壳聚糖季铵盐复合絮凝剂对高岭土悬浮液的絮凝处理

以3-氯-2-羟丙基三甲基氯化铵(CTA)对壳聚糖(CTS)进行季铵化改性,制备了壳聚糖季铵盐(CTA-CTS),用其和聚合氯化铝(PAC)复配对高岭土悬浮液进行絮凝处理.考察了复合絮凝剂的质量配比、沉降时间、pH值对絮凝性能的影响.最佳絮凝条件为:壳聚糖季铵盐用量为2 mg/L、m(PAC):m(CTA-CTS)=1...     

高取代度醚化淀粉的湿法制备及其絮凝性能研究

以玉米淀粉(St)为原料、2,3-环氧丙基三甲基氯化铵(GTA)为醚化剂,利用湿法合成高取代度的阳离子醚化淀粉絮凝剂St-GTA。通过正交实验对St-GTA的合成条件进行筛选,结果表明,最佳合成条件为:n(CTA)∶n(St)=1. 2∶1、m(NaOH)∶m(St)=0. 08∶1、反应温度为70℃、反应时间为3 h。在该条件下合成的产物取代度可达0. 717 3。以高岭土悬浊液为模拟污水,考察了絮凝剂投加量、絮凝体系pH、絮凝温度、絮凝时间对絮凝效果的影响。结果表明,对于质量分数为2%的高岭土悬浊液,当pH=7、絮凝温度为25℃、絮凝时间为0. 5 h时,St-GTA的最佳质量浓度为8 mg/L,透光率可达92. 81%。     

阳离子淀粉在水处理上的絮凝研究

以玉米淀粉为原料、3-氯-2-羟丙基三甲基氯化铵(CTA)为阳离子化试剂,采用半干法工艺制备了不同取代度阳离子淀粉,并将其用于实验室配制的高岭土水样的絮凝实验,探讨了阳离子淀粉取代度及用量、pH值、絮凝时间、絮凝温度对絮凝效果的影响,并分析了絮凝机理。结果表明,阳离子淀粉对高岭土类水样具有很好的絮凝效果,可显著降低水样的浊度。     

壳聚糖季铵盐对高岭土悬浮液的絮凝处理

介绍了以3-氯-2-羟丙基三甲基氯化铵(CTA)为改性剂接枝改性壳聚糖,制备了2-羟丙基三甲基壳聚糖季铵盐。用其处理高岭土的悬浮液,讨论了沉降时间、壳聚糖季铵盐的用量、pH值对高岭土悬浮液絮凝效果的影响。结果表明,当沉降18 min,壳聚糖季铵盐添加量为8 mg/L,pH=4时,絮凝效果最好,污水的浊度值可降至1.2。     

淀粉-聚丙烯酰胺接枝共聚物的工艺优化与性能研究

通过玉米淀粉接枝聚丙烯酰胺(PAM)制成了新型复合絮凝剂S-g-PAM,进行了影响接枝共聚物合成的单因素实验和正交实验,以对高岭土悬浊液的絮凝性能为评价指标。结果表明,最佳合成条件为,m(玉米淀粉)∶m(PAM)=3∶0.001(质量比),NaOH∶NaOCl=2∶3(体积比),反应时间40 min,反应温度30℃,对高岭土溶液(110NTU)最佳去浊度效果为97%,投加量为30 mg/L。S-g-PAM使用的pH值范围为8~10,最佳温度范围20~40℃,与其它絮凝剂相比,其絮凝效果较好。     

聚合硅酸硫酸铝

研究了聚合硅酸硫酸铝对高岭土悬浮液的絮凝性能。结果表明，聚合硅酸硫酸铝对高岭土悬浮液具有极好的絮凝作用，其絮凝效果与聚合硅酸硫酸铝的碱化度，加入量和高岭土悬浮液的pH值有关；絮凝机理主要为吸附架桥与卷扫等作用。     

