锦16块深部液流转向驱油技术

辽河锦16块油井综合含水超过90%,近井地带调剖的效果已很差.研发了一种聚合物/酚醛成胶体系,该体系在30～110℃下可在数小时到教天内形成储能模量G'在0.2～2.0 Pa的可流动弱凝胶,与油基预交联聚合物J5(60～120目)一起,用作深部液流转向剂.讨论了该弱凝胶的组成与配方.试验区有4口水井,15口油井.其中两口水井处理半径15 m,分3个段塞注入J5颗粒量递增(5.0～8.0g/L)的1.5g/L HPAM溶液;另两口水井处理半径18 m,第一段塞为HPAM溶液携带J5颗粒,第二、第三段塞分别为低、高交联的3.0g/L聚合物弱凝胶.注入后注水压力上升,10口可对比油井中3口井无效果,7口井见效,产液量减少,含水下降,产油量增大.     

N,N,N-trimethyl chitosan nanoparticles as a vitamin carrier system

There is considerable interest in incorporating stabilized vitamins into biopolymeric nanoparticles, especially in the development of carriers and active systems for pharmaceutical and food applications. Amongst biopolymer, chitosan is highly desirable owing to its good biocompatibility, biodegradability and ability to be chemically modified. In this paper, nanoparticles from three kinds of water-soluble derivative chitosan (N,N,N-trimethyl chitosan, TMC) have successfully been synthesized by ionic gelation with tripolyphosphate (TPP) anions. Combinations of concentrations of TMC and TPP have resulted in nanoparticles with varying sizes for which the capability for loading with vitamins was investigated. Zeta potential measurement and particle size analysis demonstrated that the size of the nanoparticles was optimized (196 ± 8 nm) when the lowest TMC and TPP amounts were used, i.e., 0.86 mg mL⁻¹ and 0.114 mg mL⁻¹ respectively. As the TMC and/or the TPP concentrations increase, the resulting size of the nanoparticles increases considerably. Three different vitamins (B9, B12 and C) were tested as additives and the final system characterized in relation to size, morphology, spectroscopic and zeta potential properties. In general, the incorporation of vitamins increased all the TMC–TPP original nanoparticle sizes, reaching a maximum diameter of 534 ± 20 nm when loaded with vitamin C. The presence of vitamins also decreases the zeta potential, with one exception observed when using vitamin C. The preliminary results of this study suggested that all TMC/TPP nanoparticles can be successfully used as a stable medium to incorporate and transport vitamins, with potential applications in foodstuffs.     

Experimental Design in the Preparation of Modified HEMA-Based Superporous Hydrogels in an Aqueous Medium

Due to a relatively large number of excipients and their concentrations, which can be used effectively in the preparation of superporous hydrogels, an experimental design based on the Taguchi matrix has proven to be a very valuable tool in screening and narrowing down the final formulation. In this study, the effect of starting materials, their concentrations as well as the starting reaction temperature, were examined in the preparation of superporous hydrogels based on hydroxyethyl methacrylate. A large number of possible formulations and conditions might lead to the production of a reasonable hydrogel network, but some formulations produce stronger or faster swelling superporous hydrogels than others. The final properties of the superporous hydrogels depend upon the events that occur during formation of the gel, including the presence of atmospheric oxygen, which is responsible for the inhibition period seen at the start of the reaction, and also including the change in temperature at which the reaction starts. These events can be largely affected by the choice of ingredients used in the reaction. For this study, eight variables were chosen, and their effects were examined using a Taguchi matrix. The parameters examined were the maximum temperature during the reaction, the time corresponding to the maximum temperature, and the reaction yield which is represented by the weight of the dry final SPH.     

环境友好型无铬高温高压水基钻井液的应用研究

介绍了一种环境友好型高温高压水基钻井液体系,该体系使用新型无铬合成聚合物,具有稳定的高温流变性,能有效控制钻井液高温高压滤失量、防止钻井液高温胶凝。现场应用结果表明,基于新型无铬合成聚合物的高温高压水基钻井液配方具有良好的灵活性,可用于开发适用于不同要求的环境友好型高温高压水基钻井液体系。     

Formulation and release of doxycycline HCL from an ion activated in situ gelling delivery system for the treatment of periodontal disease

