PVA/PAA/CMC高吸水树脂的合成和性能研究

以聚乙烯醇(PVA)、丙烯酸(AA)和羧甲基纤维素钠(CMC)为原料,过硫酸钾(KPS)为引发剂,N,N-亚甲基双丙烯酰胺(MBA)为交联剂,采用超声辐射法合成了PVA/PAA/CMC高吸水树脂,利用FTIR对树脂进行了表征。考察了PVA、CMC、MBA、KPS用量和中和度对高吸水树脂吸水倍率的影响,研究了树脂在去离子水、不同盐溶液和pH溶液的吸水速率。实验结果表明:PVA、CMC和AA之间发生了共聚反应,在实验最优合成条件下,制备的高吸水树脂对去离子水和生理盐水的吸水倍率分别为835 g/g和86 g/g。适量引入PVA和CMC可以显著提高树脂的吸水倍率以及改善树脂的耐盐性能,树脂具有较高的吸水速率。     

KHA/PPA缓释控肥料的制备及性能

以丙烯酰胺(AM)、丙烯酸(AA)、腐植酸钾(KHA)、多聚磷酸铵(PPA)为原料,N,N′-二亚甲基双丙烯酰胺(MBA)为交联剂,过硫酸钾(KPS)为引发剂,采用水溶液聚合法合成了具有吸水保水功能的腐植酸多聚磷酸铵缓释控肥料(HA/PPA)。探讨AM与AA质量比、KHA用量、PPA用量、AA中和度、KPS用量、MBA用量对缓释控肥料吸水倍率、保水率、氮素释放率等性能的影响。结果表明,在最佳工艺条件(AM/AA质量比3∶7,腐植酸钾3.0 g,多聚磷酸铵1.0 g,丙烯酸中和度60%,交联剂用量为0.04 g,引发剂用量为0.35 g)下,合成的HA/PPA缓释控肥具有三维网络结构,吸自来水倍率最高可达283 g/g,保水率达90.30%,氮素30 d累积释放73.60%。     

微波辐射下耐盐性高吸水树脂的制备

对微波辐射下丙烯酸(AA)、丙烯酰胺(AM)和凹凸棒的水溶液聚合反应进行研究,合成凹凸棒复合P(AAAM)高吸水树脂,探讨微波功率、辐射时间、单体配比、中和度、引发剂用量、交联剂用量等对高吸水性树脂吸液倍率的影响,并用红外光谱对产物的结构进行表征.合成的高吸水树脂吸水倍率迭1 580 g/g,在质量分数为0.9%的食盐水中的吸液倍率达170 g/g.     

P(AA/AM/APEG)/纳米二氧化硅复合高吸水树脂的合成及性能

以丙烯酸(AA)、丙烯酰胺(AM)、烯丙基聚氧乙烯醚(APEG)为单体,再引入纳米二氧化硅(nano-SiO_2),以过硫酸铵为引发剂,N,N-亚甲基双丙烯酰胺(MBA)为交联剂,采用水溶液聚合法制备了P(AA/AM/APEG)/纳米二氧化硅有机/无机复合高吸水性树脂,考察了交联剂加量、引发剂加量、纳米二氧化硅加量对树脂吸水倍率的影响,并用红外光谱和扫描电镜对产物进行了表征。结果表明:合成最佳条件加入纳米二氧化硅能提高树脂的吸水性能,粒径在80~120目时,复合树脂吸水倍率达到1 865 g/g,P(AA/AM/APEG)树脂吸水倍率为1 681g/g;温度在20~60℃时,复合吸水树脂吸水倍率变化幅度不大;pH在6~8时,其吸水性能最好,吸水倍率为1 865~1 444 g/g;此外,复合树脂具有较好的保水性能,树脂常温下保存15 d,其保水率达到83.2%。红外光谱和扫描电镜分析表明,纳米二氧化硅成功接枝到聚合物上并形成海绵状结构。     

魔芋基半互穿高吸水树脂的制备与吸水性能

以魔芋葡甘聚糖(KGM)、丙烯酸(AA)、丙烯酰胺(AM)和聚乙烯吡咯烷酮(PVP)为原料,过硫酸钾为引发剂,N,N-亚甲基双丙烯酰胺(MBA)为交联剂,采用溶液聚合法制备了KGM-g-AA-AM/PVP半互穿网络高吸水树脂。结果表明,当单体(AA和AM总质量)与KGM质量比为10:1,AM用量为单体总质量的20%,引发剂用量为0.5%,交联剂用量为0.06%,PVP用量为水溶液的2%时,KGM-g-AA-AM/PVP树脂的吸水性能最好,其吸蒸馏水倍率可达1124g·g~(-1),吸生理盐水倍率可达102g·g~(-1)。     

