永久抗静电PA6/ABS材料的制备

采用双螺杆挤出的方法将永久型抗静电母粒与尼龙(PA)6、(丙烯腈/丁二烯/苯乙烯)共聚物(ABS)熔融共混,制得永久型抗静电PA6/ABS材料.研究表明,适量马来酸酐接枝ABS的加入,可以显著提高ABS和PA6的相容性;随着永久型抗静电母粒用量的增加,PA6/ABS合金材料的表面电阻率明显下降,20%～30%的抗静电母粒可使PA6/ABS材料的表面电阻率达到1×107～1×108Ω,一年之后仍保持为1×108Ω,具有永久抗静电性能;抗静电PA6/ABS材料具有优异的可染色性.     

新型抗静电ABS树脂的制备及性能

丙烯腈-丁二烯-苯乙烯(ABS)树脂因其具有高绝缘性,在使用过程中表面容易积累大量的静电荷,引发安全事故,所以有必要对其进行抗静电改性。高分子永久型抗静电剂因其可以在基体树脂内部呈三维网络状分布,形成导电网络来消散静电荷,而被广泛用于基体树脂的抗静电改性。本文通过将高分子永久型抗静电剂ABS-2MP和JL-AS-55与ABS接枝共聚物、苯乙烯-丙烯腈(SAN)树脂共混制备了抗静电ABS树脂。研究了不同配比的抗静电剂ABS-2MP和JL-AS-55对抗静电ABS树脂性能的影响。结果表明：添加抗静电剂ABS-2MP和JL-AS-55的ABS树脂的表面电阻率可从10¹⁴～10¹⁶Ω降低到10⁹～10¹⁰Ω,并且具有良好的耐水洗性能和亲水性能。同时,加入抗静电剂ABS-2MP和JL-AS-55后,ABS树脂的熔体质量流动速率能够增大到18.0 g/10min,缺口冲击强度和拉伸强度也能达到21.4 kJ/m²和27.6 MPa。当ABS-2MP∶JL-AS-55=1∶3(质量比)时,A...     

不同抗静电剂对聚丙烯抗静电性能和力学性能的影响

通过熔融共混法制备不同配比的多元醇脂肪类抗静电剂、磺酸类抗静电剂改性聚丙烯（PP）抗静电材料;分别考察了两种抗静电材料的体积电阻率、表面电阻率、拉伸强度、冲击强度和表面硬度。结果表明：两种抗静电剂的加入都能够降低PP的表面电阻率,起到抗静电效果,而多元醇脂肪类抗静电剂的效果要比磺酸类抗静电剂突出;两种抗静电剂对PP体积电阻率影响都不大。此外,两种抗静电剂的加入会降低PP的拉伸强度和表面硬度,对冲击强度影响不大。在PP中添加6份多元醇脂肪类抗静电剂,抗静电效果最佳,其表面电阻率为4.7×1011Ω,拉伸强度为27.28MPa,冲击强度为4.9kJ/m2,邵氏硬度为64.8。     

DMDAAC–HEA共聚物对ABS的抗静电作用

以无水乙醇为溶剂,偶氮二异丁腈为引发剂,合成二甲基二烯丙基氯化铵(DMDAAC)–丙烯酸羟乙酯(HEA)共聚物,分析了共聚物中单体DMDAAC与HEA质量比对其抗静电性能的影响,发现DMDAAC与HEA质量比为2∶1和1.5∶1时,共聚物的抗静电效果较理想。将DMDAAC与HEA质量比为2∶1的共聚物作为抗静电剂添加到丙烯腈–丁二烯–苯乙烯塑料(ABS)中制备抗静电ABS,研究了抗静电剂添加量、储存时间、环境相对湿度、水洗次数等对ABS抗静电性能的影响,并研究了抗静电剂对ABS力学性能的影响。结果表明,随抗静电剂添加量的增加,抗静电ABS的表面电阻率(ρs)和体积电阻率(ρv)迅速下降,当抗静电剂质量分数为1%时,抗静电ABS的ρs下降至1×108Ω左右,此后基本保持稳定;在此添加量下,抗静电ABS的ρs和ρv随储存时间的增加而迅速下降,在20 d左右达到稳定值,其在低相对湿度环境下的ρs仍低于1×1010Ω,水洗200次后仍具有一定的抗静电效果,且力学性能下降幅度较小。     

ABS/改性PVA永久抗静电复合材料的结构和性能研究

对聚乙烯醇(PVA)增塑改性大大降低其结晶度,使其熔点降低,在较低温度(180℃)实现熔融加工.将改性PVA和ABS共混改性可制备出永久抗静电ABS/PVA合金.复合材料随PVA用量的增加力学强度现增加后减小,表面电阻率逐渐降低.当PVA的质量份数在30％时,复合材料的表面电阻率降到109Ω以下实现永久抗静电并有较好的...     

