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)。     

镍基涂膜电化学法制备聚苯胺/聚乙烯醇复合膜

报道了-种在镍基板上涂覆聚乙烯醇(PVA)膜,通过电化学法制备聚苯胺/聚乙烯醇(PANI/PVA)复合膜的方法,再将该复合膜剥离后覆于IT0导电塑料上,考察了其电致变色性.通过循环伏安和交流阻抗测试,确定了电化学法制备PANI/PVA复合膜的工艺条件.实验结果表明:当nssA/nH2so4=1∶1,激发电压为1.10～...     

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。     

聚苯胺-乙烯三叔丁基过氧硅烷复合膜的制备及其电致变色性能的研究

采用恒电位法在氧化铟导电玻璃上电聚合制备了聚苯胺(PAn),利用溶液复合法合成了掺杂态聚苯胺-乙烯三叔丁基过氧硅烷复合电致变色膜,并对其结构和电致变色性能研究。结果表明,复合电致变色膜在稳定态时仅出现第二氧化峰,在外加电压下其颜色在绿色至紫色之间可逆变化,聚合物中加入偶联剂,可提高电致变色膜与导电玻璃基底的粘结性及改善复合膜的耐溶剂性能。     

聚苯胺微乳液合成及其电致变色性

用 (NH4) 2 S2 O8为氧化剂 ,在功能质子酸 水 正丁醇三元体系中 ,用微乳液法合成了聚苯胺。以聚苯胺的电导率和电致变色性能为标准 ,讨论了引发剂、DBSA、反应温度和反应时间对聚苯胺性能的影响 ,并对影响聚苯胺 /聚乙烯醇复合膜的性能因素作了初步探讨。结果表明 :与用常规乳液法合成的聚苯胺相比 ,用微乳液法合成的聚苯胺与聚乙烯醇所成的膜 ,其电导率提高了 2个数量级 ,电致变色性能也更好。     

不同酸掺杂聚苯胺的性能研究

合成了盐酸(HC1)、氨基磺酸(NH2SO3H)、十二烷基苯磺酸(DBSA)掺杂的聚苯胺(PANI),探讨了酸用量、氧化剂用量、反应时间以及反应温度等因素对产物电导率的影响,并对这3种酸掺杂的聚苯胺的压片电阻和热稳定性进行了比较.结果表明:当c(HCl)=0.5 mol·L-1,反应时间为6 h,n(APS)∶n(An)为1.0,在1 ℃左右下所得HCl掺杂的PANI的电导率为1.98 S·cm-1;当c(NH2SO3H)=1.0 mol·L-1,反应时间为6 h,n(APS)∶n(An)为2.0,在2 ℃左右下所得NH2SO3H掺杂的PANI的电导率为0.26 S·cm-1;当c(DBSA)=1.0 mol·L-1,反应时间为8 h,n(APS)∶n(An)为2.0,在2 ℃左右下所得DBSA掺杂的PANI的电导率为0.98 S·cm-1.对于产物的固体压片电阻,HC1掺杂PANI最小为10 Ω,NH2SO3H掺杂PANI最大为120 Ω.而对于产物的热稳定性,NH2SO3H和DBSA掺杂的PANI具有较好的环境稳定性,要好于HC1掺杂的PANI.     

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。     

PVA/ P（AA-Co-AN）/ PVA渗透汽化膜的研究

制备一种PVA/P(AA-Co-AN)/PVA复合膜用于甲醇水溶液的分离,膜的主体部分P(AA-Co-AN)由添加纳米S iO2粉末的丙烯酸(AA)和丙烯腈(AN)通过溶液共聚制得,两侧为交联聚乙烯醇(PVA)。考察了复合膜在高质量分数甲醇水溶液中的溶胀性能,探讨了浸泡液温度及浸泡液质量分数对溶胀度的影响,测试了复合膜的力学性能。考察了不同单体配比〔n(AA)∶n(AN)〕所制备的复合膜在不同质量分数甲醇水溶液,不同温度下的渗透汽化性能。结果显示,复合膜在高质量分数甲醇水溶液中具有良好的溶胀性能及渗透汽化性能;在n(AA)∶n(AN)=1∶1下所制备的复合膜,对高质量分数甲醇水溶液分离效果最佳,60℃时分离w(甲醇)=98%的水溶液,分离因子可达1 534,通量为583 g/(m2.h)。     

纳米ZnO/纤维素纳米晶/聚乙烯醇复合膜的制备及性能

采用球磨法制备的纤维素纳米晶(CNC)及市售纳米ZnO对聚乙烯醇(PVA)进行改性,改善了PVA膜的力学性能,并且,赋予其抗菌性,测试复合膜的力学性能、水蒸气透过性能及抗菌性能。结果表明,加入CNC后,提高了PVA膜的力学性能和阻湿性能,加入纳米ZnO后,复合膜对金黄色葡萄球菌具有一定的抗菌性能,并且,能进一步提高复合膜的拉伸强度,但是,降低了复合膜的阻湿性能。当CNC的添加量为3%、纳米ZnO∶CNC=2∶1(摩尔比)时,复合膜综合性能较好,拉伸强度为73.7 MPa,与纯PVA膜相比,提高了77.2%;断裂伸长率为3.8%,与纯PVA膜相比,提高了46.1%;水蒸气透过系数为3.44×10^-13 g·cm/(cm²·s·Pa),与纯PVA膜相比,提高了11.7%。     

基于溶胶凝胶法制备WO3电致变色膜的溶胶特性研究

WO3是用于电致变色玻璃的阴极电致变色材料之一,采用溶胶凝胶法制备WO3薄膜具有设备简单、成本低、适合大面积制膜等特点,WO3溶胶的稳定性是一个值得深入研究的课题.采用过氧化聚钨酸法制备WO3溶胶,主要考察了钨粉-H2O2反应温度、过氧聚钨酸-乙醇反应温度、钨粉和H2O2配比等因素对溶胶稳定性的影响.研究结果表明:钨粉和H2O2反应在冰水浴中进行时控制温度在8℃以下可避免白色沉淀物过多产生.当钨粉与H2O2摩尔比为1∶7,过氧聚钨酸-乙醇反应温度为45～ 50℃,并再在80℃浓缩后可以得到稳定性和成膜性好的透明的橘黄色溶胶.     

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。