纤维素基高吸水树脂的研究

本研究以羧甲基纤维素(CMC)、丙烯酸(AA)、2-丙烯酰胺基-2-甲基丙磺酸(AMPS)为原料,用过硫酸钾(KPS)为引发剂,N,N'-亚甲基双丙烯酰胺(NMBA)为交联剂,并在丙烯酸聚合液中加入尿素,经接枝共聚制得了既具有吸水、保水能力,又具有肥效性且可缓释的吸水树脂,系统研究了分散时间、聚合温度、交联剂种类和用量、尿素用量等对该高吸水树脂性能的影响。结果表明,高吸水树脂的最佳制备工艺为:分散时间1.5 h,聚合温度75℃,交联剂NMBA用量为单体摩尔数的0.497%,尿素用量为16 g。缓释肥料的缓释性实验结果表明:缓释肥料中的氮具有缓释性。     

高粱秸秆-g-聚丙烯基化合物/坡缕石黏土高吸水树脂制备及动力学研究

以天然高粱秸秆(SS, 颗粒直径>180目)作为纤维素源,N, N?亚甲基双丙烯酰胺(MBA)为交联剂,过硫酸钾(KSB)引发剂,复配坡缕石(PGS)黏土,通过与丙烯酰胺(AM)及部分中和的丙烯酸(AA)接枝共聚制备低成本高吸水树脂SS-g-P(AA/AM)/PGS。运用扫描电镜(SEM)和红外光谱(FTIR)对高吸水树脂的形貌及结构进行了表征,并测试了其吸水性能及热稳定性。结果表明,在坡缕石和高粱秸秆的添加量占反应体系的19.8%时,SS-g-P(AA/AM)/PGS对蒸馏水和自来水的最大吸收量分别为273.0g/g和66.7g/g,且热稳定性较好。通过研究树脂的吸水溶胀过程研了材料的吸水动力学行为,结果表明SS-g-P(AA/AM)/PGS吸自来水和蒸馏水的过程分别符合Fickon扩散模型和non-Fickon扩散模型。     

共聚物高吸水树脂凝胶堵水剂的合成和性能评价

以丙烯酰胺(AM)、丙烯酸(AA)、N,N-亚甲基双丙烯酰胺(MBA)为单体,增强剂为填充料,合成了一种均质的网络结构的吸水树脂凝胶选择性堵水剂。结果表明,高吸水树脂凝胶的最佳配方为:单体配比AM∶AA∶MBA为1∶3∶8(质量比).交联剂用量为0.02%(占单体总质量的比例,下同),引发剂的用量为0.05%,增强剂的用量为5%,pH为9。该吸水树脂在常压下,吸盐水率可以达到140 g/g,吸水率可以达到600.2 g/g,堵水率大于80%,堵油率小于20%。产品具有较好的耐温抗盐性能和较好的选择性堵水能力。     

高粱秸秆-g-聚丙烯基化合物/坡缕石黏土高吸水树脂的制备

以天然高粱秸秆(SS,颗粒直径>180目)作为纤维素源,N,N'-亚甲基双丙烯酰胺(MBA)为交联剂,过硫酸钾(KSB)为引发剂,复配坡缕石(PGS)黏土,通过与丙烯酰胺(AM)及部分中和的丙烯酸(AA)接枝共聚制备低成本高吸水树脂SS-g-P(AA/AM)/PGS。运用扫描电镜(SEM)和红外光谱(FTIR)对高吸水树脂的形貌及结构进行了表征,并测试了其吸水性能及热稳定性。结果表明,在坡缕石黏土和高粱秸秆的添加量占反应体系总质量的19.51%时,SS-g-P(AA/AM)/PGS对蒸馏水、自来水、黄河水的最大吸收量分别为273.0、66.7、60.4 g/g,且热稳定性较好。通过研究树脂的吸水溶胀过程确定了材料的吸水动力学行为,结果表明,SS-g-P(AA/AM)/PGS吸自来水和蒸馏水的过程分别符合Fickon扩散模型和non-Fickon扩散模型。     

