得的P(SBR/MO1)硫化胶力学性能最好。 相似文献
11.
12.
M. S. J. Simmonds W. M. Blaney F. Delle Monache M. Marquina Mac-Quhae G. B. Marini Bettolo 《Journal of chemical ecology》1985,11(12):1593-1599
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. 相似文献
13.
14.
15.
16.
Cheng-Le Zhao Shane Porzio Alan Smith Haiyan Ge H. T. Davis L. E. Scriven 《Journal of Coatings Technology and Research》2006,3(2):109-115
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. 相似文献
17.
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. 相似文献
18.
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. 相似文献
19.
中蓝晨光化工研究院有限公司《塑料工业》编辑部 《塑料工业》2009,37(3)
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. 相似文献
20.
中蓝晨光化工研究院《塑料工业》编辑部 《塑料工业》2007,35(3):1-25,67
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。 相似文献