自降解屏蔽暂堵剂PAM/PCL的合成及性能研究

针对生物降解塑料聚己内酯（PCL）耐温性能差、高温条件下降解时间快等缺点,本文以丙烯酰胺（AM）和PCL为主要原料,N,N-亚甲基双丙烯酰胺（MBA）为交联剂、过硫酸铵（APS）和亚硫酸氢钠（SHS）为引发剂、失水山梨糖醇脂肪酸酯（Span-80）和乙基纤维素为分散剂,采用反相悬浮聚合法合成了一种自降解暂堵剂,考察了分散剂、搅拌速度、交联剂、油水比和引发剂对暂堵剂降解时间的影响,确定了暂堵剂最佳合成条件：分散剂用量（质量分数,下同）0.4%、搅拌速度400 r·min^-1、油水比（体积比）8:2、交联剂用量0.8%、引发剂用量0.5%。对暂堵剂的性能进行了评价,实验结果表明：暂堵剂具有较好的耐温耐盐性,耐温可达160 ℃,与钻井液配伍性较好,少量暂堵剂就可以有效降低钻井液的滤失量。砂床封堵实验表明：暂堵剂具有较好的封堵性能,暂堵剂用量为0.5%就可使砂床浸入深度减少6.5 cm。     

酸压用自降解颗粒暂堵剂的制备与性能评价

暂堵酸压技术是改造碳酸盐岩储层、提高储层渗透性、保证油井增产稳产的有效措施。其中,暂堵剂是暂堵酸压技术的关键。本文采用水溶液聚合法制备了一种酸压用自降解颗粒暂堵剂TDJ,通过室内实验对TDJ进行了配方优化、降解性、封堵性及解堵性等研究。结果表明：反应温度为60 ℃, 30%丙烯酰胺,1%乙氧基化三羟甲基丙烷三丙烯酸酯,0.3%过硫酸铵合成的TDJ性能最好。TDJ适用地层温度为60~120 ℃,其降解时间受HCl浓度和NaCl溶液浓度影响,在1%HCl中完全降解需要85 h,20%HCl中完全降解需要67 h;在10000 mg/L NaCl溶液中完全降解需要10 h, 70000 mg/L NaCl中完全降解需要18 h。岩心实验表明：TDJ具有良好的封堵性能和解堵性能,暂堵率和解堵率分别达到90%和92%以上。      

新型高吸水聚合物凝胶型屏蔽暂堵剂MTC-1的合成及性能

以丙烯酸（AA）、丙烯酰胺（AM）、2-丙烯酰胺基-2-甲基丙磺酸（AMPS）为原料，蒙脱土（MMT）为改性剂，过硫酸钾和无水亚硫酸氢钠为氧化还原引发体系，六亚甲基四胺（C₆H₁₂N₄）为交联剂，采用水溶液聚合法合成了一种新型高吸水聚合物凝胶型屏蔽暂堵剂（MTC 1），其结构经IR表征。在最优合成条件（AM/AMPS/AA=11/7/1, m/m/m，引发剂加量0.6 wt%，于45 ℃反应2.5 h）下，MTC-1的最大吸水倍率为1006倍。岩心流动实验结果表明：MTC-1的堵水性能较高，封堵效率达到83.72%。     

广谱“油膜”暂堵剂在油层保护技术中的应用

针对油层非均质性强、孔径分布范围较宽、油层孔径难以准确预知,常规屏蔽暂堵技术几乎无法实现对整个油层井段的保护、油层保护效果差等特点,设计了广谱“油膜”暂堵型保护油层钻井完井液体系,并进行了室内系统评价和现场应用。结果表明,当广谱“油膜”暂堵剂GPJ的加量达到3%时,可在近井壁处形成很好的屏蔽暂堵“油膜”带,渗透率堵塞率和恢复率皆大于90%,与常规屏蔽暂堵技术相比,可使油层损害程度降低7.4~10倍,产量提高1.82~2.96倍,而且与油层渗透率和温度无关。     

