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1.
制备出一种新型聚氨酯漆包线漆。将顺酐、乙二醇、甘油进行共缩聚,合成出一种顺酐聚酯多元醇,然后与异氰酸酯交联剂配合制备出漆包线漆。研究表明:采用顺酐、甘油、乙二醇在200℃反应约3 h,再采用二甲苯共沸回流40 min,制备出一种酸值1.2、熔点40~50℃、数均分子质量4 396、无色透明的顺酐聚酯多元醇;所制备漆包铜线的直焊温度为330℃,软化击穿温度为230℃,击穿电压5.3 kV,介质损耗曲线的拐点温度值达到145℃。  相似文献   

2.
发展了一种聚酯多元醇,可望应用于制备新型的直焊性耐热漆包线漆。采用间苯二甲酸、己二酸、乙醇胺或乙二醇、三乙醇胺或甘油,通过熔融共缩聚合成一系列聚酯多元醇,然后用甲醚化氨基树脂及溶剂混合、配制成溶液,再涂制成漆包线。研究结果表明系列聚酯多元醇的分子量、酸值均符合漆包线漆制备的技术要求;采用乙醇胺代替乙二醇、三乙醇胺代替甘油在聚酯多元醇的合成反应中具有较高的缩聚反应活性,由此制备的聚酯多元醇具有在350℃至400℃的范围内更快速分解和分解残渣较少的特点,采用此聚酯多元醇作为主要成分、涂制的漆包线在400℃至460℃范围内下可直焊,介质损耗曲线的拐点温度可达到162℃、意味着耐热等级较高。  相似文献   

3.
以可再生资源蓖麻油制备的蓖麻油甲酯、己二酸、乙二醇为原料,钛酸四正丁酯为催化剂,经酯化、缩聚合成蓖麻油酸基聚酯多元醇,考察了反应时间、催化剂、蓖麻油甲酯对聚酯多元醇热稳定性能的影响,采用凝胶色谱(GPC)、红外光谱仪(IR)、示差扫描量热仪(DSC)对蓖麻油酸基聚酯多元醇的相对分子质量、结构、热稳定性进行了系统的表征。实验表明,在醇酸(己二酸∶乙二醇)比为1.15、催化剂质量分数0.04%~0.05%、温度180℃,真空缩聚2h的条件下,制得相对分子质量为2600~3800、分布指数(PDI)为1.89~2.44的不同蓖麻油酸含量的聚酯多元醇,蓖麻油酸基聚酯多元醇的熔点随着蓖麻油酸含量的增加而降低。  相似文献   

4.
以蓖麻油、甘油、己二酸和乙二醇为原料,酯化缩聚合成低黏度的蓖麻油聚酯多元醇,并将该蓖麻油聚酯多元醇与HDI聚异氰酸酯制备无溶剂涂料。研究了醇酸比[n(—OH):n(—COOH)]对蓖麻油聚酯多元醇及其涂层性能的影响。结果表明:在醇酸比为1.32时,蓖麻油聚酯多元醇所制涂层的耐水性、耐冲击性、耐擦伤性、柔韧性等综合性能良好。  相似文献   

5.
芳烃聚酯多元醇的合成及应用研究   总被引:2,自引:0,他引:2  
介绍了以聚对苯对二甲酸乙二醇酯残渣和二乙二醇为主要原料制备低成本芳烃聚酯多元醇的工艺路线,讨论了温度,DEG和PET残渣的摩尔比对芳烃聚酯多元醇性能的性能。试验表明,最佳反应温度为190℃-220℃,最佳摩尔比为1.22-1.34。研究了稳定剂对聚酯多元醇组合料贮存稳定性的影响,组合料贮存期在半年以上。聚酯型聚所酯硬泡的氧指数达27.5%。  相似文献   

6.
以苯酐、二甘醇为原料合成苯酐聚酯多元醇。简述了合成聚酯多元醇的工艺,对反应温度、反应时间、物料配比、真空度、出水速率控制、催化剂用量等对合成苯酐聚酯多元醇的影响因素进行了研究。结果表明,当反应温度控制在230℃左右,n(二甘醇)∶n(苯酐)=(1.15~1.20)∶1,真空度大于0.09MPa,催化剂质量分数为0.04%(以苯酐计)时,合成的苯酐聚酯多元醇可以满足聚氨酯胶黏剂的应用要求。  相似文献   

7.
以苯酐、己二酸和甲基丙二醇为原料合成了聚酯多元醇,在基本相同的反应条件下,分别采用乙二醇锑Sb2(EG)3、三氧化二锑(Sb2O3)、醋酸锌Zn(Ac)2、钛酸四丁酯(TBT)和钛酸四异丙酯(TPT)等催化剂进行聚酯多元醇的合成反应。研究结果表明,在本反应体系中TPT是最佳催化剂;随着聚酯多元醇理论相对分子质量的增大,反应越难以进行,因此催化剂用量应相应增加,但其质量分数以不超过0.04%为宜。  相似文献   

8.
低溶剂微支链聚酯树脂是一种新型的具有一定反应能力的增塑剂。是以乙二醇、己二酸为反应主体,加入一些能形成支链的反应物,通过缩聚合成聚合物,同时加入单元酸单体来调节控制分子量,从而得到低分子量达到低溶剂的要求。通过实验得出反应物投料比例:29%乙二醇﹑56%己二酸﹑10%苯甲酸﹑3%甘油、2%苯酐和少量回流用溶剂二甲苯;酯化反应温度为210~220℃、反应时间为5~6h。达到指标后,再采用减压脱溶剂把回流物脱出,能制得较好的低溶剂微支链聚酯树脂。  相似文献   

9.
以废聚酯材料、季戊四醇、豆油酸、苯酐等为主要原料制备了高固体分聚酯多元醇树脂,再与高固体分聚氨酯树脂配制而成高固体聚酯型聚氨酯漆.讨论了酯化工艺、催化剂种类、升温速率和醇解温度对醇解反应的影响,并分析了经济效益.结果表明,采用二月桂酸二丁基锡为催化剂,以在240~250℃下用甘油醇解、酯化,制备的高固体分聚酯多元醇树脂固体分为(80±2)%,羟值为(100±10)mgKOH/g.该树脂与聚氨酯树脂组成的双组分聚酯型聚氨酯漆操作方便、工艺稳定、质量达标、经济效益显著,为废聚酯的回收利用找到了新的途径,又为高档漆提供了价廉的原料,增加了社会效益.  相似文献   

10.
(三)聚酯聚酯是聚氨酯工业中最早应用的多元醇,首先由西德拜耳公司开始这方面研究工作。现在主要应用于特种软质泡沫塑料、涂料、粘接剂和橡胶类型的聚氨酯材料,聚酯型聚氨酯一般比聚醚型具有较好的耐热耐臭氧性、粘合性和机械强度。但由于其粘度大,给工艺操作带来较大困难,而且价格较高,因而近年来发展比例上有下降的趋势。制造方法主要是采用二元酸和多元醇缩聚而成聚酯,通常采用的二元酸有苯酐、已二酸、顺丁烯二酸、卤代苯二甲酸酐等有机酸,多元醇一般为乙二醇、丙二醇、一缩乙  相似文献   

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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   

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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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