一种温敏性酸液稠化剂的合成及性能

将丙烯酰胺(AM)、甲基丙烯酰氧乙基三甲基氯化铵(DMC)及带长链温敏基团的烯丙基聚氧乙烯醚(APEG)进行自由基共聚,制备出一种新型温敏性酸液稠化剂P(AM-DMC-APEG),并得到最佳合成条件:单体质量分数40%,单体摩尔比n(APEG)∶n(AM)∶n(DMC)=1∶20∶2,w(引发剂)=0.08%,聚合温度70℃,聚合时间3.5 h。采用红外光谱和静态光散射对P(AM-DMC-APEG)的结构与相对分子质量进行了表征;并对稠化剂的温敏性能和缓速性能作出评价。结果表明,该研究所合成的稠化剂P(AM-DMC-APEG)的温敏性能稳定,并具有良好的缓速效果。     

一种温敏性酸液稠化剂的合成及性能研究

将丙烯酰胺（AM）、甲基丙烯酰氧乙基三甲基氯化铵（DMC）及带长链温敏基团的烯丙基聚氧乙烯醚（APEG）进行自由基共聚,制备出一种新型温敏性酸液稠化剂P(AM-DMC-APEG),并得到最佳合成条件：单体浓度40%,单体配比1:20：2（APEG：AM：DMC）,引发剂浓度0.08%,聚合温度70℃,聚合时间3.5h。采用红外光谱和静态光散射对P(AM-DMC-APEG)的分子结构与分子量进行表征;并对稠化剂的温敏性能和缓速性能作出评价。结果表明,本研究所合成的稠化剂P（AM-DMC-APEG）的温敏性能稳定,并具有良好的缓速效果。     

耐245℃超高温压裂液稠化剂的制备与性能分析

采用主链基团AM、强水解基团AA、杂原子耐温型基团AMPS、梯型聚合物单体NVP和大位阻基团DMAM,通过水溶液聚合,合成了耐温245℃以上的新型AM/DMAM/AMPS/AA/NVP五元聚合物压裂液稠化剂,考察了单体浓度、聚合pH、引发剂用量和聚合温度对反应后胶块性质的影响,通过高温流变仪分析其耐温耐剪切性质。结果表明,优化的AM/DMAM/AMPS/AA/NVP五元聚合物稠化剂合成条件为:聚合单体水溶液浓度为30%,聚合pH为8,引发剂(NH_4)_2S_2O_8和NaHSO_4比例为1∶1,引发剂占单体总质量为0.2%,聚合温度为10～20℃,反应时间8 h。五元聚合物适合作为耐245℃超高温压裂液体系的稠化剂使用。     

聚氧乙烯基型降滤失剂SJ-1的合成与性能评价

采用2-丙烯酰胺基-2-甲基丙磺酸(AMPS)、丙烯酰胺(AM)与具有大分子侧链聚氧乙烯基(C2H4O)n的烯丙基聚氧乙烯醚(APEG)三元共聚得到钻井液用降滤失剂SJ-1,并对其进行了性能评价。通过单因素实验优化得到最佳合成方案为:单体质量分数为15%,反应温度控制在60℃,引发剂质量分数为0.2%,n(AM)∶n(AMPS)∶n(APEG)=14∶5∶1。通过红外光谱表征可知,所合成的聚合物结构和预计的结构一致。性能评价表明,所合成的聚合物具有较好的抗温能力(200℃),在盐质量分数为30%的盐水泥浆中仍具有较好的降失水能力。     

四元共聚钻井液降滤失剂的合成与性能评价

采用丙烯酰胺(AM)、烯丙基磺酸钠(SAS)、对苯乙烯磺酸钠(SSS)与烯丙醇聚氧乙烯醚(APEG)制备了一种抗温耐盐AM-SAS-SSS-APEG四元共聚物用于钻井液降滤失剂。通过单因素法考察了单体配比、单体浓度、引发剂用量、反应温度等对合成降滤失剂性能的影响,确定了最佳合成条件为:单体质量比:m(AM)∶m(APEG)∶m(SSS)∶m(SAS)=6.5∶2.0∶0.5∶1.0,单体质量分数为20%,引发剂用量为单体总质量的0.2%,反应温度60℃。对该条件下制备的聚合物进行了红外光谱表征(FTIR);热重分析(TGA)表明,该聚合物具有较好的热稳定性;对不同条件下泥浆形成的滤饼进行了电镜扫描(SEM),对比滤饼形貌发现,加入降滤失剂后可形成薄而致密的泥饼。抗温耐盐实验结果表明,所合成的聚合物抗温能力较好(190℃),在盐水及复合盐水钻井液中均具有较好的降失水能力。     

一种抗温抗盐稠化剂的研究

以AM(丙烯酰胺)、AMPS(2-丙烯酰胺基-2-甲基丙磺酸)和NVP(N-乙烯基吡咯烷酮)为单体,APS(过硫酸铵)/亚硫酸氢钠为氧化还原型引发剂,采用水溶液聚合法合成了一种三元聚合物基稠化剂。着重探讨了反应单体配比、单体浓度、引发剂掺量、反应温度和反应时间等对产物性能的影响。研究结果表明:该三元聚合物具有良好的增稠性、耐热性和耐盐性,其最佳合成条件是m(AM)∶m(AMPS)∶m(NVP)=7.3∶2.0∶0.7、单体浓度为30%、w(氧化还原型引发剂)=0.2%(相对于单体总质量而言)、反应温度为45℃、反应时间为4 h、m(APS)∶m(亚硫酸氢钠)=1∶1和体系pH=7。     