阳离子淀粉絮凝剂St-g-PDMC-GTA的合成及其絮凝性能

针对常用絮凝剂金属离子和有毒有机单体残留等问题,通过淀粉(st)与甲基丙烯酰氧乙基三甲基氯化铵(DMC)合成St-g-PDMC,再与3-氯-羟丙基三甲基氯化铵(CTA)醚化反应接枝共聚合成阳离子淀粉絮凝剂St-g-PDMC-GTA。考察了催化剂用量、单体比例、反应温度和反应时间对产物氮含量的影响。结果表明,当m(St-g-PDMC):m(CTA)=1:1.4,催化剂NaOH用量为反应物固含量的8%,反应温度70℃,反应时间4h时,St-g-PDMC-GTA的氮含量最高为4.17%,特性黏度为0.1581 dL·g~(-1)。采用高岭土悬浊液为模拟污水,对St-g-PDMC、St-g-PDMC-GTA和市售阳离子聚丙烯酰胺(CPAM)进行絮凝实验,考察了絮凝剂投加量、絮凝体系pH值、絮凝温度和絮凝时间对透光率的影响。结果表明,St-g-PDMC-GTA的适宜投加量为5～8 mg·L~(-1),pH为2～8,絮凝时间30 min后模拟液的透光率大于90%。     

含硼聚硅酸铁锌絮凝剂的制备及其性能研究

以硅酸钠、硫酸铁、硫酸锌和硼砂为原料制备含硼聚硅酸铁锌絮凝剂(PSZBFS),以高岭土模拟水样为目标物,考察了其絮凝性能,通过正交试验优化了制备工艺条件,用红外光谱和XRD对其结构进行了表征。结果表明,硅酸聚合p H=4,聚合时间为80 min,c(Si O2)=0.6 mol/L,n(Fe)∶n(Si)=1.0∶1,n(Zn)∶n(Si)=1.5∶1,n(B)∶n(Si)=0.05∶1,得到的PSZBFS絮凝效果最好。模拟水样p H为8,投加量为5 mmol/L时絮凝效果最佳,经过Zeta电位分析,用PSZBFS处理高岭土模拟水样,电中和能力和吸附架桥能力强。     

阳离子淀粉絮凝剂合成及处理煤矿井废水性能研究

针对高浊度煤矿井水的特点,以玉米淀粉(St)和丙烯酰胺(AM)为原料,过硫酸铵和亚硫酸氢钠为引发剂,通过共聚反应合成了淀粉/丙烯酰胺接枝共聚物絮凝剂,以2,3-环氧丙基三甲基氯化铵(GTA)为阳离子醚化剂,对淀粉接枝共聚物进行阳离子化。根据正交试验确定了最佳合成工艺条件:接枝共聚反应时间为4 h,St用量为5 g,AM与St质量比为4∶1,引发剂用量为1.4 g,GTA用量为2.6 g,NaOH用量为0.24 g,醚化反应时间为2.5 h,反应温度为70℃。并将阳离子淀粉絮凝剂复配PAC与现有絮凝工艺进行了对比和性能评价,分别对投加量、复配效果以及适合的温度、pH值对絮凝性能参数进行了评价,从而得出阳离子淀粉絮凝剂优化的应用条件。     

反相乳液聚合法制备HACC及其絮凝性能

以壳聚糖(CTS)和2,3-环氧丙基三甲基氯化铵(GTA)为原料,用反相乳液聚合法合成了壳聚糖季铵盐(HACC)。并采用FTIR、1HNMR、ESEM和XRD对其结构和形貌进行了表征。考察了反相乳液体系中复合乳化剂的HLB值、V(油)∶V(水)、引发剂用量、时间、温度和m(GTA)∶m(CTS)对反应取代度及产率的影响。结果表明:合成HACC的最佳工艺条件为:复合乳化剂的HLB=6.0、V(油)∶V(水)=1.0∶1、w(引发剂)(占单体质量的百分数)=1.5%,反应时间为5 h,温度为60℃,m(GTA)∶m(CTS)=3.0∶1。在此条件下,产物的取代度和产率均达最大值,分别为1.331和81.16%。用原料CTS、自制HACC和市售絮凝剂阳离子聚丙烯酰胺(CPAM)对高岭土模拟废水进行了絮凝实验。考察了絮凝体系p H、絮凝剂投加量对絮凝效果的影响。结果表明:CPAM、CTS和HACC对高岭土模拟废水都具有絮凝效果,HACC适宜的絮凝p H为6,絮凝剂的最佳投加量为1 mg/L。在此条件下,HACC、CTA、CPAM处理模拟废水的剩余浊度分别为3.98、10.81、25.67 NTU。     

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。