粉煤灰复合聚丙烯酸钠凝胶的制备及其溶胀性能

粉煤灰(CFA)存在的情况下,采用自由基溶液聚合法,以过硫酸钾(KPS)为引发剂,N,N'-亚甲基双丙烯酰胺(NNMBA)为交联剂,制备了粉煤灰复合聚丙烯酸钠凝胶(CFAPAANa)。 以丙烯酸单体质量为基准,当交联剂用量为0.08%,引发剂用量为0.4%,粉煤灰用量为3%,丙烯酸中和度为70%,聚合温度为70 ℃时,所合成的粉煤灰复合聚丙烯酸钠凝胶在蒸馏水和生理盐水中平衡溶胀比最高,分别为1556(g/g)和168(g/g)。 考察了复合凝胶在不同介质溶液中的溶胀动力学,保水性能以及在土壤中的降解行为。 溶胀动力学研究表明,蒸馏水中溶胀初期复合凝胶聚合物链段的扩散运动能够调控凝胶溶胀的快慢及程度,而生理盐水中水分子的平移和对流运动在凝胶的溶胀过程中起着关键性作用。 保水和降解实验结果表明,25 ℃时,50 h凝胶保水率为64%,土壤中50 d时降解率达60%。 相比于聚丙烯酸钠凝胶,粉煤灰复合凝胶保水率提高了8%。     

P(AMPS-co-HEMA)凝胶的合成与吸银性能研究

以2-丙烯酰胺基-2-甲基丙磺酸(AMPS)和甲基丙烯酸羟乙酯(HEMA)为单体,N,N′-亚甲基双丙烯酰胺(MBA)为交联剂,过硫酸钾(KPS)为引发剂,采用自由基水溶液聚合法制备P(AMPS-co-HEMA)共聚凝胶,通过傅里叶红外光谱(FT-IR)对材料结构进行了表征.研究单体配比、交联剂的用量、引发剂的用量对共聚凝胶吸水性能的影响,并在此基础上对凝胶的溶胀、吸银及消溶胀性能进行研究.结果表明,当单体摩尔比n(AMPS)∶n(HEMA)=2∶1,交联剂用量ω(MBA)=0.6％,引发剂用量ω(KPS)=0.8％,所制得的凝胶吸水性能最好;凝胶在蒸馏水中的溶胀过程属于松弛平衡扩散;凝胶在AgNO3溶液中60min左右达到消溶胀平衡,且当AgNO3溶液的浓度为0.05mol/L时,银离子吸附量最大,为0.04g/g,消溶胀速率最快.     

载药聚甲基丙烯酸-2-羟乙酯水凝胶膜的制备及性能

选择(NH4)2S2O8为引发剂,N-N′-亚甲基双丙烯酰胺(MBA)为交联剂,十二烷基硫酸钠(SDS)为制孔剂,通过改变水凝胶膜的溶剂与单体的配比、交联剂和制孔剂的量等制备出不同性质的水凝胶膜,运用电镜扫描、含水率、电子拉力机等表征不同水凝胶膜的性能.本研究尝试将硫酸新霉素药物作为载入药物导入水凝胶中,进行载药和缓释能力测试.实验结果表明,当单体甲基丙烯酸羟乙酯与水的比例为1∶3,引发剂过硫酸铵含量为单体1.0%(w/V),SDS为4.0%(w/V),MBA为4.0%(w/V)时,水凝胶的含水率为42.84%,拉伸强度为0.32MPa,药物缓释累积达峰时间为8.17h,综合性能较佳.     