一种疏水缔合型压裂液稠化剂的室内研究

以丙烯酰胺、丙烯酸等为原料,用水溶液聚合法合成了一种压裂液用稠化剂(PAAM-16)并在室内研究了其性质。合成优化条件为:聚合温度60℃、聚合时间4 h、单体浓度20%、引发剂加量0.3%、p H=8以及单体配比(摩尔比)丙烯酰胺(AM)∶丙烯酸(AA)∶十六烷基烯丙基二甲基氯化铵(MJ-16)=84∶15∶1。对质量分数为0.8%的聚合物溶液性能评价结果表明,该稠化剂是一种典型的非牛顿流体,随着温度的上升,表观粘度逐渐下降,到90℃下仍能达到90 m Pa·s。在170 s-1下剪切3 h后,其粘度仍能达到153 m Pa·s;随着盐浓度的升高,聚合物的表观粘度先增大到180 m Pa·s,再缓慢降低至138 m Pa·s,表现出较强的抗盐性。     

一种疏水缔合型压裂液稠化剂的室内研究

以丙烯酰胺、丙烯酸等为原料,用水溶液聚合法合成了一种压裂液用稠化剂(PAAM-16)并在室内研究了其性质。合成优化条件为:聚合温度60℃、聚合时间4 h、单体浓度20%、引发剂加量0.3%、p H=8以及单体配比(摩尔比)丙烯酰胺(AM)∶丙烯酸(AA)∶十六烷基烯丙基二甲基氯化铵(MJ-16)=84∶15∶1。对质量分数为0.8%的聚合物溶液性能评价结果表明,该稠化剂是一种典型的非牛顿流体,随着温度的上升,表观粘度逐渐下降,到90℃下仍能达到90 m Pa·s。在170 s-1下剪切3 h后,其粘度仍能达到153 m Pa·s;随着盐浓度的升高,聚合物的表观粘度先增大到180 m Pa·s,再缓慢降低至138 m Pa·s,表现出较强的抗盐性。     

疏水缔合压裂液用稠化剂HAP-1的制备及性能评价

以功能疏水单体N-十二烷基丙烯酰胺(N-DAM)、2-丙烯酰胺基-2-甲基丙磺酸(AMPS)、丙烯酰胺(AM)和丙烯酸(AA)为原料,采用水溶液法制得疏水缔合压裂液用稠化剂(HAP-1),考察了合成过程中不同因素对HAP-1性能的影响,确定了HAP-1的最佳合成工艺:反应时间为4 h,反应温度为70℃,单体总质量分数为25%,引发剂质量分数为0.03%(相对于单体总质量),反应体系p H为8,单体摩尔比n(AM)∶n(AA)∶n(AMPS)∶n(N-DAM)=80∶15∶4∶1。性能评价结果表明,HAP-1压裂液具有良好的耐温性能、抗剪切性能、悬砂性能和破胶性能,且破胶液残渣质量浓度低于常规压裂液破胶液,适于90℃以下油气储层压裂改造。     

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。     

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.     

Novel polyurethane coating technology through glycidyl carbamate chemistry

Glycidyl carbamate chemistry combines the excellent properties of polyurethanes with the crosslinking chemistry of epoxy resins. Glycidyl carbamate functional oligomers were synthesized by the reaction of polyfunctional isocyanate oligomers and glycidol. The oligomers were formulated into coatings with several amine functional crosslinkers at varying stoichiometric ratios and cured at different temperatures. Properties such as solvent resistance, hardness, and impact resistance were dependent on the composition and cure conditions. Most coatings had an excellent combination of properties. Studies were carried out to determine the kinetics of the curing reaction of the glycidyl carbamate functional oligomers with multifunctional and model amines. Detailed kinetic analysis of the curing reactions was also undertaken. The results indicated that the glycidyl carbamate functional group is more reactive than a glycidyl ether group. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, on October 27–29, 2004, in Chicago, IL.     

Highly moisture-proof polysilsesquioxane coating prepared via facile sol-gel process

A highly moisture-proof polysilsesquioxane coating was obtained from a new bis-silylated precursor, which was synthesized from 3-aminopropyltriethoxysilane (APTES) and m-xylylene diisocyanate (m-XDI) in tetrahydrofuran (THF) and verified by ¹H MAS NMR. For direct comparison purposes, an SiO₂ coating was also prepared by the Stöber method using tetraethoxysilane (TEOS) as the reactant. Interestingly, the coating obtained from the polysilsesquioxane sol exhibited a much higher moisture resistance capability than its counterpart, which was attributed to its more compact feature between nanoparticles as characterized by N₂ absorption experiment and transmission electron microscopy (TEM). Furthermore, its high transparency of about 92% showed potential for application in the protection of optical crystals.