工艺条件对丙烯酸酯-苯胺共聚乳胶涂层防腐性能的影响

在丙烯酸酯乳液中引入苯胺单体,采用原位乳液聚合法制备了丙烯酸酯-苯胺共聚乳液,分析了共聚机理,详细研究了反应温度、反应时间、共聚乳液中乳化剂种类、乳化剂用量、引发剂与苯胺的物质的量比[n(APS)∶n(An)]等条件对共聚乳液性能及乳胶涂层防腐性能的影响。对制备的共聚乳胶涂层进行了电化学阻抗谱(EIS)、塔菲尔曲线(Tafel)、开路电位(OCP)等测试,通过扫描电子显微镜(SEM)和X射线能谱(EDS)对腐蚀表面进行了分析。结果表明:丙烯酸酯-苯胺共聚乳胶涂层可以使金属基材表面形成钝化膜,且当反应温度为10℃,反应时间为5 h,乳化剂十二烷基苯磺酸钠(SDBS)用量占乳液总质量的2%,引发剂与苯胺的物质的量比为1.5∶1时,共聚乳液的性能及其乳胶涂层防腐蚀性能最佳。     

聚苯胺/磷化含氟丙烯酸酯复合乳胶涂层的防腐蚀性能

以十二烷基硫酸钠(SDS)为乳化剂和掺杂剂,采用化学氧化聚合法合成了一种稳定的聚苯胺(PANI)乳液,该乳液与合成的磷化含氟丙烯酸酯(P-FAc)乳液以不同的比例制备复合乳胶涂层。采用傅里叶变换红外光谱仪对合成的PANI和P-FAc进行了结构表征;通过接触角、附着力、极化曲线、开路电位和电化学阻抗谱测试了复合涂层对Q235钢的防腐蚀性能;通过扫描电子显微镜观察了揭掉PANI/P-FAc复合涂层后的Q235钢表面形貌。结果表明:当PANI乳液与P-FAc乳液的质量比为1∶1时,复合涂层的性能最佳,其腐蚀电流密度仅为1.09×10~(-6)A/cm~2,平衡电位为-0.55 V,阻抗为10~(4.3)Ω·cm~2。     

功能单体对无皂苯胺/硅丙共聚乳胶膜防腐蚀性能的影响

以乙烯基三甲氧基硅烷(VTMS)为功能单体对丙烯酸酯乳液进行改性,得到有机硅改性丙烯酸酯乳液──硅丙乳液(SiAc);然后通过无皂乳液聚合法,以过氧化氢为氧化剂,引入苯胺(Ani),合成了无皂苯胺/硅丙(Ani/SiAc)共聚乳液。通过傅里叶变换红外光谱(FT-IR)、透射电子显微镜(TEM)等方法表征了Ani/SiAc共聚乳胶粒子的结构与形貌。借助动电位极化曲线和电化学阻抗谱(EIS)测量,考察了Ani/SiAc共聚乳胶涂层对Q235钢的防腐蚀性能,讨论了甲基丙烯酸(MAA)和VTMS含量对Ani/SiAc共聚乳液的基本性能以及共聚乳胶膜防腐蚀性能的影响。结果表明,以质量分数均为5%的MAA和VTMS制备的共聚乳液性能最佳,其乳胶膜的水接触角达到95.3°,电化学阻抗值达到2.58×10⁸Ω·cm²,腐蚀电流密度仅为3.89×10^-10 A/cm²。     

有机氟硅改性丙烯酸酯共聚乳液

湖北大学的邱俊英等人以氟醇和乙烯基硅烷为原料合成氟硅单体,在十二烷基硫酸钠／辛基苯基聚氧乙烯醚复合乳化剂,过硫酸钾引发剂存在下分别采用间歇乳液聚合法和核壳乳液聚合法将其与甲基丙烯酸甲酯、丙烯酸丁酯进行乳液共聚,制得含氟硅的丙烯酸酯共聚乳液。用TEM观察乳胶粒的形态,测定反应转化率、乳液的稳定性及乳胶膜的耐水性。结果表明,氟硅单体含量为15％时,核壳法制得的乳液的乳胶膜对水的接触角达1100。     

