有机硼交联剂的合成及性能研究

以硼砂为原料,在氢氧化钠催化作用下与葡萄糖酸钠进行络合反应,制备了压裂液用有机硼交联剂,对反应物用量和反应条件进行研究。结果表明,性能较好的有机硼交联剂的合成条件为:硼砂15%,配位体葡萄糖酸钠30%,溶剂(丙三醇与水质量比1∶4)55%,反应温度为80℃,合成反应5 h。压裂液的滤失性和破胶性室内评价结果表明,破胶彻底,残渣少,滤失低,对储层伤害小,可以满足油田压裂液对交联剂的需求。     

新型有机胺硼交联剂AB-1的合成及应用

以硼酸、正丁醇、乙二醇和四乙烯五胺为原料制备出一种针对多羟基醇压裂液体系的新型有机胺硼交联剂AB-1,确定了交联剂的最佳合成工艺,并考察了制备有机胺硼交联剂的影响因素。研究结果表明：第一步酯化反应,硼砂质量分数15%,乙二醇35%,正丁醇25%,在120℃下反应1h;第二步络合反应,四乙烯五胺10%,季戊四醇5%,氢氧化钠5~10%,在150℃下、反应时间2h,得到交联剂AB-1。压裂液性能评价结果表明：交联剂AB-1与羟丙基胍胶CJ2-6交联产生的冻胶具有良好的延缓交联性能、耐温抗剪切性能、悬砂性能和破胶性能。     

有机胺硼交联剂AB-1的合成及应用

以硼酸、正丁醇、乙二醇和四乙烯五胺为原料制备出一种针对多羟基醇压裂液体系的有机胺硼交联剂AB-1,考察了制备有机胺硼交联剂的影响因素,确定了交联剂的最佳合成工艺。结果表明:第一步酯化反应,硼酸加量为15 g,乙二醇35 g,正丁醇25 g,在120℃下反应1 h;第二步络合反应,四乙烯五胺加量为10 g,季戊四醇5 g,氢氧化钠5~10 g,在150℃下反应2 h,得到交联剂AB-1。压裂液性能评价结果表明:交联剂AB-1与羟丙基胍胶CJ2-6交联产生的冻胶具有良好的延缓交联性能、耐温抗剪切性能、悬砂性能和破胶性能。     

新型压裂液用有机硼交联剂的合成、表征与性能评价

通过实验研究合成了有机硼交联剂ABE-30,并通过核磁氢谱、核磁硼谱与红外光谱等手段对ABE-30进行分析表征,推测出产物具有簇状配位的化学结构。研究了ABE-30交联剂与胍胶溶液的交联性能,并对交联体系的耐温耐剪切性能进行了研究。结果表明,与常规硼酸钠交联剂相比,合成交联剂ABE-30能与低浓度胍胶有效交联,交联体系具有良好的热稳定性与耐剪切性能,具有良好的应用前景。     

新型压裂液用有机硼交联剂的合成、表征与性能评价

通过实验研究合成了有机硼交联剂ABE-30,并通过核磁氢谱、核磁硼谱与红外光谱等手段对ABE-30进行分析表征,推测出产物具有簇状配位的化学结构。研究了ABE-30交联剂与胍胶溶液的交联性能,并对交联体系的耐温耐剪切性能进行了研究。结果表明,与常规硼酸钠交联剂相比,合成交联剂ABE-30能与低浓度胍胶有效交联,交联体系具有良好的热稳定性与耐剪切性能,具有良好的应用前景。     

多氨基硼交联剂的制备与性能评价

以多胺化合物和硼酸酯为原料,合成羟丙基胍胶压裂液用有机硼交联剂,通过在交联剂中引入多个含硼交联位点,达到降低压裂液体系中羟丙基胍胶的用量、提升压裂液体系耐温性能的目的。采用FTIR、1HNMR和11BNMR对不同交联剂的结构进行了表征,并分析了反应机理。考察了多胺化合物的种类(二乙烯三胺、四乙烯五胺、多乙烯多胺、聚乙烯亚胺-600)、反应物的配比、反应温度和反应时间对产物交联性能的影响,结果表明,当硼酸酯与多乙烯多胺的质量比为3∶2、反应时间为4h、反应温度为150℃时,可以制备性能最优的交联剂BNX-1。评价了BNX-1配制压裂液的耐温耐剪切性能、破胶性能和静态滤失性能。结果表明,以羟丙基胍胶质量分数0.35%、羟丙基胍胶溶液与BNX-1交联质量比100∶0.4配制的压裂液体系,在140℃、170s–1下剪切,120 min后黏度为122 mPa·s;以工业交联剂TCB-1作为对照(以羟丙基胍胶质量分数为0.5%、羟丙基胍胶溶液与TCB-1交联质量比为100∶0.5配制的压裂液体系),在同等条件下剪切,黏度为98 mPa·s。     

