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1.
戴祖贵 《粘接》2010,31(10):56-59
通过半种子连续乳液聚合工艺,以过硫酸铵为引发剂,以非离子和阴离子乳化剂为复合乳化剂,加入一定量的保护胶体,利用叔碳酸乙烯酯(Veova10)和丙烯酸异辛酯(2-EHA)为改性单体,合成了高固含量的改性聚醋酸乙烯酯乳液。研究了乳化剂用量,阴/非离子乳化剂质量比,叔碳酸乙烯酯、丙烯酸异辛酯和保护胶体用量对合成乳液的稳定性、黏度及吸水性的影响。研究结果表明,乳化剂质量分数为3.0%,阴/非离子乳化剂质量比为1:2,叔碳酸乙烯酯质量分数为20%,丙烯酸异辛酯质量分数为10%,保护胶体质量分数为0.25%时,乳液具有较好的稳定性、耐水性和成膜性。  相似文献   

2.
乙烯基三乙氧基硅烷改性丙烯酸乳液的研究   总被引:1,自引:0,他引:1  
以丙烯酸酯、乙烯基硅烷为主要原料,以OP-10和十二烷基硫酸钠(SDS)为复合乳化剂,采用连续滴加法进行乳液聚合,制备了有机硅改性丙烯酸酯乳液。实验结果表明:当甲基丙烯酸甲酯(MMA)与丙烯酸丁酯(BA)的质量比为1.2~1.0、有机硅单体用量占单体质量分数的3%~10%、复合乳化剂(OP-10:SDS=3:1)占单体质量分数的4%。5%时,可制得性能良好的硅丙乳液。  相似文献   

3.
有机硅改性苯丙乳液的制备及其性能研究   总被引:3,自引:0,他引:3  
以丙烯酸丁酯、苯乙烯、丙烯酸、乙烯基三乙氧基硅烷为原料合成了有机硅改性苯丙乳液。讨论了聚合工艺、聚合温度、乙烯基三乙氧基硅烷的加入量与加入方式、乳化剂用量和配比对乳液综合性能的影响;并利用红外光谱和X射线衍射对共聚物的结构进行了表征。结果表明,合成有机硅改性苯丙乳液的较佳工艺条件为:采用预乳化法,复合乳化剂[m(OP—10):m(SDS)=5:1~2:1]的质量分数为3%~5%,乙烯基三乙氧基硅烷的质量分数为2%~6%,聚合温度75~80℃。在此条件合成的乳液的稀释稳定性、冻融稳定性、钙离子稳定性、贮存稳定性好,与普通苯丙乳液相比,乳胶膜的吸水率明显降低。  相似文献   

4.
复合交联型水性纸塑复膜胶的研制   总被引:1,自引:0,他引:1  
郑军 《化学与粘合》2008,30(3):57-59
介绍了一种水性纸塑复膜胶的制备方法。以丙烯酸丁酯、苯乙烯、丙烯酸和交联型功能单体为主要原料,采用单体预乳化种子乳液聚合工艺进行合成。讨论了单体的选择及配比对乳液性能和纸塑复合的影响、乳化剂对乳液稳定性的影响、引发剂对单体转化率的影响。结果表明:软硬单体丙烯酸丁酯与苯乙烯最佳配比是1.6~2.3:1,乳化剂和引发剂最佳用量分别为总单体量的0.98%和0.60%。制得的乳液粒径细腻、固含量高、黏度适中且稳定性好。  相似文献   

5.
环保型水性印刷光油的研究   总被引:1,自引:0,他引:1  
唐楷  颜杰 《辽宁化工》2009,38(8):520-523
以甲基丙烯酸甲酯(MMA)、丙烯酸丁酯(BA)、丙烯酸甲酯(MA)、苯乙烯(St)等为单体,以过硫酸钾为引发剂,以十二烷基硫酸钠(SDS)、聚乙二醇辛基苯基醚(OP-10)为乳化剂,通过预乳化种子聚合法获得水性乳液型上光油。探讨了乳化剂用量和配比、引发剂用量、反应温度和时间、后续单体滴加时间、保温反应时间、搅拌速度及中和剂对乳液综合性能的影响。通过固化成膜试验对水性上光油的光泽度、耐磨性、耐水性等性能测定。结果表明:乳化剂用量为乳液的2.0%~3.0%(质量分数),阴/非离子乳化剂配比为1:2,引发剂质量分数为单体的0.55%,反应温度78—84℃,反应时间4h,后续滴加单体时间为90min,保温时间2.0h,搅拌速率为120r/min,使用NaHCO3作为中和剂时乳液性能最佳。主要技术指标:光泽度为92;固含量为46%。  相似文献   