柚皮粉接枝P(AA-AM)树脂的制备及其尿素吸放性能

采用水溶液聚合法,以农林废弃物柚皮粉(PP)为原料,与丙烯酸(AA)、丙烯酰胺(AM)接枝共聚,制备了低成本高吸水树脂(PP-SA),并探讨了其形成机理。利用FTIR和TG对PP-SA的结构及热稳定性进行了表征,结果表明:PP与AA、AM之间发生了接枝共聚反应;PP-SA升温至700℃失重率仅约为60%,而纯聚丙烯酸-聚丙烯酰胺共聚物〔P(AA-AM)〕为79%。考察了PP-SA在不同质量浓度的尿素溶液中的吸液倍率、尿素负载量及尿素释放率,结果显示:PP-SA对6 g/L的尿素溶液有最大的吸收倍率(362 g/g);在10 g/L的尿素溶液中溶胀干燥后的PP-SA的尿素负载量达到最大值66.7%,其在蒸馏水中的尿素释放率可达74%。     

Many Drugs of Abuse May Be Acutely Transformed to Dopamine,Norepinephrine and Epinephrine In Vivo

It is well established that a wide range of drugs of abuse acutely boost the signaling of the sympathetic nervous system and the hypothalamic–pituitary–adrenal (HPA) axis, where norepinephrine and epinephrine are major output molecules. This stimulatory effect is accompanied by such symptoms as elevated heart rate and blood pressure, more rapid breathing, increased body temperature and sweating, and pupillary dilation, as well as the intoxicating or euphoric subjective properties of the drug. While many drugs of abuse are thought to achieve their intoxicating effects by modulating the monoaminergic neurotransmitter systems (i.e., serotonin, norepinephrine, dopamine) by binding to these receptors or otherwise affecting their synaptic signaling, this paper puts forth the hypothesis that many of these drugs are actually acutely converted to catecholamines (dopamine, norepinephrine, epinephrine) in vivo, in addition to transformation to their known metabolites. In this manner, a range of stimulants, opioids, and psychedelics (as well as alcohol) may partially achieve their intoxicating properties, as well as side effects, due to this putative transformation to catecholamines. If this hypothesis is correct, it would alter our understanding of the basic biosynthetic pathways for generating these important signaling molecules, while also modifying our view of the neural substrates underlying substance abuse and dependence, including psychological stress-induced relapse. Importantly, there is a direct way to test the overarching hypothesis: administer (either centrally or peripherally) stable isotope versions of these drugs to model organisms such as rodents (or even to humans) and then use liquid chromatography-mass spectrometry to determine if the labeled drug is converted to labeled catecholamines in brain, blood plasma, or urine samples.     

Sapindaceae,cyanolipids, and bugs

Scentless plant bugs (Heteroptera: Rhopalidae) are so named because adults of the Serinethinae have vestigial metathoracic scent glands. Serinethines are seed predators of Sapindales, especially Sapindaceae that produce toxic cyanolipids. In two serinethine species whose ranges extend into the southern United States,Jadera haematoloma andJ. sanguinolenta, sequestration of host cyanolipids as glucosides renders these gregarious, aposematic insects unpalatable to a variety of predators. The blood glucoside profile and cyanogenesis ofJadera varies depending on the cyanolipid chemistry of hosts, and adults and larvae fed golden rain tree seeds (Koelreuteria paniculata) excrete the volatile lactone, 4-methyl-2(5H)-furanone, to which they are attracted.Jadera fed balloon vine seeds (Cardiospermum spp.) do not excrete the attractive lactone. Loss of the usual heteropteran defensive glands in serinethines may have coevolved with host specificity on toxic plants, and the orientation ofJadera to a volatile excretory product could be an adaptive response to save time.Mention of a commercial product does not consititute an endorsement by the USDA.     

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.     

2008～2009年世界塑料工业进展

收集了2008年7月～2009年6月世界塑料工业的相关资料,介绍了2008～2009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、环氧树脂、不饱和聚酯树脂)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。     

ICP-MS法测定地球化学样品中As、Cr、Ge、V等18种微量痕量元素的研究

建立了测定地球化学样品中包括As、Cr、Ge、V等18种微量、痕量元素的ICP-MS方法。地化试样用HF-HNO3混酸分解后,以1 1 HNO3溶解干渣。由于制样不使用盐酸,避免了Cl对As、Cr、Ge、V的质谱干扰。用国家一级地球化学标准物质GBW 07309制备溶液优化仪器工作参数,并用于校准。方法测定限(6s)为:0.007~6.4μg/g,精密度(RSD%,n=12)为:29%~9.4%,经过国家一级地球化学标准物质的分析验证,结果与标准值吻合。方法已应用于国土资源调查的试样分析。