共查询到19条相似文献,搜索用时 203 毫秒
1.
2.
3.
4.
5.
N—[1-(2-吡咯烷酮基)甲基]丙烯酰胺类的聚合及其水凝胶于淑艳,李福绵(北京大学化学系,北京,100871)关键词N-[1-(2-吡咯烷酮基)甲基]丙烯酸胺、氧化-还原引发体系、超高分子量、平衡吸水率N一【l一(2一毗咯烷酮基)甲基]丙烯酸胺(P... 相似文献
6.
过硫酸钾引发丙烯酰胺微乳液聚合 总被引:16,自引:0,他引:16
以山梨醇酐单月桂酸醋(Span20)和聚氧乙烯山梨醇酐单硬醋酸酯(Tween60)的混合物为乳化剂制备丙烯酰胺微乳液,研究了体系中Tween60浓度、水相丙烯酰胺浓度对微乳液电导行为的影响.用过硫酸钾引发微乳液聚合,发现聚合开始后,体系电导率迅速下降,在聚合进入恒速期后电导不再降低.聚合的动力学表达式为:Rp∝[AM]1.17[E]-1.26[I]0.5;Mv∝[AM]1.05[E]-0.94[I]-0.62.它与常规乳液聚合的动力学相差较大,却类似于悬浮聚合. 相似文献
7.
(R)-N-酰基四氢噻唑-2-硫酮-4-羧酸在DCC存在下与胺的反应 总被引:1,自引:2,他引:1
由N-乙酰四氢噻唑-2-硫酮-4-羧酸([α]20D-109.83°),及N-苯甲酰四氢噻唑-2-硫酮-4-羧酸([α]20D-112.22°),在N,N′-二环己基二亚胺(DCC)存在下分别与环己胺、苯胺反应得到光学活性产物(R)-N-乙酰四氢噻唑-2-硫酮-4-甲酰环己胺([α]17D-74.5°),及(R)-N-苯甲酰四氢噻唑-2-硫酮-4-甲酰苯胺([α]19D-7.04°)。用量子化学PM3方法研究了反应物和产物的电子结构。 相似文献
8.
用改装的国产CDR-1型DSC仪研究了苯基缩水甘油醚(PGE)和环氧树脂(E-51)以双-[4-(二苯硫翁基)苯基]硫-二-六氟化磷引发的光聚合。研究了引发剂浓度,光强,温度等因素对聚合反应的影响。对于PGE,聚合速率与引发剂浓度的0.90次方,与光强的0.78次方成比例。对于E-51,聚合速率与引发剂浓度的0.87次方式成比例,而与光强的关系则比较复杂。温度分别超过70℃(对PGE)或80℃(对 相似文献
9.
铁-芳烃络合物光引发剂的吸收光谱研究陈旭东,黄新华陈用烈,梁兆熙(西南师范大学化学系重庆,630715)(中山大学高分子研究所广州)关键词铁-芳烃络合物,光引发剂,吸收光谱,光解铁-芳烃络合物作为环氧化物阳离子聚合光引发剂已引起人们关注[1,2].我... 相似文献
10.
11.
12.
13.
14.
SWELLING AND WETTABILITY OF LIGHT-CURED METHACRYLATE-BASED DENTAL RESINS PREPARED FROM CHOLIC ACID 总被引:1,自引:0,他引:1
2 '-methacryloxy-3α, 7α 12α- trimethacryloyl cholic acid ethyl ester (CAGE4MA) has been prepared from cholic acid. Photo-polymeric resins were prepared from CAGE4MA. 2,2-bis[4-(2-hydroxy-3-methacrylyloxypropoxy)phenyl]propane (bis-GMA) was used for comparison, triethyleneglycol dimethacrylate (TEGDMA) was used as diluent. The polymerization was initiated by camphoroquinone (CQ)/N, N-dimethylaminoethyl methacrylate (DMAEMA) system. The conversion of CAGE4MA was 39% when the reaction time is 60s, which is lower than bis-GMA and TEGDMA.The swelling value of CAGE4MA resin was 0.41% in distilled water, which is much lower than those of bis-GMA resin (2.04%) and TEGDMA resin (4.77%) under the same conditions. Copolymers from CAGE4MA and TEGDMA have been prepared. With the increase of TEGDMA in mixture, the degree of conversion of CA GE4MA and swelling value increased. The swelling values of photocured resins in 0. 1mol/L HCl were also measured. 相似文献
15.
含胺基功能性单体的聚合研究 XIV.含二甲氨基丙烯酰类衍生物与过硫酸钾引发体系引发的丙烯酰胺聚合 总被引:1,自引:7,他引:1
The polymerization of acrylamide (AAm) initiated by the combination of N-(N', N'-dimethylaminomethylene)methacrylamide (DMAMMA) or N, N,-dimethylaminoethyl methacry-late with potassium persulfate were studied kinetically. The rate equation for the AAm polymerization initiated by the above initiation systems were given asRp- Kp[AAm][K2S2O8]1/2[DMAMMA]1/2 Rp=Kp[AAm][K2S2O8]1/2[DMAEMA]1/2 respectively. The overall activation energies for the above polymerization were determined to be 8.7 Kcal/mol and 9.2 Kcal/mol respectively. The UV analysis for the PAAm initiated by the above initiation systema showed that the polymerizable amines,DMAMMA and DMAEMA notonly joined the redox initiation but also incorprated into the AAm polymer chains. The super high molecule weight,107of PAAm were obtained by using these initiation systems. 相似文献
16.
