复合引发体系制备阳离子絮凝剂在污水处理中的应用研究

采用复合引发体系用甲基丙烯酰氧乙基三甲基氯化铵(DMC)和丙烯酰胺(AM)水溶液共聚制备了阳离子高分子絮凝剂P(DMC-AM).并将其应用于十堰市污水厂废水处理,探讨了其投加量和废水pH对CODCr、浊度、色度去除率的影响.结果表明,当处理的废水pH为7.5,P(DMC-AM)投加质量浓度为8 mg/L时,废水的CODCr去除率达到88%以上,色度和浊度的去除率均达到95%以上.     

复合引发体系制备阳离子聚丙烯酰胺及其应用

将复合引发体系用于甲基丙烯酰氧乙基三甲基氯化铵(DMC)和丙烯酰胺(AM)水溶液共聚,制备了阳离子聚丙烯酰胺类絮凝剂P(DMC-AM)。探讨了单体质量分数、引发剂用量,反应时间等因素对聚合物特性粘数的影响,并利用红外光谱对其结构进行了表征。实验结果表明,最佳反应条件为:引发剂质量分数为0.014%,单体质量分数30%。DMS与AM的质量比为1∶1,pH值为5.5,反应时间为5￣6h。将其应用于十堰市污水厂废水,对废水的CODCr去除率达到80%以上,对色度和浊度的去除率达到95%以上,是一种性能优良的絮凝剂。     

甲基丙烯酰氧乙基三甲基氯化铵聚合物合成和应用研究进展

甲基丙烯酰氧乙基三甲基氯化铵聚合物是一类带有季铵盐基团的高分子聚电解质,具有带正电荷、水溶性好、特征黏度易于控制、高效无毒等特点,广泛应用于石油开采、造纸、纺织、废水和污泥处理等行业中。首先,概述了聚甲基丙烯酰氧乙基三甲基氯化铵(PDMC)在提高产物特征黏度方面的合成研究进展,指出了PDMC在分子结构上的最新研究方向;然后,介绍了共聚物聚甲基丙烯酰氧乙基三甲基氯化铵-丙烯酰胺〔P(DMC-AM)〕的合成进展,重点探讨了溶液聚合法、乳液聚合法和其他聚合法对聚合物序列结构和特征黏度影响的研究进展;接着,对比不同性质的污泥处理实例,阐述了污泥性质对共聚物P(DMC-AM)絮凝性能的影响规律;最后,归纳了P(DMC-AM)在合成和应用中的问题并对未来的发展趋势进行了展望。     

P(DMC-AM)高分子絮凝剂的制备及絮凝性能

论述了高相对分子质量阳离子聚(甲基丙烯酰氧乙基三甲基氯化胺-丙烯酰胺)〔P(DMC-AM)〕絮凝剂的制备及絮凝性能研究,讨论了多种因素对絮凝效果的影响。当w(单体)=40%;m(DMC)∶m(AM)=3∶2;m(引发剂)∶m(AM)=0.09∶100时,得到的阳离子型P(DMC-AM)高分子絮凝剂对造纸污水及生活废水有明显的絮凝作用。P(DMC-AM)的最佳絮凝条件为:相对分子质量为430~460万,用量为1.1~1.3 mg/L,阳离子度为33%~38%,废水pH=3~7;在造纸污(废)水体系中,CODC r的去除率可达89%以上,透光率接近100%;采用电子扫描电镜观察絮凝物,结果发现,絮凝后的纤维间可形成多个物理吸附点,交叉网状结构明显,网络编织致密,说明桥联及电中和作用明显,絮凝效果优异。     

一种阳离子聚丙烯酰胺水处理剂的合成与评价

以丙烯酰胺(AM)、甲基丙烯酰氧乙基三甲基氯化铵(DMC)为单体原料,采用(NH4)-2S208/NaHSO3和偶氮类化合物组成的复合引发体系,通过自由基水溶液聚合法合成阳离子聚丙烯酰胺P(DMC-AM).正交试验评价得出较佳的工艺条件是:AM/DMC质量配比为4∶3,单体浓度为35％,复合引发剂浓度为0.014％,pH值为4,反应温度为30℃.在上述条件下,产物的特性粘数为8.632dL g-1,阳离子度为20.09％;用红外光谱技术对产物结构进行了表征;在其加入量为8mg L-1的条件下处理硅藻土悬浮液,上层清液透光率接近100％;比较了P(DMC-AM)、无水AlCl3和二者联合处理生活污水的不同絮凝效果,实验表明:P(DMC-AM)的絮凝效果优于无水AlCl3絮凝剂,而二者联合处理的絮凝效果更佳.     

