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1.
负离子型聚氨酯离聚体水分散过程的相反转   总被引:1,自引:0,他引:1  
用异佛尔酮二异氰酸酯、聚己二酸新戊二醇酯和二羟甲基丙酸(DMPA)合成了负离子型聚氨酯离聚体.研究了该类离聚体在水分散过程中的相反转变化,讨论了DMPA质量分数和水分散温度对相反转过程的影响。结果表明,DMPA质量分数增加或水分散温度提高,可使相反转所需的时间缩短,分散液粒子粒径变小,粒径分布更均匀,黏度增大。水分散温度的作用较DMPA更为明显。差示扫描量热分析表明,水分散过程破坏了亲水性硬链段的有序性。傅里叶变换红外光谱分析表明,聚氨酯水分散液用乙二胺扩链后.脲羰基的氢键化程度随DMPA质量分数的增加、水分散温度的提高而提高。  相似文献   

2.
用异佛尔酮二异氰酸酯(IPDI)、丙三醇、聚四氢呋喃醚二醇(PTMG)、甲基丙烯酸羟乙酯(DMPA)、季戊四醇三丙烯酸酯(PETA)等原料合成了具有高交联度的多官能度紫外光固化聚氨酯丙烯酸酯(PUA)水乳液。采用国标GB12009.4—89,FT-IR,13C NMR,DMA,AFM等方法对PUA预聚体合成过程和聚合物乳液(涂膜)进行了测试和表征,考察了n(IPDI)∶n(HO—OH)∶n(丙三醇)、DMPA质量分数、pH值等对乳液及涂膜性能的影响。结果表明,随着丙三醇质量分数增大,PUA光固化速率、耐溶剂性、膜硬度提高、吸水率降低;随着DMPA质量分数的增加,PUA涂膜硬度、吸水率增强,乳胶粒径越来越小;随着中和度增大,乳液逐渐由云雾状趋向透明,粘度下降。当n(IPDI)∶n(HO—OH)∶n(丙三醇)=9∶6∶1,w(丙三醇)=2%左右,DMPA质量分数为4.6%,中和度为90%时,乳液储存稳定(30 d),涂膜光固化速率达到7 s,附着力为1,硬度为3 H,耐水性、耐化学品性更佳。  相似文献   

3.
以TDI、HPA、聚醚或聚酯二元醇、亲水性单体DMPA等为原料,以丙烯酸酯单体为溶剂进行预聚;在水中自乳化形成的PU乳液为种子,不外加乳化剂,进行PU/PA种子乳液聚合,形成的PUA水分散液均一稳定,成膜性好。运用TEM、DSC等手段对PUA水分散液进行了表征。  相似文献   

4.
选择丙烯酸酯作为自由基型预聚物,3,4–环氧环己基甲基–3,4环氧环己基甲酸酯作为阳离子型预聚物,三丙二醇二丙烯酸酯为活性稀释剂,2,2–二甲基–α–羟基苯乙酮和三芳基硫鎓盐为光引发剂来制备一种混杂固化光敏树脂。将聚氨酯丙烯酸酯(PUA)加入到上述制备的光敏树脂中,探究PUA作为辅助预聚物对光敏树脂性能的影响,用超声分散法制备了纳米氧化石墨烯(GO)改性光敏树脂复合材料。当PUA的质量分数为20%时,力学性能最优;GO对光敏树脂的力学性能有改善的作用,拉伸强度从17.84 MPa最大增强至27.84 MPa,提高了56%;且该混合体系的体积收缩率在3%左右,线收缩率也很小。  相似文献   

5.
UV涂料对光纤附加光衰减的影响   总被引:1,自引:0,他引:1  
采用双酚A环氧丙烯酸酯(EA)和聚氨酯丙烯酸酯(PUA)共混,加入活性稀释剂、光引发剂、颜料等制备了紫外光固化光纤涂料。讨论了EA与PUA的配比,预聚物与活性稀释剂的配比以及光引发剂及颜料的含量对光纤带附加光衰减的影响。结果表明:当EA/PUA为1∶1.5(质量比),预聚物质量分数为52%,活性稀释剂质量分数为28%,光引发剂质量分数为14%,颜料质量分数为1.5%时,光纤具有最小的附加光衰减值。  相似文献   

