铝材涂装用水溶性羟基丙烯酸树脂的合成

本文选择甲基丙烯酸甲酯、甲基丙烯酸羟乙酯、丙烯酸丁酯和丙烯酸等为主要单体,偶氮二异丁腈为引发剂,在醇醚类溶剂中通过自由基溶液聚合方法制备出水溶性羟基丙烯酸树脂。考察了引发剂、羟值、酸值、中和度对树脂性能的影响。应用实验结果表明:羟值为80mg KOH/g,酸值为60 mg KOH/g,中和度90%的树脂具有优良的物理化学性能,特别适合应用在铝材、马口铁等金属基材领域。     

氨基烤漆用羟基丙烯酸树脂的制备及性能

以甲基丙烯酸甲酯(MMA)、丙烯酸丁酯(n-BA)、丙烯酸(AA)、甲基丙烯酸羟乙酯(HEMA)、苯乙烯(St)和4-叔丁基环己丙烯酸酯(TBCH)为聚合单体,巯基乙醇(β-ME)为链转移剂,偶氮二异丁腈(AIBN)为引发剂,醋酸丁酯(BAC)为溶剂,采用溶液聚合法合成了一系列低相对分子质量的羟基丙烯酸树脂。以氨基树脂作为固化剂,研究了丙烯酸树脂的羟值、酸值及玻璃化转变温度对制成的氨基烤漆漆膜的摆杆硬度、光泽、耐水性、耐酸性及耐碱性的影响。结果表明,当树脂的羟值(以KOH计)为147 mg/g,酸值(以KOH计)为21 mg/g,玻璃化转变温度为25°C时,所制漆膜的综合性能最佳。     

高固含量水性丙烯酸树脂的合成及其氨基烤漆的制备

合成了高固含量水性丙烯酸树脂并由其制得水性丙烯酸氨基烤漆,考察了引发剂用量、自制羟基丙烯酸单体用量、酸值以及玻璃化温度对树脂相对分子质量、亲水性以及漆膜性能的影响。结果表明:引发剂用量为3%,自制含羟基丙烯酸单体用量为20%,酸值60 mg KOH/g,玻璃化温度为-15℃时,树脂的亲水性、漆膜综合性能最佳。     

羟基酸封端型水性聚酯及其水性涂料的研制

使用羟基酸类单体对端羧基聚酯预聚物进行封端获得的水溶性聚酯树脂,具有30mg KOH/g~60mg KOH/g的酸值范围与20mg KOH/g~130mg KOH/g的羟值范围,-50℃~60℃的玻璃化温度,3000~13000的数均分子量。该树脂具有良好的水溶性、储存稳定性、抗水解性、耐水性以及优秀的涂膜性能等,适用于涂料、油墨、粘合剂、及化纤纺织等领域。     

一种金属烤漆用核壳羟丙乳液的合成

采用核壳聚合工艺合成了一种烤漆用羟基丙烯酸乳液,考察了核单体与壳单体的质量比、链转移剂及其用量、羟值和酸值对烤漆性能的影响。结果表明,当核壳单体质量比为3∶4,链转移剂(十二烷基硫醇)为单体质量分数的1.0%,以丙烯酸为酸类单体来控制体系的酸值(以KOH计)为14 mg/g,以丙烯酸羟丙酯为羟基单体来控制羟值(以KOH计)为64.5 mg/g时,所得乳液具有良好的机械稳定性和氨基树脂混溶稳定性。以此乳液制备的涂料具有良好的综合性能:60°光泽90,硬度2H,耐冲击性(1 kg)50 cm,耐100次以上酒精擦试,耐超过96 h的常温水浸泡,耐盐雾腐蚀时间达到96 h。该羟丙乳液适用于制备低VOC水性环保金属烤漆。     

水性涂料

料2003年0303 1 37低温快干的耐溶剂水性涂料组合物及其制法:JPZooZ一322 427[日本专利公开]旧本:NipponShokubai Co.,Ltd.(Saeki,Koichiro等)一2002.11.8一8页一2001/1 3 1 082(2001.4.27);IPCCOgDZOI/00 题述组合物含水溶性阴离子树脂(数均相对分子质量)10()())、阳离子树脂(数均相对分子质量600一5 000 000)、多价金属化合物和颜料。例如,将30%(固体分计,下同)水溶‘}生阴离子苯乙烯一丙烯酸树脂(酸值=195 mg KOH/g、Tg=70 OC·Mw=12 000)31.3份、46%水可分散阴离子苯乙烯一丙烯酸树脂(酸值=55 mg KOH/g、瑰二37℃)9 .2份、5…     