双网络结构冻胶堵剂在高温高盐下的性能研究

针对塔河油田高温、高盐等缝洞油藏堵水困难的技术难题,构建了双网络结构的冻胶堵剂体系。以N-(3-二甲胺丙基)甲基丙烯酰胺(DMAPMA)和氯乙酸钠(ClCH₂COONa)为原料合成甜菜碱单体TCJ,与单体甲基丙烯酰氧乙基三甲基氯化铵(DMC)和N-(3-二甲氨基丙基)甲基丙烯酰胺(DMAPMA)共聚合成疏水缔合聚合物CDD。采用矿化度为22×10⁴ mg/L的实际地层水,以0.8%(AM/AMPS)聚合物FZ、1.2%酚醛交联剂、0.15%CDD和0.05%特种交联剂CN-10在130℃条件构建互穿双网络结构冻胶CDD-FZ。冻胶性能测试结果表明,双网络冻胶CDD-FZ,仅3 h就能成胶并且成胶强度为H级,最大屈服应力为326.42 Pa,突破压力为88.19MPa/m,30天脱水率1.14%,较传统单层网络结构冻胶具有更高的强度、耐盐性、耐温性和耐稀释性。该研究填补了塔河油田耐温抗盐高强度堵水冻胶的技术的空白,具备较好的实际应用前景。     

沉淀聚合法制备单分散聚(4-乙烯基吡啶-co-二乙烯基苯/三羟甲基丙烷三甲基丙烯酸酯)聚合物微球

以4-乙烯基吡啶(4-VP)为功能单体、二乙烯基苯(DVB)和三羟甲基丙烷三甲基丙烯酸酯(TRIM)为混合交联剂,偶氮二异丁腈(AIBN)为引发剂,乙腈为反应介质,采用沉淀聚合法制备单分散聚合物微球.考察了共聚单体、溶剂、引发剂等聚合条件对聚合物微球粒径、分散性以及产率的影响.并用扫描电镜(SEM)、激光粒度分析仪、热重分析仪和红外光谱对微球进行了表征.结果表明,聚合物微球的表面形貌和产率可通过改变溶剂体积、单体/交联剂摩尔比和引发剂浓度等因素进行控制.降低乙腈溶液体积、增加DVB摩尔比例及交联剂摩尔比、可增加聚合物粒径及粒度分布均匀性,而聚合物产率随溶剂体积和DVB摩尔比增大而减小,随交联剂摩尔比和引发剂浓度的增加而增加.在最优条件下,即DVB和TRIM两者摩尔比4∶1,单体/交联剂摩尔比1∶5,乙腈用量为5.6 m L(单体和交联剂占介质体积的7%),引发剂浓度为2 wt%~6 wt%(占总反应单体的量)时,可获得形貌规则、产率较高的单分散poly(4-VP-co-DVB/TRIM)微球,微球平均粒径约4.02μm,粒径分布指数(U)为1.013.此外,热重分析结果显示,聚合微球于350℃时开始分解,600℃时失重率达84.9%.     

玉米秸秆/羧甲基纤维素复配水凝胶水分释放行为

以粉碎的玉米秸秆(RCS)和羧甲基纤维素(CMC)为原料,制备了含水质量分数可达97.47%的玉米秸秆/羧甲基纤维素复配水凝胶(RCS/CMC)。考察了交联剂、CMC和RCS用量对RCS/CMC凝胶模量的影响,凝胶在缓冲溶液中的降解行为和土壤中的失重行为,以及凝胶对土壤持水量、玉米种子萌发的影响。结果表明,与对照实验比较,RCS/CMC凝胶可以提高土壤持水率1.00%~1.61%,在37 ℃缓冲溶液中用纤维素酶处理4 d后降解率约80%,土壤中25 d后失重约94%;用CMC/RCS凝胶处理玉米种子,虽然平均延长了种子萌发时间,但种子的萌发率较高。其中相对湿度18%、20%、23%、26%、28%和30%的萌发试验,由于水分胁迫对照实验种子不能萌发,而CMC/RCS凝胶处理的种子发芽率仍可达到97%。     