新型有机硼交联剂的合成及性能评价

针对交联剂在井深1500³000米的井下压裂施工的使用,通过室内实验合成了适用于此类油田的有机硼交联剂,其最佳合成工艺为:硼砂15%,催化剂4%;反应温度80℃,反应时间4h。该有机硼交联剂适用于超低浓度羟丙基瓜尔胶体系(0.253000米的井下压裂施工的使用,通过室内实验合成了适用于此类油田的有机硼交联剂,其最佳合成工艺为:硼砂15%,催化剂4%;反应温度80℃,反应时间4h。该有机硼交联剂适用于超低浓度羟丙基瓜尔胶体系(0.25⁰.38%),压裂液具有较好的耐温性能(135℃)、延迟交联性能(125s)和抗剪切性(200mPa·s),适用于超低渗透油气田应用。     

有机锆对羧甲基羟丙基瓜胶的交联性能研究

以氧氯化锆和柠檬酸等为原料,合成了适用于羧甲基羟丙基瓜胶在酸性条件下交联的有机锆交联剂,考察了pH值、温度、羧甲基羟丙基瓜胶和交联剂加量等对体系成胶时间的影响,评价了形成冻胶的抗温抗剪切性能、滤失性能和破胶性能.实验发现,在pH值为3.0时,羧甲基羟丙基瓜胶/有机锆体系具有可控的延缓交联特性,质量分数为0.5%和0.6...     

低浓度胍胶压裂液有机硼交联剂YJ-P的合成与应用

该文通过考察压裂液的悬砂时间确定了合成反应中硼砂用量、配位剂组分质量比、溶剂组分质量比对有机硼交联剂YJ-P交联低浓度胍胶压裂液携砂性能的影响,并通过动态流变研究压裂体系的黏弹性。结果表明,硼砂质量分数25%(即硼砂质量占交联剂质量的百分数,下同),配位剂m(葡萄糖):m(乙二醇)=1:1.5,溶剂m(丙三醇):m(水)=6:1,交联剂质量分数为1.2%(即交联剂质量占压裂液质量的百分数,下同)时,悬砂性能最优,悬砂时间达到了27 min/mm。确定反应时间4.0 h,反应温度80℃,改性有机硼交联剂对低浓度胍胶压裂液有良好的悬砂性。当胍胶的质量分数达0.2%时,剪切频率增加,动态模量增加,在角频率达10 rad/s时,G'>G″,且G'>0.1 Pa,压裂液有较好的黏弹性。     

耐温缓交联有机锆冻胶压裂液的制备与性能评价

针对目前现场常用的压裂液耐温性差、交联时间短及残渣含量高等诸多问题，以氧氯化锆、多元醇、有机配体、络合交联剂和高温稳定剂等原料成功合成了有机锆交联剂YJ-3，并选用聚丙烯酰胺类稠化剂RG-1和添加剂制备出一种耐温缓交联有机锆冻胶压裂液体系。采用单因素试验对交联剂YJ-3和稠化剂RG-1质量分数进行了优化，进而评价了该压裂液体系的性能指标。实验结果表明：压裂液的较优配方组成为0.50%RG-1+2.0%YJ-3+0.15%Na₂S₂O₃+0.8%助排剂，该体系交联时间在3～45 min之间可调，90℃和150℃时在170 s^-1速度下剪切2 h后黏度仍高于50 mPa·s，携砂性能和滤失性明显优于常规瓜胶压裂液体系，在1～3 h内可实现完全破胶，无残渣、易于返排，是一种性能优良的耐温缓交联型低伤害压裂液，具有广阔的现场应用前景。     

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.     

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.