6.
低亲水基丙烯酸酯-聚氨酯复合乳液涂膜的热分析研究   总被引:1,自引:0,他引:1  
以异佛尔酮二异氰酸酯(IPD I)、聚已二酸-1,4丁-二醇酯(PBA)、二羟甲基丙酸(DMPA)、丙烯酸酯(PA)为主要原料,采用自乳化工艺制备了固体质量分数均为40%,亲水基团(DMPA的羧基)占固体质量百分数为1%的一系列稳定的聚氨酯-丙烯酸酯复合乳液(PUA);用热重分析(TG)、示差扫描量热分析(DSC)、动态机械热分析(DMA)方法研究PBA的相对分子质量、聚氨酯与丙烯酸酯的质量分数比(PU/PA)对PUA膜热性能的影响。热分析研究表明,增加PBA相对分子质量和加入适量的丙烯酸酯能提高PUA分子的有序程度,有利于PUA成膜物耐热性能的改善;随着PBA相对分子质量的增加,PU软段的非晶部分和PA的硬段相容性增强,微观相分离减小,乳液的混合能达到分子水平。  相似文献   

7.
《粘接》2016,(1)
用异辛酸锌作催化剂,以聚碳酸亚丙酯二醇和异佛尔酮二异氰酸酯(IPDI)与含羟基的环氧丙烯酸酯预聚物作主要原料,合成了适于UV固化的聚氨酯丙烯酸酯预聚物(PUA),并对PUA胶粘剂的性能进行了初步研究。结果表明,当催化剂异辛酸锌的质量分数为0.3%,阻聚剂的用量为0.08%,反应温度控制在80℃为宜,总反应时间约为7 h,可以合成稳定性好的聚氨酯丙烯酸酯预聚物,以该聚氨酯丙烯酸酯制得UV固化胶粘剂固化速度快,成膜物附着力优、强度高。  相似文献   

8.
以异佛尔酮二异氰酸酯(IPDI)、聚醚二元醇(DL-1000)、二羟甲基丙酸(DMPA)和甲基丙烯酸羟乙酯(HEMA)为主要原料合成了具有感光性能的水性聚氨酯丙烯酸酯(PUA)乳液,通过红外光谱对其结构进行了表征。其与活性稀释剂二缩三丙二醇二丙烯酸酯(TPGDA)、光引发剂混合均匀得到水性紫外光(UV)固化树脂。通过涂膜性能测试,研究了各配方组分、UV固化条件等对涂膜性能的影响。结果表明:适宜的DMPA质量分数为5.5%~6.0%,NCO/OH物质的量比为1.55∶1,TPGDA质量分数为10%,光引发剂为TPO,其用量为总树脂质量的4%,光照时间为7.0 s,以其制得的PUA树脂外观、贮存稳定性和耐黄变性良好,涂膜的综合性能最佳。  相似文献   

9.
用甲苯二异氰酸酯、聚己二酸新戊二醇酯多元醇(PDGA)、二羟甲基丙酸(DMPA)和甲基丙烯酸-2-羟乙酯合成了聚氨酯-丙烯酸酯(PUA)离聚物乳液,讨论了DMPA用量对其性能的影响。结果表明,当DMPA与PDGA的摩尔比增大时,PUA离聚物乳液的平均粒径减小,粒径分布变窄,黏度增大,稳定性提高,但DMPA用量过高时,会使具有高表面能的小粒子团聚,从而给PUA离聚物的乳液性能带来负面影响。  相似文献   

10.
高性能水性聚氨酯乳液的合成及表征   总被引:1,自引:0,他引:1  
高性能环保的丙烯酸酯改性水性聚氨酯乳液是当前涂料工业研究的一个热点。以甲苯二异氰酸酯(TDI-80)、聚醚二元醇(N210)、二羟甲基丙酸(DMPA)和甲基丙烯酸甲酯(MMA)为主要原料,采用原位乳液聚合法,先制得水性聚氨酯(PU)预聚物/乙烯基单体混合物,然后加入引发剂,自由基乳液聚合得到聚氨酯.丙烯酸酯(PUA)复合乳液。研究发现PUA乳液的性能及外观与NCO/OH比值、二羟甲基丙酸(DMPA)含量、中和度等密切相关。当NCO/OH的摩尔比为1,3~1.4,—COOH含量约2.6%(质量分数),中和度=90%-100%时,所得PUA乳液外观好、性能佳。  相似文献   

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12.
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.  相似文献   

13.
14.
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.  相似文献   

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17.
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.  相似文献   

18.
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.  相似文献   

19.
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.  相似文献   

20.
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。  相似文献   

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