Preparation and photocatalytic degradability of TiO2/polyacrylamide composite

Based on the unique absorbent characters and three-dimensional network structure of polyacrylamide (PAM) superabsorbent polymer, a photocatalytic degradable TiO₂/PAM composite was synthesized by an aqueous solution polymerization method with N,N′-methylene bisacrylamide as crosslinker, potassium peroxydisulfate as initiator, acrylamide as monomer, and TiO₂ (P-25) as functional filler. The photocatalytic degradability of the composite was evaluated using methyl orange as photodegradation target, and the recovery and reproducibility of the composite was investigated. It was found that TiO₂/PAM composite had a good photocatalytic degradability, the composite also possessed a good reproducibility of photocatalytic degradability, which is possible to be used in practical process.     

Synthesis and properties of a novel plugging agent based on the PAN microspheres with sodium carbonate

A new plugging agent, which derived from the copolymer of polyacrylonitrile, was successfully synthesized by using acrylonitrile as monomer, poly(ethylene glycol) diacrylate as cross-linker, AIBN as initiator, cyclohexane as solvent, and anhydrous sodium carbonate as the alkaline additive, its structure and surface morphology were characterized using FTIR and SEM. As key investigation parameters, in an aqueous environment, the gel viscosity η and distribution of particle size with different dosage of Na₂CO₃, the gel viscosity η with aging time, and the slow release mechanism of Na₂CO₃ in resulting plugging agent were investigated, its gel procedure was also described.     

Experimental study of polyacrylamide gel in close‐in well operation

An optimized polymer gel, known as temporary gel, based on polyacrylamide sulfonated copolymer, and a chromium acetate hydroxide were synthesized to close‐in the wells during applying well servicing work. Based on bottle tests, polymer gel with 28 000 ppm of polymer concentration, and 0.105 ratio of crosslinker to polymer, was selected. The pressure effect within the range of 1000 to 4000 psi indicated not impressive effect of pressure on the gel properties. As the results of creep test clarified, yield strength of the gel was measured at temperature of 90°C, and 2000 Pa. Moreover, the results of an experiment under simulated well condition showed a linear correlation between the height of polymer gel column, and the strength and persistence of gel against fluid pressure. At last, process of degelling with 40 g of optimum gel was performed using 14 g of 30 wt% solution of citric acid during 4 hours.     

含甲基丙烯酸-N,N-二甲氨基乙酯水凝胶的紫外辐射合成及其性质研究

紫外光辐照 ,H2 O2 为光引发剂 ,N ,N′ 亚甲基双丙烯酰胺为交联剂合成了含甲基丙烯酸 N ,N 二甲氨基乙酯的水凝胶 .研究了水溶液中单体、光敏引发剂、交联剂浓度及光照时间对生成的水凝胶的凝胶含量和溶胀性能的影响 ,给出了最佳合成条件 .用该聚合法合成的聚甲基丙烯酸 N ,N 二甲氨基乙酯水凝胶不仅具有较好的透明性和适当的弹性 ,而且在 40℃和 pH =3时有明显的温度及 pH敏感性 .但离子强度对凝胶溶胀性能没有明显影响     

PAMPS/SiO_2杂化水凝胶的合成及电场敏感性研究

以2-丙烯酰胺-2-甲基丙磺酸(AMPS)为有机原料,正硅酸乙酯(TEOS)为无机原料,过硫酸钾为引发剂,N,N'-亚甲基双丙烯酰胺为交联剂,通过原位-凝胶水溶液聚合法合成了一系列不同二氧化硅含量和不同聚离子浓度的聚(2-丙烯酰胺-2-甲基丙磺酸)/二氧化硅杂化电场敏感性水凝胶.通过扫描电子显微镜(SEM)表征凝胶的结构,研究水凝胶在去离子水以及氯化钠溶液中的溶胀和消溶胀行为.结果表明,系列凝胶的平衡溶胀度介于224.9至325.6之间,复合凝胶的溶胀速率随TEOS用量的增加而降低;除理想杂化凝胶外,随着聚离子浓度的升高,凝胶在氯化钠溶液中的消溶胀速率逐渐减小.对凝胶的电场敏感性研究表明,当聚离子浓度大于氯化钠溶液浓度时,凝胶进一步溶胀,反之则消溶胀,其中杂化凝胶的再溶胀性能减弱,而消溶胀行为变得更为明显.同时制得的理想杂化凝胶,较纯有机凝胶具有更为理想的力学性能,最大抗压缩强度可达23.4 MPa.     