This study reports on the formulation of doxycycline HCL in an ion activated in situ gelling delivery system and its implications for the treatment of periodontal disease. The system is based on the use of alginate as the gelling agent and hydroxypropyl methylcellulose (HPMC) as a viscosity enhancing agent. The ion activated gelling mechanism in this system is based on the concept of interaction with the divalent calcium ions present in the gingival crevicular fluid (GCF). The gelling capacity of the prepared formulations was assessed visually and by investigating their rheological behavior upon mixing with human blood serum since it has the same composition as the GCF. The rheological behavior of all formulations was not affected by incorporation of the drug. In vitro release studies showed that the alginate/HPMC mixture, upon gelling after mixing with serum, can sustain the release of doxycycline HCL for an extended period of time which was more than 12 days. These results indicated that this system can be used as an in situ gelling local delivery system for the treatment of periodontal disease. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Structure and properties of poly(vinyl alcohol)/κ‐carrageenan blends

Blends of a commercial atactic poly(vinyl alcohol) (a‐PVA) derived from vinyl acetate and κ‐carrageenan were prepared by mixing the aqueous solutions of both samples. Blend films prepared by casting were transparent. In the DSC curves of the blend films, the endothermic peaks shifted to lower temperature with an increase of the content of κ‐carrageenan. The Young's modulus and the strength at break increased with an increase of the content of a‐PVA. As the standing temperature of the blend solutions decreased, the gelation region increased also at high content of carrageenan. In the amorphous regions of blend films, a‐PVA and κ‐carrageenan were miscible. © 2001 Society of Chemical Industry     

Are disulphide bonds formed during acid gelation of preheated milk?

The role of thiol/disulphide exchanges during acid gelation of preheated milk was studied with milk samples with or without N‐ethylmaleimide (NEM), a thiol‐blocking agent, and acidified to pH 4 by the addition of glucono‐delta‐lactone at 20 °C. Active or total thiol groups, particle size with light scattering measurements in a dissociating solvent or by SDS‐agarose electrophoresis were determined on acidified milk samples. Diffusing wave spectroscopy and rheology in low strain were applied during acidification of sample, while rheology in large strain was applied on final acid gels. The only effect of the presence of NEM was a reduced firmness of acid gels as measured at large strain and a reduced tendency to form large aggregates at pH<5.5. In conclusions, thiol/disulphide exchanges during acidification of milk played only a minor role in the building of acid gel networks from heated milk.     

Crosslinking of mixtures of diglycidylether of bisphenol‐A with 1,6‐dioxaspiro[4.4] nonan‐2,7‐dione initiated by tertiary amines: III. Effect of hydroxyl groups on network formation

BACKGROUND: Blends of epoxy resin oligomers, diglycidylether of bisphenol‐A (DGEBA), and a bislactone, 1,6‐dioxaspiro[4.4]nonan‐2,7‐dione (s(γBL)), were anionically copolymerized using two tertiary amines as anionic initiators. Their curing rheology and gelation behaviour were studied to provide a more comprehensive knowledge of the curing of these previously studied systems. RESULTS: The activation energy for gelation was found to be similar to that previously measured using differential scanning calorimetry and appeared to increase in the presence of the bislactone. The reaction rate during copolymerization of DGEBA with s(γBL) was slower than DGEBA homopolymerization alone because the alkoxide attack on the epoxide is faster than the reaction of the carboxylate ion and the epoxy group. The effect of the initiator type on the gel conversion was small and was presumably due to differences in the kinetic chain length caused by amine regeneration from the quaternary amine. For the same initiator and at a constant ratio of DGEBA/s(γBL), an increase in the hydroxyl concentration of the DGEBA oligomer raised the gel conversion. For a DGEBA oligomer with low hydroxyl levels, an increase in the concentration of s(γBL) increased the gel conversion; however, for a DGEBA oligomer with high hydroxyl levels, increasing s(γBL) concentration decreased the gel conversion. CONCLUSION: These results are interpreted in terms of the effect of initiation rate and chain transfer rate on the kinetic chain length. The glass transition temperature of the gel was found to be controlled by the fraction of the aliphatic s(γBL) and the amount of plasticizing sol in the matrix. Copyright © 2009 Society of Chemical Industry     

纸板粘合用的高分子树脂粘合剂

本章论述了具有高湿粘性的硼酸化了的聚乙烯醇粘合剂.它由聚乙烯醇树脂,水溶性硼化物及具1,2羟基或1,3羟基的多元醇所组成.这种聚乙烯醇溶液的pH值较低,为新颖纸板粘合剂的生产提供了组合成份.它不但防霉、防潮、无毒,且成本低廉,对纸箱厂行业来说,是可以接受的技术改进.进一步的研究,是用高湿粘性粘合剂来减少金属表面的腐蚀,以及在使用强酸才不致凝胶的系统中,使用具高湿粘性硼酸化的聚乙烯醇溶液.