不同质子酸掺杂对聚苯胺合成与性能的影响

由化学氧化法制得的聚苯胺(PANI)被不同质子酸掺杂。研究盐酸(HCl)、硫酸(H2SO4)、樟脑磺酸(CSA)和十二烷基苯磺酸(DBSA)掺杂对PANI产率、溶解性以及电导率的影响。研究发现,HCl掺杂的PANI电导率为0.263 4 S/cm、产率可达到78.83%。还讨论不同HCl浓度和不同过硫酸铵/苯胺(APS/An)的物质的量比对HCl掺杂PANI产率和电导率的影响,当HCl的浓度达到1.2 mol/L、APS/An物质的量比为0.6时,PANI的电导率和产率均为最大值。     

聚苯胺/nano-ATO导电复合材料的原位聚合与表征

用原位聚合法,以十二烷基苯磺酸(DBSA)/HC l混酸为掺杂剂,过硫酸胺(APS)为氧化剂,制备了聚苯胺/掺锑二氧化锡(ATO)导电复合材料。探讨了ATO用量对导电复合材料电导率的影响。在n(苯胺)∶n(APS)∶n(DBSA)=1∶1∶0.7,m(ATO)∶m(苯胺)=0.1∶1时,复合材料室温25℃的电导率最高可达8.35 S/cm,比通常方法合成的聚苯胺和nano-ATO的电导率分别提高约1至2个数量级。通过FTIR、XRD、SEM和TEM对目标物进行了表征,结果表明,苯胺优先在ATO纳米粒子表面聚合,形成聚苯胺包覆ATO的导电复合材料。     

不同酸掺杂聚苯胺的电化学聚合及性能

采用循环伏安（CV）法在镀金PET膜上分别聚合了硫酸（H2SO4）、十二烷基苯磺酸（DBSA）、硫酸-十二烷基苯磺酸掺杂的聚苯胺（PANI）膜,对比研究了掺杂酸种类对PANI结构和性能的影响。结果表明,SO42?、DBSA?可以随聚合过程进入PANI分子链;H2SO4掺杂的PANI具有较高的电导率,但是在空气中的稳定性较差;大分子的DBSA使PANI优先产生单螺旋的纤维,提高了PANI在平行分子链方向上的结晶度和在空气中的稳定性;相对于单一酸掺杂,复合酸掺杂的PANI在酸溶液中电扫描表现出优良的循环伏安特性,在保持较高电导率的同时,提高了PANI在空气中的稳定性。     

聚苯胺/钨硅酸复合材料气敏性能研究

以钨硅酸(H4SiW12O40)为掺杂剂,过硫酸铵(APS)为氧化剂,制得PANI/H4SiW12O40复合物。该复合物是以H4SiW12O40为核,以PANI为表层的新型聚合物,检测表明在室温下对氨气有较好的灵敏度。通过控制变量法,考察了不同制备因素对PANI/H4SiW12O40乳液稳定性及其复合材料气敏性能的影响,初步确定试验中各反应物的用量范围和实验条件:n(DBSA)/n(An)=2.0,n(APS)/n(An)=1.0,m(H4SiW12O40)/m(An)=3.0,聚合时间为16 h。     

PANI/PAVC复合材料气敏性能的研究

以聚乙酸乙烯酯(PVAC)为掺杂剂,过硫酸铵(APS)为氧化剂,十二烷基苯磺酸(DBSA)为乳化剂,制备出稳定的聚苯胺/聚乙酸乙烯酯(PANI/PVAC)乳液状态的复合材料。经检测表明该复合材料稳定性好,在室温下对氨气有很好的灵敏度。利用单因素变量法系统考察了不同因素对乳化液稳定性及复合材料气敏性能的影响,并优化出最佳工艺条件:n(DBSA)∶n(An)=1.0;n(APS)∶n(An)=1.0;n(VAC)∶n(An)=1.0;聚合时间6 h;反应温度20℃,对含量1×10-3氨气的响应时间为300 s,恢复时间为240 s,灵敏度为56.082,适宜作为室温下的氨气敏感材料。利用红外光谱对该复合材料进行了结构表征。     