6.
有机硅接枝改性纯丙复合乳液的合成及性能研究   总被引:1,自引:0,他引:1  
采用两步法聚合工艺制备了含双键有机硅氧烷官能团单体与D4进行乳液缩聚后再与(甲基)丙烯酸酯类单体进行自由基接枝共聚的改性纯丙复合乳液,考查了聚合过程的乳化剂体系、反应温度和时间对单体转化率的关系及对乳液稳定性的影响。得到最佳工艺条件为:第一步采用阴离子型乳化剂DSBA/与非离子乳化剂聚氧乙烯壬基苯基醚系列并用,使含双键有机硅氧烷官能团单体先与D4进行乳液缩聚,反应温度为85~90℃,平衡反应时间3~4小时,中和后得到有机硅预聚体乳液。第二步采用阴离子型乳化剂MS-1与非离子乳化剂NP-40并用的复合乳化剂及APS引发剂进行引发,将第一步反应生成的乳液滴入此段反应过程进行接枝共聚,反应温度为75~80℃,反应时间5~6小时,最终得到有机硅接枝改性纯丙复合乳液。在固定复合乳液中乳化剂总含量≤2.5%的前提下,复合乳化剂的HLB值在12.0左右为宜,确定了各单体的比例为m(BA):m(MMA):m(硅单体)为47:44:9,测试结果表明改性复合共聚乳液粘度适中,为热力学稳定体系,其机械稳定性、化学稳定性均达到要求,用改性乳液配制的外墙乳胶涂料的性能较普通市售纯丙乳液具有较大程度的提高。  相似文献   

7.
有机硅/聚醚复合乳液消泡剂的配制   总被引:2,自引:2,他引:2  
将二甲基硅油、聚醚、复合乳化剂和助乳化剂复配 ,制得有机硅 /聚醚复合乳液消泡剂。讨论了乳化剂、助乳化剂的种类及用量、二甲基硅油规格及用量对乳液稳定性和消泡效果的影响。较佳配方为1 0 0份复合乳液消泡剂中粘度 ( 2 5℃ )为 5 0 0mPa·s的二甲基硅油 1 0~ 2 0份、羟值为 40~ 5 6mgKOH/g的聚醚 1 0~ 2 0份、复合乳化剂 4 5份、助乳化剂 1~ 3份 ,乳化温度 60℃。对于脱墨液、草浆黑液、涂布剂和阳离子松香施胶剂 ,有机硅 /聚醚复合乳液消泡剂的应用效果优于单纯的聚醚消泡剂和有机硅消泡剂 ,消泡速度更快 ,用量更少。  相似文献   

8.
高固体分无凝胶丙烯酸酯乳液合成工艺探讨   总被引:1,自引:0,他引:1  
为制备高固体分无凝胶丙烯酸酯乳液,探讨了聚合方法,单体和引发剂的加料方式,乳化剂用量和种类,以及保护胶体种类对丙烯酸酯乳液性能的影响。结果表明:全部预乳化效果最佳,4h内无凝胶产生;半连续滴加较一次性或分批加入更有利于乳液体系稳定;采用阴离子与非离子乳化剂复配及加入保护胶体有利于提高聚合体系的固含量。筛选出最佳的制备工艺条件:采用全部预乳化、半连续种子乳液聚合;以十二烷基硫酸钠(SDS)与烷基酚聚氧乙烯醚(OP-10)为复合乳化剂(质量比为1:1),其用量为3%;保护胶体量为0.8%;引发剂量为0.3%;反应温度为78℃;反应时间为4h;搅拌速率为400r/min。此条件下可合成固含量达60.03%的带蓝光乳白色丙烯酸酯乳液。  相似文献   