P(DMC-AM)对活性染料废水絮凝脱色效果研究

采用混凝烧杯实验,以脱色率为考察指标,研究了系列化阳离子絮凝剂P(DMC-AM)对活性染料废水的絮凝脱色效果和机理。结果表明:P(DMC-AM)阳离子度越大、特征黏度越高、活性染料分子中所含磺酸基数越多,絮凝脱色效果越好,并具有一定耐酸耐盐性。P(DMC-AM)絮凝脱色机理主要为电中和和吸附架桥。实验证明,P(DMC-AM)对活性染料废水具有良好处理效果。     

P(AM-DM C-MPMS)/PFS絮凝剂的复配及其脱色应用

利用新型絮凝剂聚(丙烯酰胺-甲基丙烯酰氧乙基三甲基氯化铵-甲基丙烯酰氧丙基三甲氧基硅烷)[P(AM-DMC-MPMS)]与聚合硫酸铁(PFS)为原料,制备出复配絮凝剂,并利用复配型絮凝剂对染料和印染废水进行了絮凝研究.结果表明复配絮凝剂P(AM-DMC-MPMs)/PFS是复合相容体系,对染料废水的絮凝效果优于P(AM-DMC)/PFS,对印染废水的最大脱色率为82.57%(剂量55.68 mg/L),优于PFS的脱色效果.     

胺甲基聚丙烯酰胺的合成及其絮凝作用考察

在介绍合成高分子量聚丙烯酰胺(PAM)的同时,对PAM进行胺甲基改性。探讨了聚合温度、时间和二甲胺用量等因素对胺化度的影响。并对其絮凝效果进行考察。结果表明,胺甲基改性的阳离子型聚丙烯酰胺是一种絮凝效果好稳定性高,和沉降速度快的高分子絮凝剂。     

丙烯酰胺在离子液体中的聚合反应研究

以四氟硼酸1-丁基-3-甲基咪唑([bmim]BF4)离子液体为反应溶剂,以过氧化苯甲酰-N,N-二甲基苯胺氧化还原体系为引发剂引发聚合了丙烯酰胺。采用粘度法测定了聚丙烯酰胺的相对粘均分子量,考察了聚合反应时间、反应温度、引发剂浓度对聚合物分子量和聚合反应单体转化率的影响。结果表明,丙烯酰胺可以在[bmim]BF4离子液体中进行氧化还原聚合,聚合物分子量随反应温度的升高而下降,聚合反应速率随着温度的升高而升高,得到的聚丙烯酰胺分子量可高达7.32×107以上,且水溶性良好。     

SiO2/CS-AM-DMC无机-有机絮凝剂固液分离油田废弃钻井液

废弃钻井液的固液分离是钻井行业中的重要过程.作者采用水溶液聚合法,以壳聚糖(CS)为基础、辅以甲基丙烯酰氧乙基三甲基氯化铵(DMC)、丙烯酰胺(AM)、纳米二氧化硅凝胶制备了SiO2/CS-AM-DMC无机-有机絮凝剂.其形貌与结构经SEM、FT-IR表征,粘均分子量用乌式粘度计测定.考察了制备过程中破胶剂的种类,反应...     

Insect antifeedant properties of anthranoids from the genusVismia

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.     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

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.     

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.     

Methyl 2,4,6-decatrienoates Attract Stink Bugs and Tachinid Parasitoids

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.     

2007～2008年世界塑料工业进展

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.     

2005～2006年国外塑料工业进展

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。