Study on the Plugging Ability of Polymer Gel Particle for the Profile Control in Reservoir

Polymer gel particle is a widely used deep profile control agent to plug the water breakthrough channel in reservoir. However, there is still no theoretical model to describe its plugging ability available when it is applicated. Based on the Hertz contact theory and force analysis, the plugging model of polymer gel particle is established at the view of pore throat, and the parameters in the model are achieved by the pore throat experiments. The plugging model is verified by the core experiments. The results show that the plugging strength of polymer gel particle keeps rise with the increasing of the ratio between particle diameter and pore throat size, and then it will stay at a stable value because of the limitation of material strength. The material strength is 0.32 MPa and the particle will be broken when the size ratio is over 3. The plugging strength of the polymer gel particles with the diameters of 30–40 µm and 60–80 µm is 0.12 and 0.31 MPa in the cores with the permeability of 2989.6 × 10^?3 and 3014.7 × 10^?3 µm², respectively, which is consistent perfectly with the theoretical calculation. The plugging model of polymer gel particle is verified to be correct and can be applied to the profile control in reservoir.     

聚丙烯酰胺凝胶结构非均匀性的动态光散射研究

利用动态光散射技术研究了聚丙烯酰胺 (PAAm)凝胶结构的非均匀性 ,分析了PAAm凝胶结构非均匀性的形成原因及凝胶动态光散射的数据处理方法和分析结果的物理意义 .研究结果表明 ,PAAm凝胶中含有动态相关长度 (LC)不同的两相 ,其中 ,LC 为 10～ 2 0nm的区域是聚合物稀疏相 ,LC 为 85nm左右的区域是聚合物密集相 ,两相的不均匀分布形成了PAAm凝胶结构的非均匀性 .分析表明 ,PAAm凝胶存在两相主要是由于单体和交联剂的溶解度存在差异所致 .随交联度增大 ,PAAm凝胶结构的非均匀性显著增强     

双网络增强自支撑多层膜的制备

通过石英晶体微天平(QCM)研究不同最外层对单体、交联剂、引发剂扩散入多层膜的结果显示,聚乙烯亚胺( PEI)为最外层的多层膜更有利于负电荷分子扩散.将(聚乙烯亚胺/聚丙烯酸)12-聚乙烯亚胺[( PEI/PAA)12-PEI]多层膜浸入带有单体、引发剂、交联剂的溶液后,经过光聚合交联与热交联后可形成自支撑膜.XPS数...     

Synthesis and degradation behavior of poly(ethyl cyanoacrylate)

Poly(ethyl cyanoacrylate) was synthesized using N,N′-dimethyl-p-toluidine as an initiator through an anionic/zwitterionic pathway. The degradability and the degradation mechanism of the prepared polymer were examined from various viewpoints. A combination of TGA and GPC analysis allowed us to confirm that the thermal degradation of this polymer was predominantly due to an unzipping depolymerization process initiated from the polymer chain terminus. The polymer was inherently unstable and exhibited interesting degradation behavior in solution with basic reagents. The degradation in solution was also found to be attributed to the unzipping of the monomer from the chain end. However, the degradation behavior of the polymer could be controlled by changing solvents, temperatures, and additives. These findings give an insight into the degradation behavior of poly(alkyl cyanoacrylate)s, which is a crucial point in utilizing these polymer homologues for various applications.