9.
大粒径丁苯胶乳的合成研究   总被引:1,自引:0,他引:1  
合成了大粒径丁苯胶乳(SBR),研究了乳化剂、引发剂、固含量、电解质及单体加入方式对丁苯胶乳粒径的影响。结果表明:乳化剂用量、固含量、电解质用量及单体加入方式是控制SBR粒径大小的关键性因素,当乳化剂用量为1.6%~2.4%,引发剂用量低于0.25%,电解质用量为1.5%~2.0%,固含量为50%~55%时,可建立稳定的乳液体系,合成粒经在260~300nm的丁苯胶乳;采用种子半连续加料方式有利于增大SBR的粒径。  相似文献   

10.
叔碳酸乙烯酯改性醋酸乙烯酯乳液的研制   总被引:10,自引:2,他引:10  
采用半种子连续乳液聚合的方法,以过硫酸钾为引发剂,以十二烷基硫酸钠和OP—10复配为乳化剂,合成了叔碳酸乙烯酯/醋酸乙烯酯共聚乳液。研究了乳化剂的用量、阴离子/非离子质量比和叔碳酸乙烯酯用量对乳液性能的影响;引发剂用量、聚合温度、种子单体加入量以及单体进料速率对聚合过程的影响。乳化剂用量为3%、阴离子/非离子为1:1、叔碳酸乙烯酯用量为30%;聚合温度为76℃、引发剂用量为0.4%、种子加入量为10%、进料周期为4h,聚合过程稳定,乳液性能良好。  相似文献   

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Scentless plant bugs (Heteroptera: Rhopalidae) are so named because adults of the Serinethinae have vestigial metathoracic scent glands. Serinethines are seed predators of Sapindales, especially Sapindaceae that produce toxic cyanolipids. In two serinethine species whose ranges extend into the southern United States,Jadera haematoloma andJ. sanguinolenta, sequestration of host cyanolipids as glucosides renders these gregarious, aposematic insects unpalatable to a variety of predators. The blood glucoside profile and cyanogenesis ofJadera varies depending on the cyanolipid chemistry of hosts, and adults and larvae fed golden rain tree seeds (Koelreuteria paniculata) excrete the volatile lactone, 4-methyl-2(5H)-furanone, to which they are attracted.Jadera fed balloon vine seeds (Cardiospermum spp.) do not excrete the attractive lactone. Loss of the usual heteropteran defensive glands in serinethines may have coevolved with host specificity on toxic plants, and the orientation ofJadera to a volatile excretory product could be an adaptive response to save time.Mention of a commercial product does not consititute an endorsement by the USDA.  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   

14.
2008~2009年世界塑料工业进展   总被引:4,自引:1,他引:3  
收集了2008年7月~2009年6月世界塑料工业的相关资料,介绍了2008~2009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、环氧树脂、不饱和聚酯树脂)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   

15.
It is well established that a wide range of drugs of abuse acutely boost the signaling of the sympathetic nervous system and the hypothalamic–pituitary–adrenal (HPA) axis, where norepinephrine and epinephrine are major output molecules. This stimulatory effect is accompanied by such symptoms as elevated heart rate and blood pressure, more rapid breathing, increased body temperature and sweating, and pupillary dilation, as well as the intoxicating or euphoric subjective properties of the drug. While many drugs of abuse are thought to achieve their intoxicating effects by modulating the monoaminergic neurotransmitter systems (i.e., serotonin, norepinephrine, dopamine) by binding to these receptors or otherwise affecting their synaptic signaling, this paper puts forth the hypothesis that many of these drugs are actually acutely converted to catecholamines (dopamine, norepinephrine, epinephrine) in vivo, in addition to transformation to their known metabolites. In this manner, a range of stimulants, opioids, and psychedelics (as well as alcohol) may partially achieve their intoxicating properties, as well as side effects, due to this putative transformation to catecholamines. If this hypothesis is correct, it would alter our understanding of the basic biosynthetic pathways for generating these important signaling molecules, while also modifying our view of the neural substrates underlying substance abuse and dependence, including psychological stress-induced relapse. Importantly, there is a direct way to test the overarching hypothesis: administer (either centrally or peripherally) stable isotope versions of these drugs to model organisms such as rodents (or even to humans) and then use liquid chromatography-mass spectrometry to determine if the labeled drug is converted to labeled catecholamines in brain, blood plasma, or urine samples.  相似文献   

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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   

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