Xu ZK Dai QW Wu J Huang XJ Yang Q 《Langmuir : the ACS journal of surfaces and colloids》2004,20(4):1481-1488
A novel method for the surface modification of a microporous polypropylene membrane by tethering phospholipid analogous polymers (PAPs) is given, which includes the photoinduced graft polymerization of N,N-dimethylaminoethyl methacrylate (DMAEMA) and the ring-opening reaction of grafted poly-(DMAEMA) with 2-alkyloxy-2-oxo-1,3,2-dioxaphospholanes. Five 2-alkyloxy-2-oxo-1,3,2-dioxaphospholanes, containing octyloxy, dodecyloxy, tetradecyloxy, hexadecyloxy, and octadecyloxy groups in the molecular structure, were used to fabricate the PAP-modified polypropylene membranes. The attenuated total reflectance FT-IR spectra of the original, poly(DMAEMA)-grafted, and PAP-modified membranes confirmed the chemical changes on the membrane surface. Scanning electron microscope pictures showed that, compared with the original membrane, the surface porosities ofpoly(DMAEMA)-grafted and PAP-modified membranes were somewhat reduced. Water contact angles measured by the sessile drop method on PAP-modified membranes were slightly lower than that on the original polypropylene membrane, but higher than those on poly(DMAEMA)-grafted membranes with the exception of octyloxy-containing PAP-modified membranes. However, BSA adsorption experiments indicated that the five PAP-modified membranes had a much better protein-resistant property than the original polypropylene membrane and the poly(DMAEMA)-grafted membranes. For hexadecyloxy- and octadecyloxy-containing PAP-modified membranes, almost no protein adsorption was observed when the grafting degree was above 6 wt %. It was also found that the platelet adhesion was remarkably suppressed on the PAP-modified membranes. All these results demonstrate that the described approach is an effective way to improve the surface biocompatibility for polymeric membranes. 相似文献
17.
《高分子科学》2016,(10)
Cationic poly(styrene-co-N,N-dimethylaminoethyl methacrylate)(P(St-co-DMAEMA)) latexes were prepared in the absence of surfactant by using 2,2'-azobis(2-methylpropionamidine) dihydrochloride(AIBA) as the initiator. The effects of the AIBA concentration, HCl/DMAEMA molar ratio and DMAEMA amount on the emulsion polymerization and the latex properties were investigated. The particle morphology and size, the zeta potential and the amino distribution of the P(Stco-DMAEMA) latexes were characterized by transmission electron microscope(TEM), dynamic light scattering(DLS) and conductometric titration, respectively. Results showed that the emulsion polymerization performed smoothly with high monomer conversion and narrow particle size distribution under the optimized conditions with AIBA concentration of1 wt%, HCl/DMAEMA molar ratio of 1.2 and DMAEMA content of 5 wt%. The diameter of the dried latex particles decreased and the density of amino groups on the particle surfaces increased with increasing the DMAEMA content. The zeta potential of the P(St-co-DMAEMA) latexes was p H-dependent and the zero point was around at p H 7.2. A facile method was developed to fabricate P(St-co-DMAEMA)/laponite hybrid nanoparticles via electrostatic adsorption, in which the loading capacity of laponite platelets reached 17.7 wt%, and the resultant hybrid nanoparticles showed good thermal stability. 相似文献
18.
A Novel Approach for the Surface Modification of Polymeric Membrane with Phospholipid Polymer 总被引:1,自引:0,他引:1
QingWenDAI ZhiKangXU JianWU 《中国化学快报》2004,15(8):993-996
A new economic and convenient method to modify the surface of microporous polypropylene (PP) membranes with phospholipid polymer was given. The process included the photo-irradiated graft polymerization of N,N-dimethylaminoethyl methacrylate (DMAEMA) and the ring-opening reaction of the grafted polyDMAEMA with 2-alkyloxy-2-oxide-1,3,2-dioxo-phospholanes (AOP). Four AOPs, whose alkyloxy groups consisted of dodecyl, tetradecyl,hexadecyl and octadecyl moieties, were used to convert the grafted polyDMAEMA to phospholipidpolymers. FT-IR spectra confirmed the chemical change of membrane surface. Platelets adhesion experiment indicated that PP membrane with excellent blood compatible surface could be fabricated by this method. 相似文献
19.
SURFACE MODIFICATION OF MICROPOROUS POLYPROPYLENE MEMBRANES BY GRAFT POLYMERIZATION OF N,N-DIMETHYLAMINOETHYL METHACRYLATE 总被引:2,自引:0,他引:2
Surface modification of microporous polypropylene hollow fiber membranes was performed by radical-induced graft polymerization of N,N-dimethylaminoethyl methacrylate (DMAEMA). The influences of temperature, monomer concentration and pre-adsorbed amount of benzoyl peroxide on grafting degree were studied respectively. It was found that the appropriate graft temperature was 75℃, at which the grafting degree was the highest and the hydrolytic decomposition of DMAEMA the lowest. Scanning electron photomicrography and the average pore diameters of the modified membranes demonstrated that part of the micropores on the membrane surface was plugged by the grafted polyDMAEMA chains, especially at high grafting degree. Contact angle and water swelling experiments showed that a moderate grafting degree could improve the hydrophilicity of the membranes. In the range of I 1.3%o-12.0% grafting degree, the water swelling percentage reached its maximum (51.1%) and the contact angle reached its minimum (74 degrees). The bovine serum albumin (BSA) adsorption experiment indicated that the grafted polyDMAEMA had a dual effect on protein adsorption. At the first stage, the BSA adsorption decreased with increasing of DMAEMA grafting degree. As the interaction between BSA and polyDMAEMA on membrane surface increased, the BSA adsorption increased with increasing of DMAEMA grafting degree. 相似文献