反相悬浮法制备丙烯酸钠与丙烯酰胺共聚物吸水剂

以十八烷基磷酸单酯做分散剂,采用反相悬浮聚合法(ISP)制备了丙烯酸钠与丙烯酰胺共聚物吸水剂。聚合体系稳定,聚合物呈颗粒状,经过滤干燥即得,无需减压蒸馏溶剂。探讨了各种反应条件对聚合物的物理状态,吸去离子水达680ml/g聚合物,吸盐水达68ml/g聚合物。     

EA—MA—AA三元共聚物对铬鞣猪皮的改性研究

采用K_2S_2O_8——NaHSO_3氧化还原引发体系,乳液聚合改性法,研究了EA—MA—AA三元体系对铬鞣猪皮的聚合改性及其性能的影响.并与填充、复鞣等工业改性技术进行实验室对比,考察了三种改性法对降低猪皮部位差的贡献.     

F-12纤维聚合液不溶物的产生原因及控制方法

对F-12纤维聚合液中不溶物的产生原因进行分析,通过对聚合反应工艺的调整,避免聚合液体系不溶物的出现,保证聚合液的均匀.     

Synthesis of tetramethyl-p-silphenylenesiloxanedimethylsiloxane triblock copolymer by employing living anionic polymerization

Dimethylsiloxane-tetramethyl-p-silphenylenesiloxane-dimethylsiloxane (DMS-TMPS-DMS) triblock copolymer was synthesized by employing living anionic polymerization of hexamethylcyclotrisiloxane (D₃). Two synthetic methods were carried out for the polymerization. One of those methods was the anionic polymerization of D₃ initiated at the silanolate anion which was prepared from the terminal hydroxyl group of silanol-terminated TMPS prepolymer by reaction with n-butyllithium (method 1). The other was the coupling reaction of vinyl-terminated TMPS prepolymer with hydrosilyl-terminated DMS prepolymer obtained from the anionic polymerization of D₃ by using diphenylmethylsilanolate anion as initiator (method 2). In method 1, DMS contents of the copolymers ranged from 25.8 to 72.5 wt% and the values agreed with the ratio of D₃ to TMPS prepolymer. The weight-average molecular weights ranged from 1.36×10⁴ to 19.4×10⁴ and were close to the predicted values calculated from the $\text{M}\text{?}{}_{\mathrm{v}}$ of the TMPS prepolymer and the amount of D₃ added. In the case of method 2, weight-average molecular weights ranged from 19.5×10⁴ to 24.2×10⁴. The high molecular weight copolymer could thus be obtained by method 2. Intrinsic viscosity values of the triblock copolymers agreed with calculated values obtained by considering the copolymer as a binary mixture of these homopolymers. Differential scanning calorimetry and thermogravimetry were carried out on the triblock copolymers. The equilibrium melting temperatures of each of the copolymers were very close to that of poly-TMPS (160°C). The glass transition temperature and heat of fusion were decreased as the DMS content was increased. The thermogravimetric curves for the copolymers indicated that the thermal stability of the triblock copolymer was intermediate between the DMS and TMPS homopolymers.     

A viscometric study of the interaction of polybutadienyllithium with N,N,N′,N′-tetramethylethylenediamine in benzene

Moderately concentrated solutions of polystyryllithium in benzene were prepared under high vacuum conditions in an Ubbelohde viscometer and the active chain ends were ‘capped’ with a few molecules of butadiene. The flow times of these solutions were determined before and after the addition of small aliquots of N,N,N′,N′-tetramethylethylenediamine (TMEDA) and finally following protonation of the carbanions with a trace of alcohol. The addition of the TMEDA caused a decrease in the viscosity that was slightly greater than that predicted on the basis that two molecules of TMEDA cause the disaggregation of a dimeric polybutadienyllithium associate.     