抗静电热致液晶高分子的制备与性能研究

将碳纤维与热致液晶高分子(TLCP)经成型加工制得样条,24 h后测试样条的表面电阻率、熔点、结晶度,并考察碳纤维的加入对液晶高分子力学性能的影响。结果表明:TLCP表面电阻率随碳纤维含量的增加而下降,当碳纤维含量达到20%时,材料的表面电阻率最低,抗静电效果最佳;碳纤维的加入使结晶度稍有提高,拉伸强度提高明显,但是TLCP的冲击强度有所降低。     

永久抗静电PC/ASA材料的制备

将永久型抗静电母粒与聚碳酸酯(PC)、丙烯腈-苯乙烯-丙烯酸共聚物(ASA)通过双螺杆熔融共混挤出,制备了永久型抗静电PC/ASA材料,进一步考察了永久抗静电剂的用量对永久抗静电型PC/ASA合金的力学性能和抗静电性能的影响,以及永久抗静电剂对PC/ASA合金耐久性和耐水洗性的影响.研究表明:随着永久抗静电剂用量的增加,PC/ASA合金的表面电阻率明显下降,添加11%～19%的抗静电剂可使PC/ASA材料的表面电阻率达到108～1010Ω,而且24个月之后仍保持在同一数量级,具有永久抗静电性能;随着永久抗静电剂用量的增加,PC/ASA合金材料的力学性能稍有下降;添加了永久抗静电剂的PC/ASA合金在水洗100次后,其表面电阻率变化很小.     

抗静电半硬质聚氨酯整皮泡沫的研制

采用导电炭黑及十六烷基三甲基溴化铵作为复合抗静电剂 ,制备了抗静电半硬质聚氨酯整皮泡沫 ,研究了导电炭黑及十六烷基三甲基溴化铵在树脂基体中的添加工艺、用量及材料贮存时间对泡沫体积电阻率及表面电阻率的影响。结果表明 :采用球磨机球磨的方式可以将导电炭黑均匀地分散在聚醚组分中 ;在半硬质聚氨酯整皮泡沫的树脂基体中加入复合抗静电剂 ,所制得泡沫的体积电阻率下降为 10 7Ω·m ,表面电阻率下降为 10 10 Ω ,且所制得的泡沫在贮存 2 5a以后仍具有较好的抗静电性能。     

离子液体-碳纳米管复合材料用于聚氨酯抗静电剂的研究

为降低聚氨酯薄膜的表面电阻率,提高其抗静电稳定性。以离子液体(IL) 1-羟乙基-3-甲基咪唑双三氟甲基磺酰亚胺盐([C2OHmim][Tf2N])和多壁碳纳米管(MCNT)为原料,通过物理改性制备不同配比的离子液体-碳纳米管复合材料,并用其改善聚氨酯薄膜的抗静电性能,最终通过溶液涂膜法制得IL-MCNT/PU薄膜。IR、FT-IR分析结果表明,与IL复合后的碳纳米管具有良好的分散性; IL也通过羟基成功固定在聚氨酯基体中。改性后PU膜的表面电阻率降低了6个数量级,当添加ILMCNT-5时,材料的电阻率由2.1×1013Ω降至2.7×107Ω,经过10 min超声处理后几乎保持不变。与单一组分离子液体相比,IL-MCNT显示出更好的抗静电稳定性;碳纳米管的加入提高了材料的力学性能。     

永久抗静电剂在电子包装用聚丙烯片材材料的应用

采用永久抗静电剂、相容剂及其他助剂改性聚丙烯(PP),熔融共混挤出造粒制备电子包装用永久抗静电PP片材材料。通过正交试验优化了各组分之间的配比,考察了永久抗静电剂、相容剂对PP片材材料力学性能及表面电阻率的影响。结果表明永久抗静电剂用量对复合材料的性能影响最优显著,当永久抗静电剂用量从10份增加到25份,材料的冲击强度增大,最高达18.13 kJ/m2,拉伸强度减小,表面电阻率减小,最小达2.2×109Ω。综合考虑,满足表面电阻率小,拉伸强度大,冲击强度大的聚丙烯用量为75质量份,永久抗静电剂用量为20质量份,相容剂用量为6质量份,其他助剂3质量份。     

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。