乳化体系对氟硅改性丙烯酸酯乳液性能的影响

采用不同的乳化体系来制备氟硅改性丙烯酸酯乳液,主要探讨了乳化体系对预乳化液稳定性、聚合稳定性、储存稳定性、转化率、粒径大小与分布以及吸水率的影响。结果表明,在所采用的乳化体系中,由聚氧乙烯-4-酚基醚硫酸铵盐(CO436)与1-丙烯基-α-羟基烷基磺酸钠(COPS-1)组成的复合乳液体系,可制得转化率高达98.85%的稳定乳液,乳液粒径呈单分散分布,乳胶膜的吸水率只有4.31%。     

聚苯胺／膨润土／水性叔氟乳液复合防腐涂层的研究

采用水性叔氟乳液为成膜物质,制得聚苯胺/膨润土/水性叔氟乳液复合涂层材料.电化学阻抗谱和塔菲尔曲线测试结果发现:其具有较高的阻抗和腐蚀电位(-0.20 V)以及最低的腐蚀电流密度(10-10.5A/cm2),通过扫描电镜照片也发现复合涂层在低碳钢表面形成致密的膜层,从而具有良好的防腐蚀效果.     

叔碳改性硅丙乳液复合涂层的防腐蚀性能研究

利用叔碳酸乙烯酯和乙烯基三甲氧基硅烷为功能单体,合成叔碳酸乙烯酯-硅烷改性丙烯酸酯(叔硅丙)乳液,并添加纳米Si O2和纳米蒙脱土等无机材料制备复合防腐蚀涂层。通过接触角、吸水率、电化学阻抗谱、极化曲线、盐雾试验等测试研究了乳液种类及无机纳米材料种类对涂层耐水性和防腐蚀性能的影响。结果表明,叔碳酸乙烯酯和乙烯基三甲氧基硅烷的引入可以有效提高涂层的耐水性和防腐蚀性能,无机纳米材料的加入,尤其是蒙脱土的加入可以进一步提高涂层的防腐蚀性能。复合涂层的吸水率仅为0.7%,腐蚀电流密度为2.91×10-9A/cm2,电化学阻抗可达1.9×108Ω,盐雾试验240 h后无腐蚀扩散现象。     

原位聚合法制备石墨烯改性水性环氧-丙烯酸酯乳液及其防腐性能研究

首先采用改进Hummers法制备氧化石墨烯分散液,再用原位聚合法制备石墨烯改性水性环氧-丙烯酸酯复合乳液,并制备其涂层。主要研究了石墨烯改性水性环氧-丙烯酸酯复合乳液的稳定性和复合乳液涂膜的耐腐蚀性。结果表明:石墨烯能够较好地分散在复合乳液中,成膜时能够很好地填充在涂层的细小缝隙中而产生屏障作用,阻碍腐蚀粒子从介质渗透到铁板表面。因此复合乳液的耐腐蚀性较未改性的水性环氧-丙烯酸酯乳液和直接共混乳液的耐腐蚀性明显增强。     

有机氟硅改性丙烯酸酯共聚物乳液的研究

以氟醇(RfCH2CH2OH)和乙烯基硅氧烷(A-151)为原料合成氟硅单体,然后在十二烷基硫酸钠(SDS)/辛基苯基聚氧乙烯醚(OP-10)复合乳化剂,过硫酸钾(KPS)引发剂存在下,分别采用间歇乳液聚合法和核壳乳液聚合法将其与甲基丙烯酸甲酯(MMA)、丙烯酸丁酯(BA)进行乳液共聚,制备含氟硅的丙烯酸酯共聚物乳液.用TEM观察乳胶粒形态,测定了反应的转化率,研究了乳液的稳定性和乳胶膜的耐水性能.结果表明:氟硅单体含量为15%时,核壳法制得乳液的乳胶膜对水的接触角达110°以上.     

有机氟无机纳米二氧化钛复合改性丙烯酸酯乳液的制备及性能研究

采用半连续种子乳液法将自制的表面亲油性接枝改性纳米二氧化钛与含氟单体甲基丙烯酸十三氟辛酯(G06B)等复合改性丙烯酸酯乳液,用红外光谱(FT-IR)、乳胶膜表面形态分析(AFM)、热重(TG)和拉力机等测试手段研究了表面改性无机纳米TiO_2以及有机氟的引入对乳液及乳胶膜性能的影响。结果表明,改性TiO_2的引入显著增强了聚合物乳胶膜的力学性能并进一步优化了乳胶膜的表面疏水性;乳胶膜疏水性随含氟单体用量增加而增大,热稳定性也有一定地提高,当G06B用量为20%、改性TiO_2用量为0.2%时,乳胶膜的综合性能相对最佳。     

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。