两性高分子絮凝剂的合成与应用研究

在氧化还原体系过硫酸铵/亚硫酸氢钠作引发剂条件下,丙烯酰胺(AM)、二甲基二烯丙基氯化铵(DMDAAC)、丙烯酸(AA)经水溶液共聚合成两性高分子絮凝剂PDAA。探讨了单体浓度、反应温度、引发剂用量等因素对聚合反应速率和产物特性黏数的影响。并以硅藻土模拟废水对制得的产品进行了絮凝实验。实验结果表明:合成两性高分子絮凝剂PDAA的较佳条件为:单体质量分数为35%,引发剂用量占单体质量分数为0.1%,反应温度为30℃。     

低分子质量非离子型聚丙烯酰胺合成工艺探讨

以丙烯酰胺为聚合单体,（NH4）2S2O4／NaHSO3体系为引发剂,采用水溶液自由基聚合制备了低分子质量非离子型聚丙烯酰胺,对其合成工艺进行了探讨。单因素实验得出合成最佳条件为：温度30℃,时间3h,引发剂用量0．1％,单体质量分数15％;再在单因素结论的基础上作正交实验。得出了对实验影响由大到小的因素分别为温度、单体浓度、引发剂的用量和反应时间,且得到了实验最佳合成条件为温度30℃,时间2．5h,引发剂用量0．1％,单体质量分数15％。     

低磷膦磺酸阻垢分散剂ZHCD-05的合成研究

以水为溶剂,丙烯酸(AA)、马来酸酐(MAn)、烯丙基磺酸钠(SAS)和次磷酸钠为单体,过硫酸铵为引发剂,合成了一种集膦酰基、羧基和磺酸基于一体,低磷含量,综合性能良好的膦磺酸阻垢分散剂ZHCD-05.考察了产品综合性能与单体配比、引发剂用量、反应温度及反应时间的关系,得出了合成此共聚物的最佳工艺条件:m(MAn)∶m(AA)∶m(SAS)=1∶0.2∶0.5,NaH2PO2质量分数为8%,过硫酸铵质量分数为5.5%,反应温度为80～85℃,反应时间4 h.     

IA/AA/AMPS三元共聚物的合成及阻垢性能研究

以水作溶剂,过硫酸铵为引发剂,衣康酸(IA)、丙烯酸(AA)、2-丙烯酰胺-2-甲基丙磺酸(AMPS)为单体,合成了IA/AA /AMPS三元共聚物.探讨了引发剂用量、链转移剂用量、反应温度等对共聚物阻垢性能的影响.结果表明,引发剂用量为单体总质量的4.5%,链转移剂用量为单体总质量的9.5%,反应温度为95℃时,共聚...     

改性腐植酸盐-丙烯酰胺-丙烯酸复合吸水树脂制备及性能研究

以改性腐植酸盐、丙烯酰胺、丙烯酸为原料,采用水溶液聚合法制备了复合高吸水性树脂PAAH,考察了交联剂用量、引发剂用量、单体配比和反应温度对产品性能的影响,得到了最佳反应条件：交联剂和引发剂分别占单体总质量分数的0．6％和110．9％;     

丙烯酸酯共聚乳液水性涂料增稠剂的研制

以丙烯酸乙酯和甲基丙烯酸为原料,采用种子聚合方法制备了平均分子量为12000~15000的25%丙烯酸酯共聚乳液。产品的性能受乳化剂用量、引发剂用量、反应温度和反应时间的影响明显,最佳的反应条件为乳化剂用量4.5%(单体计质量分数),引发剂用量0.2%(以混合单体质量分数计)、种子聚合温度(45±2)℃,核壳聚合反应温度(80±2)℃,反应时间为3h为最佳。产品用于水性涂料增稠剂效果良好,储存稳定性超过同类产品。     

高固体分羟基丙烯酸酯树脂的研制

采用溶液聚合,引发剂和单体采用混合均匀滴加的方式,合成高固体分羟基丙烯酸酯树脂。研究了引发剂的种类及用量对合成树脂性能的影响。实验发现,采用二叔戊基过氧化物(DTAP)作为引发剂,用量为3.5%时,合成的树脂分子质量小、分子质量分布窄,黏度也小。反应温度140℃,链转移剂巯基乙醇用量为2.5%,用m/m=4:1为混合溶剂,合成树脂性能较好。二甲苯乙酸丁酯     

两性型高分子絮凝脱色剂PAM/AMPS/DMDAAC的合成与表征

以非离子单体丙烯酰胺(AM)、阴离子单体2-丙烯酰胺基-2-甲基丙磺酸(AMPS)和阳离子单体二甲基二烯丙基氯化铵(DMDAAC)为原料,以过硫酸铵、亚硫酸钠、2,2'-偶氮二异丁基脒二盐酸盐为引发荆,合成了絮凝剂产品PAM/AMPS/DMDAAC.在单体质量分数为10%的条件下,得到了最佳的合成工艺为:m(AM):m(DMDAAC):m(AMPS)=7:2:1,反应温度为45℃,偶氮引发剂2,2'-偶氮二异丁基脒二盐酸盐用量为溶液质量分数的0.006%,过硫酸铵用量为溶液质量分数的0.004%,哑硫酸氢钠用量为溶液质量分数的0.002%;对PAM/AMPS/DMDAAC的结构进行红外光谱和透射电镜表征,表明PAM/AMPS/DMDAAC链节上含有季铵盐和磺酸盐基团,分子呈现长链结构,分子链刚性好,交联现象少.     

正交实验优化低分子质量聚丙烯酸钠合成工艺

采用水溶液聚合法,以丙烯酸为单体,过硫酸铵-亚硫酸氢钠为氧化还原引发体系,亚硫酸氢钠为链转移剂制得分子质量为3000～4000的聚丙烯酸钠。采用粘度法测得产物的黏均分子质量,对丙烯酸单体和聚丙烯酸钠聚合物的FTIR图谱进行了分析,通过正交实验研究了各因素对聚丙烯酸钠分子质量的影响趋势和程度。结果表明:影响最显著的因素为单体浓度,其次为反应温度,再次为引发剂用量,反应时间的影响最小。确定了最佳合成工艺条件:反应温度为45℃,反应时间为4h;丙烯酸单体质量分数为25%,引发剂过硫酸铵用量为单体质量的6%,链转移剂亚硫酸氢钠用量为单体质量的3%。FTIR谱图中不含碳碳双键,且有羧酸盐的特征峰出现,验证了聚合物的合成。该工艺节省能源,且制备方法简单,易于工业化生产。     

马来酸酐-丙烯酸共聚物的合成及性能研究

以丙烯酸(AA)和马来酸酐(MA)为单体,过硫酸铵和亚硫酸氢钠为引发剂,采用水溶液聚合法,合成了一种无磷助洗剂丙烯酸和马来酸酐共聚物。研究了单体配比、引发剂用量、聚合反应温度对助洗性能的影响。确定了最佳产品的合成条件:单体中MA∶AA=1∶3(质量比),引发剂与单体质量比为4%,氧化剂∶还原剂=2∶1(质量比),反应温度为90℃,反应时间1.5h。研究了此条件下合成的聚合物与阴离子表面活性剂间的相互作用。     

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。