首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 640 毫秒
1.
聚丙烯酰胺—淀粉接枝共聚物的合成与应用   总被引:18,自引:0,他引:18  
王欣 《辽宁化工》2001,30(4):164-165,176
介绍了一种具有开发和应用前景的新型高分子化合物的原理和方法,以淀粉为原料,使之与聚丙烯酰胺经Hofmann重排的产物直接反应,合成接枝共聚物(St-g-PAM),并且在印梁废水处理及造约助剂等方面对产品的使用效果进行了应用研究。  相似文献   

2.
以玉米淀粉和丙烯酰胺为原料,过硫酸铵为引发剂,用水溶液聚合法合成了淀粉接枝丙烯酰胺絮凝剂。研究了反应温度、反应时间和引发剂用量等反应条件对单体转化率、接枝率、接枝效率、絮凝性能的影响。结果表明:在淀粉与丙烯酰胺单体的质量比为1∶2,反应温度为45℃,反应时间为3h,引发剂用量为单体的1.25%时,产物接枝效率、单体转化率、接枝率最高,絮凝性能较优。  相似文献   

3.
马凤国  谭惠民 《现代化工》2006,26(Z2):101-104
通过接枝共聚制备羧甲基纤维素接枝聚丙烯酰胺(CMC-g-PAM)树脂,进而通过Mannich反应制备羧甲基纤维素接枝季铵化聚丙烯酰胺阳离子接枝共聚物(CMC-g-CPAM).通过红外光谱表征了产物的结构.采用静态法测定该阳离子接枝共聚物对水溶性直接染料的吸附脱色性能.结果表明,该树脂对直接染料有很好的吸附脱色性能,脱色率可达98%左右.  相似文献   

4.
淀粉接枝丙烯酰胺的合成及其絮凝性能的研究   总被引:3,自引:0,他引:3  
以玉米淀粉(St)和丙烯酰胺(AM)单体为原料,采用过硫酸钾引发剂合成了淀粉接枝丙烯酰胺共聚物(St-g-AM)。用红外光谱对接枝共聚物进行了结构表征,用粘度法测定了分子量。讨论了聚合反应的各个因素对接枝共聚反应的影响,考察了接枝共聚物的絮凝性能。结果表明,以接枝效率为考察目标,其最佳的合成工艺为:引发剂的浓度为0.07 g/100 mL,淀粉与丙烯酰胺的质量比为1∶2.2,反应温度为65℃,反应时间3 h。淀粉接枝丙烯酰胺共聚物比430万分子量的聚丙烯酰胺(PAM)对高岭土水样的絮凝性能更好,当接枝共聚物的投加量为6 mg/L时,对高岭土水样的浊度去除率达到81.77%。最佳条件所合成出的淀粉接枝丙烯酰胺的分子量为75万。  相似文献   

5.
介绍了正交试验在淀粉接枝丙烯酰胺聚合物阳离子化产物合成中的应用,通过正交试验得出了淀粉接枝丙烯酰胺聚合物阳离子化产物对煤矿废水处理的最优合成条件.引发剂:1.0×10-3mol/L;单体质量比:1:2;原料配比:1.0:1.0:1.5;反应温度65℃.  相似文献   

6.
周建武 《广东化工》2007,34(9):69-72
首先应用水溶液聚合方法合成了星型聚丙烯酰胺(SPAM),然后将星型聚丙烯酰胺与NaOCl进行氯胺化反应,经Hofmann重排部分酰胺基转变为活泼的异氰酸酯基团,与亚麻纤维素大分子上的-OH基反应,在亚麻纤维素的大分子上接枝了SPAM。采用正交实验的方法讨论了聚合体系温度,反应时间,SPAM浓度对共聚物接枝率的影响,通过染色实验考查了改性后亚麻织物的染色性能。  相似文献   

7.
首先应用水溶液聚合方法合成了星型聚丙烯酰胺(SPAM),然后将星型聚丙烯酰胺与NaOCl进行氯胺化反应,经Hofmann重排部分酰胺基转变为活泼的异氰酸酯基团,与亚麻纤维素大分子上的-OH基反应,在亚麻纤维素的大分子上接枝了星型聚丙烯酰胺(SPAM)。采用正交实验的方法讨论了聚合体系温度、反应时间、星型聚丙烯酰胺(SPAM)浓度对共聚物接枝率的影响,通过染色实验考查了改性后亚麻织物的染色性能。  相似文献   

8.
宋辉 《应用化工》2010,39(6):870-873
用自制的引发剂,通过溶液聚合反应合成了淀粉、丙烯酰胺(AM)、二甲基二烯丙基氯化铵(DMDAAC)季铵型淀粉基强阳离子高分子聚合物,并通过红外光谱对其进行了表征。最佳反应条件为:接枝共聚反应引发剂用量为0.15%,m(淀粉)∶m(AM+DMDAAC)=3∶7,m(AM)∶m(DMDAAC)=7∶3,反应时间4 h,反应温度50℃。产物对油田污水中油和固体悬浮物的去除率优于阳离子聚丙烯酰胺(CPAM)。  相似文献   

9.
亚麻的染色性差和色牢度低一直是制约开发高档亚麻织物产品的主要因素.研究表明通过接枝共聚阳离子型聚丙烯酰胺(PDA)能够明显改善亚麻的染色性和色牢度.采用水溶液聚合方法合成PDA,将PDA与NaOCl进行氯胺化反应,经Hofmann重排使部分酰胺基转变为活泼的异氰酸酯基团,与亚麻纤维素大分子上的-OH基反应,在亚麻纤维素的大分子接枝上阳离子聚丙烯酰胺(PDA).采用正交实验的方法研究聚合体系温度、反应时间、PDA浓度对共聚物接枝率的影响,通过染色实验考查改性后亚麻织物的染色性能.  相似文献   

10.
星形聚丙烯酰胺接枝淀粉的合成及应用   总被引:3,自引:2,他引:1  
樊小辉  孙挺  吴全才  姜涛 《化工进展》2006,25(5):577-580,584
介绍了应用水溶液聚合方法合成了星形聚丙烯酰胺(SPAM)的方法。采用正交实验方法研究了不同的引发剂用量、相对分子质量调节剂用量、聚合体系温度对SPAM特性黏数的影响,从中优化出最佳反应条件为单体质量分数为15%,聚合温度为35 ℃,引发剂质量分数为(相对单体质量,下同)0.04%,螯合剂为0.005%,抗交联剂为0.015%,聚合体系pH值为5,得到的星形聚丙烯酰胺特性黏数为989.2 mL/g。星形聚丙烯酰胺在35℃进行氯胺化反应并加到糊化好的淀粉溶液中,在40~50 ℃下反应40 min,即得到星形聚丙烯酰胺接枝淀粉絮凝剂。结果说明,星形聚丙烯酰胺接枝淀粉絮凝剂溶解性好、絮凝能力强,具有良好的絮凝效果。  相似文献   

11.
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   

15.
16.
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   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号