乳液聚合法制备聚苯胺/聚乙烯醇电致变色材料

以十二烷基苯磺酸(DBSA)为掺杂剂,在非有机溶剂的两相体系中以聚乙烯醇(PVA)为成膜助剂,采用现场乳液聚合法合成了可直接用于制备电致变色膜的聚苯胺(PAn)/PVA乳液。研究了PVA含量、苯胺(An)与DBSA的量比、氧化剂过硫酸铵(APS)与An的量比及反应温度对膜的电致变色性、导电性的影响。实验结果表明:在w(PVA)=4 3%、n(An)∶n(DBSA)∶n(APS)=0 86∶1∶0 86、反应温度为8℃时,所制得的PAn/PVA乳液可直接制成具有良好电致变色性的自支撑膜(电致变色响应时间小于0 5s,电导率可达2 69×10-4S/m)。     

聚苯胺的制备及其导电性能

以苯胺为单体,过硫酸铵为氧化剂,盐酸为掺杂酸,采用化学氧化法制备出盐酸掺杂聚苯胺(PANI-HA),研究了过硫酸铵与苯胺单体摩尔比(n APS:n An)、HCl浓度、反应温度和反应时间对PANI-HA电导率的影响;采用正交分析法研究了各影响因素对PANI-HA电导率的主次关系。结果表明:影响PANI-HA电导率的主次关系为反应温度n APS:n An反应时间HCl浓度;制备PANI-HA的最佳工艺为nAPS:n An=1.0,HCl浓度1.0 mol/L,反应温度10℃,反应时间8 h。     

不同酸掺杂体系的PANI/BaTiO3复合材料的制备及性能研究

采用原位复合法分别制备了盐酸(HCl)和十二烷基苯磺酸(DBSA)掺杂的导电聚苯胺(PANI)/钛酸钡(BaTiO3)[分别记为PANI(HCl)/、PANI(DBSA)/BaTiO3]复合材料,研究了复合材料的结构、形貌、热性能、电导率及介电性能。结果表明,2种复合材料均具有核壳结构,与PANI(HCl)/BaTiO3相比,PANI(DBSA)/BaTiO3具有更好的热稳定性、更高的电导率及介电常数。     

XPS对电导性纳米聚苯胺的性能表征

以微乳液聚合法合成了导电性纳米聚苯胺(PANI),讨论了乳化剂的用量对聚苯胺电导率的影响,并用XPS对其性能进行了表征.结果表明:当十二烷基苯磺酸钠(SDBS)和苯胺(An)的摩尔比在1左右时, PANI的电导率有最大值;SDBS以两种方式存在,即掺杂PANI的SDBS和自由独立于PANI的SDBS;在一定酸性SDBS掺杂的条件下,(-N= NH )/N比率决定PANI的电导率.     

掺杂态聚苯胺的乳液聚合及其与环氧树脂所制涂层的耐蚀性

以十二烷基苯磺酸钠(SDBS)为乳化剂,采用乳液聚合法制备了盐酸或磷酸与十二烷基苯磺酸(DBSA)共掺杂的聚苯胺[(HCl+DBSA)-PANI或(H_3PO_4+DBSA)-PANI]。用扫描电镜、傅里叶变换红外光谱仪、X射线衍射仪和四探针电导率测试仪表征了掺杂聚苯胺的形貌、结构和电导率。将添加了掺杂态聚苯胺的E44环氧树脂刷涂在Q235低碳钢表面得到复合涂层(PANI/EP),并通过电化学阻抗谱和浸泡试验考察了它们在3.5%NaCl溶液中的耐蚀性。两种共掺杂态聚苯胺都呈束状结构,(HCl+DBSA)-PANI的结构更均一。添加PANI可以明显提高环氧涂层对碳钢的防腐作用,其中(HCl+DBSA)-PANI的效果更好。     

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。