双组分水性丙烯酸酯聚氨酯涂料的改性及影响因素研究进展

介绍了用于双组分水性聚氨酯涂料的羟基丙烯酸酯树脂分散体(A组分)和多异氰酸酯(B组分)的改性进展;综述了丙烯酸酯树脂分散体的活性基、酸值、羟值、玻璃化温度Tg、中和剂、中和度、溶剂以及多异氰酸酯等因素对双组分水性丙烯酸酯聚氨酯涂料性能的影响;提出了双组分水性丙烯酸酯聚氨酯涂料的发展趋势。     

丙烯酸阳极电泳涂料的制备及其性能研究

本文主要采用溶液聚合法,以丙烯酸(AA)、甲基丙烯酸甲酯(MMA)、丙烯酸丁酯(BA)、苯乙烯(St)、丙烯酸β-羟基丙酯(2-HPA)为单体,异丙醇为溶剂合成了一种丙烯酸阴极电泳涂料,并考察了中和剂的种类,电泳电压,电泳极距、电泳时间等方面对电泳后漆膜性能的影响。实验表明:13.5 g AA,27 g MMA、14 g St、38 g BA、2-HPA5.5 g,中和剂为三乙醇胺时合成的树脂在电泳电压为3 V,电泳时间为240 s,电泳极距为3 cm性能最佳。     

双重交联型丙烯酸树脂改性水性醇酸树脂的合成研究

采用偏苯三酸酐制备含水性醇酸树脂,然后用丙烯酸酯单体对其进行杂化改性,并用其制成了金属防锈涂料。确立了合成改性水性醇酸树脂的最佳配方:杂化体酸值在40~45 mg KOH/g(树脂),马来酸酐含量8%,丙烯酸树脂的T_g设定在25~30℃,交联单体双丙酮丙烯酰胺(DAAM)用量在5%,醇酸树脂油度为50%~55%。     

水性光固化丙烯酸酯聚丙烯酸酯的合成研究

以甲基丙烯酸甲酯(MMA)、甲基丙烯酸(MAA)、丙烯酸正丁酯(BA)等为原料制备出羧基型丙烯酸酯树脂;然后,滴加甲基丙烯酸缩水甘油酯(GMA),与丙烯酸酯树脂进行接枝反应;最后,在减压条件下脱除溶剂,加入中和剂进行中和,加水进行分散,制备得到了水性光固化丙烯酸酯聚丙烯酸酯树脂。实验发现:引发剂用量为6%、催化剂用量为2.5%、阻聚剂为2%、甲基丙烯酸缩水甘油酯(GMA)用量为15%、酸值为50 mg KOH/g,接枝反应温度为110℃时,得到的水性光固化丙烯酸酯聚丙烯酸酯树脂的固含量为35%,黏度约1 800 m Pa·s,树脂可获得良好的性能。     

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.     

Novel polyurethane coating technology through glycidyl carbamate chemistry

Glycidyl carbamate chemistry combines the excellent properties of polyurethanes with the crosslinking chemistry of epoxy resins. Glycidyl carbamate functional oligomers were synthesized by the reaction of polyfunctional isocyanate oligomers and glycidol. The oligomers were formulated into coatings with several amine functional crosslinkers at varying stoichiometric ratios and cured at different temperatures. Properties such as solvent resistance, hardness, and impact resistance were dependent on the composition and cure conditions. Most coatings had an excellent combination of properties. Studies were carried out to determine the kinetics of the curing reaction of the glycidyl carbamate functional oligomers with multifunctional and model amines. Detailed kinetic analysis of the curing reactions was also undertaken. The results indicated that the glycidyl carbamate functional group is more reactive than a glycidyl ether group. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, on October 27–29, 2004, in Chicago, IL.     

Highly moisture-proof polysilsesquioxane coating prepared via facile sol-gel process

A highly moisture-proof polysilsesquioxane coating was obtained from a new bis-silylated precursor, which was synthesized from 3-aminopropyltriethoxysilane (APTES) and m-xylylene diisocyanate (m-XDI) in tetrahydrofuran (THF) and verified by ¹H MAS NMR. For direct comparison purposes, an SiO₂ coating was also prepared by the Stöber method using tetraethoxysilane (TEOS) as the reactant. Interestingly, the coating obtained from the polysilsesquioxane sol exhibited a much higher moisture resistance capability than its counterpart, which was attributed to its more compact feature between nanoparticles as characterized by N₂ absorption experiment and transmission electron microscopy (TEM). Furthermore, its high transparency of about 92% showed potential for application in the protection of optical crystals.     

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.