Poly(p-tert-butoxycarbonyloxystyrene): a convenient precursor to p-hydroxystyrene resins

An efficient synthetic route to pure, high molecular weight poly(p-hydroxystyrene) is reported. The route involves synthesis of a new monomer, p-tert-butoxycarbonyloxystyrene, polymerization by radical initiation or by cationic initiation in liquid SO₂, followed by thermolysis or acidolysis of the tert-butoxycarbonyl protecting group. Porous, crosslinked resin beads containing the nucleophilic, phenol pendant group have been prepared in a similar fashion from the precursor terpolymer of p-tert-butoxycarbonyloxystyrene, styrene and divinylbenzene. The utility of this resin for solid-phase synthesis has been demonstrated.     

液相及气相植物精油清除DPPH自由基的研究

本文采用分光光度法研究了14种植物精油在液相和气相状态下清除DPPH自由基的能力。实验结果显示不同精油对DPPH自由基有不同的清除效果,在液相和气相条件中,肉桂精油、百里香油、丁香精油的清除效果最好;进一步选取肉桂精油、百里香油、丁香精油进行复配,丁香精油分别与肉桂精油、百里香油复配产生了协同增效效应,特别是丁香精油和百里香油复配时在气相、液相中均具有很好清除DPPH自由基的效果;丁香精油与百里香油复配时,28℃的气相清除率明显高于19℃,19℃时丁香精油占60~80%会出现气相复配增效效应,而在28℃时占20~60%则出现气相复配增效效应,在液相时丁香精油占40~80%出现复配增效效应。在不同的复配比例中,复配物中的不同抗自由基活性成分间会产生协同增效效应。     

Comparative antioxidant activity of nanoscale lignin prepared by a supercritical antisolvent (SAS) process with non-nanoscale lignin

Nowadays, lignin antioxidant study is a hot spot. But some properties of lignin make it hard for a wide range of application. To improve lignin antioxidant activity, we employed supercritical antisolvent (SAS) method for preparation of nanoscale lignin (0.144 ± 0.03 μm) using acetone as a solvent and supercritical carbon dioxide as an antisolvent. The nanoscale lignin was characterised by Scanning Electron Microscopy (SEM), Fourier-Transform Infrared Spectroscopy (FTIR) and X-ray Diffraction (XRD). The results showed that SAS process did not result in lignin degradation or chemical structure change. Due to solubility increase, many antioxidant parameters of the nanoscale lignin were obviously enhanced, including DPPH radical scavenging activity, superoxide radical scavenging activity and reducing power. As an antioxidant, the nanoscale lignin was a better material than the non-nanoscale lignin. Our study was to promote the lignin application in animal husbandry, pharmaceutical and food processing industries.     

骨蛋白酶解物的抗氧化作用

研究了骨胶原蛋白酶解物的总抗氧化能力、羟自由基(·OH)清除作用和抑制超氧阴离子自由基的能力.通过与谷胱甘肽(GSH)的比较发现,溶液质量浓度在100～150 mg/mL时,该骨胶原多肽的总抗氧化能力为GSH的71.92%.溶液质量浓度在2.5～20 mg/mL时,该多肽羟自由基清除作用为谷胱甘肽的1.36倍.溶液质量浓度为10～150 mg/mL时,多肽抑制超氧阴离子自由基的能力低于谷胱甘肽.     

高牢度皮革涂饰剂FS-001的研制

介绍了一种乳液聚合方法。通过种子乳液聚合,调整单体比例,引发剂和乳化剂的品种及数量,确定当丙烯酸丁酯和苯乙烯占单体总量的90%～94%,功能单体N-羟甲基丙烯酰胺和丙烯酸羟乙酯占单体总量的2.5%～4.5%,引发剂用量占单体重量的0.9%,阴、非离子乳化剂比例为1∶3,乳化剂总量为单体总量2%,丙烯酸用量为单体总量的3%～4%时,合成的皮革涂饰剂FS-001牢度高,手感好,柔软丰满,具有良好的市场应用前景。