共查询到20条相似文献,搜索用时 62 毫秒
1.
2.
以2-丙烯酰胺基-2-甲基丙磺酸(AMPS)和丙烯酰胺(AM)为原料,采用复合引发体系和绝热聚合相结合的方法在水溶液体系中合成磺化聚丙烯酰胺(SPAM),考察了单体质量分数、引发剂质量分数、单体配比、引发剂配比、pH值、聚合起始反应温度对聚合反应的影响。确定SPAM的最佳合成条件为:单体质量分数10%、引发剂质量分数0,15%、AMPS与AM质量比1.0:1、偶氮二异丁腈(AIBN)与氧化还原引发剂质量比4:1、pH值6、聚合起始反应温度40℃,在此条件下,制得的SPAM的分子量为6.13×10^6,其耐温抗盐性能明显优于采用单-氧化还原引发剂制备的SPAM及工业部分水解聚丙烯酰胺(分子量7×10^6)。 相似文献
3.
4.
环保型水性印刷光油的研究 总被引:1,自引:0,他引:1
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
5.
超临界二氧化碳中丙烯酸乙酯/3-氯丙烯接枝天然橡胶的合成与表征 总被引:1,自引:0,他引:1
采用超临界二氧化碳溶胀聚合法,以丙烯酸乙酯(EA)/3-氯丙烯(AC)为单体对天然橡胶进行了接枝改性,合成了接枝共聚物NR-g-(EA/AC)。考察了压力和引发剂用量对接枝聚合反应的影响;对NR-g-( EA/AC)进行了红外光谱、力学性能、耐溶剂性、耐燃性、硬度的测试及接枝效率和接枝率的计算,并与溶液聚合法所得NR-g-( EA/AC)的性能进行了比较。结果发现,在接枝橡胶中成功的引入了—C=O和—Cl基团;接枝橡胶的弹性模量、拉伸强度、硬度、耐燃性和耐溶剂性较天然橡胶的有了显著提高。使用溶液法和超临界二氧化碳溶胀聚合法改性天然胶乳都获得了较高的转化率和接枝率,所得产品的机械力学性能相近,但溶液法所得产品的耐溶剂性能优于后一种方法。由于超临界二氧化碳的绿色溶剂性质,超临界二氧化碳溶胀聚合法有望取代溶液聚合法而发展成一种绿色的接枝改性天然橡胶方法。 相似文献
6.
本文简述了以AC/MMA两种单体接枝改性天然胶乳的制备过程。并着重分析了改性后天然胶乳的粘度、粘接不同材质强力以及硫化胶膜的力学性质及加入氯元素后的阻燃效果。还研究了二元接枝天然胶乳并用部分水性聚氨酯乳液后使用封闭型异氰酸酯对乳液进行交联。经试验得到接枝天然胶乳与水性聚氨酯乳液的合理配比及增稠剂、固化剂合理用量的确定等。 相似文献
7.
新型共聚物防垢剂MA-AA-MAC的合成研究 总被引:1,自引:1,他引:0
以顺丁烯二酸酐、丙烯酸和丙烯酸甲酯为原料,以过硫酸铵为引发剂,合成了水溶性聚合物防垢剂MA-AA-MAC。研究了单体配比、引发剂用量、共聚反应时间、共聚反应温度对阻硫酸钡垢性能的影响,得到了最佳合成工艺,其单体配比为nMA:nAA:nMAC=1:0.8:0.6,引发剂占单体总质量的10%(质量分数),聚合反应温度85℃,聚合反应时间4h。对硫酸钡垢防垢率可达到90.1%。 相似文献
8.
采用先酯化后共聚的方法合成聚羧酸系减水剂,考察以甲基丙烯酸(MMA)和甲氧基聚乙二醇(MPEG)为原料酯化合成大单体甲氧基聚乙二醇甲基丙烯酸酯(MPEGMA)过程中阻聚剂对苯二酚用量、酸醇摩尔比、反应温度等对酯化率的影响.以犬单体MPEGMA与马来酸酐、MMA和2-丙烯酰胺基-2-甲基丙烷磺酸共聚合成聚羧酸类减水剂,考察减水剂合成过程中MPEG相对分子质量和引发剂过硫酸铵用量以及减水剂掺量对减水剂性能的影响.结果表明:阻聚荆质量分数为0.4%、酸醇摩尔比为1.5:1、反应温度为120℃时,酯化率可达到92.3%.当MPEG相对分子质量为1000、引发剂的质量分数为5%,合成的减水剂掺量质量分数为0.3%时,水泥的净浆流动度可达281mm. 相似文献
9.
10.
氯化聚丙烯/MMA/BA/MAA接枝共聚物的合成 总被引:2,自引:0,他引:2
采用溶液法用混合单体甲基丙烯酸甲酯(MMA)、丙烯酸丁酯和2-甲基丙烯酸(MAA)对氯化聚丙烯(cmm)进行接枝改性,考察了反应温度、反应时间、引发剂浓度和单体浓度等因素对接枝率的影响,并对接枝产物进行了傅立叶变换红外光谱分析。确定了理想的工艺条件:反应温度为105℃,反应时间为5h,m(CPP)/m(单体)/m(BPO)为1:0.3:0.0:3。 相似文献
11.
12.
M. S. J. Simmonds W. M. Blaney F. Delle Monache M. Marquina Mac-Quhae G. B. Marini Bettolo 《Journal of chemical ecology》1985,11(12):1593-1599
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.
Cheng-Le Zhao Shane Porzio Alan Smith Haiyan Ge H. T. Davis L. E. Scriven 《Journal of Coatings Technology and Research》2006,3(2):109-115
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
15.
16.
17.
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. 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.
中蓝晨光化工研究院有限公司《塑料工业》编辑部 《塑料工业》2009,37(3)
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.
中蓝晨光化工研究院《塑料工业》编辑部 《塑料工业》2007,35(3):1-25,67
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