期刊文献+
共找到323篇文章
< 1 2 17 >
每页显示 20 50 100
Synthesis and Characterization of Poly Styrene-Co-Poly 2-Hydroxyethylmethacrylate (HEMA) Copolymer and an Investigation of Free-Radical Copolymerization Propagation Kinetics by Solvent Effects
1
作者 Anaif M. Alhewaitey Ishrat Khan Naif M. Alhawiti 《Open Journal of Polymer Chemistry》 2024年第1期63-93,共31页
A series of homo and copolymers of styrene (ST) and 2-hydroxyethyl methacrylate (HEMA) in three different media (bulk, tetrahydrofuran, and benzene) have been investigated by free radical polymerization method. The sa... A series of homo and copolymers of styrene (ST) and 2-hydroxyethyl methacrylate (HEMA) in three different media (bulk, tetrahydrofuran, and benzene) have been investigated by free radical polymerization method. The samples obtained from the synthesis were characterized by Fourier Transform-Infrared spectroscopy (FT-IR), proton nuclear magnetic resonance spectroscopy (<sup>1</sup>H NMR), atomic force microscopy (AFM), and differential scanning calorimetry (DSC). The results show that the synthesis of the polymers is more feasible under neat conditions rather than solvent directed reaction. Moreover, the DSC data shows that the polystyrene obtained is amorphous in nature and therefore displayed only a glass transition signal rather than crystallization and melting peaks. In addition, this study indicates that homolopolymerization of styrene via free radical polymerization tends to be preferable in less polar solvents like THF than in non-polar solvents like benzene. Benzene might destabilize the formation of the reactive radicals leading to the formation of the products. In summary, the homolpolymerization of styrene is more feasible than the homopolymerization 2-hydroxyethyl methacrylate under the experimental setup used. Styrene is more reactive than 2-hydroxyethyl methacrylate than free radical polymerization reaction due in part of the generation of the benzylic radical intermediate which is more stable leading to the formation of products than alkyl radical which are less stable. Furthermore, polymerization of styrene under neat conditions is preferable in solvent-assisted environments. The choice of solvent for the synthesis of these polymers is crucial and therefore the selection of solvent that leads to the formation of a more stable reaction intermediate is more favorable. It is worth noting that the structure of the proposed copolymer consists of a highly polar and hydrophilic monomer, 2-hydroxyethyl methacrylate and a highly non-polar and hydrophobic monomer, styrene. These functionalities constitute an amphiphilic copolymer with diverse characteristics. A plausible explanation underlying our observations is that the reaction conditions employed in the synthesis of these copolymers might not be the right route required under free radical polymerization. 展开更多
关键词 2-Hydroxyethyl methacrylate POLYMERIZATION
下载PDF
THE EFFECTS OF N-2-HYDROXYETHYL-N-METHYL-p-TOLUIDINE ON METHYL METHACRYLATE RADICAL POLYMERI-ZATION AND ACRYLONITRILE PHOTOINDUCED POLYMERIZATION
2
作者 丘坤元 张璋华 冯新德 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 1992年第3期250-257,共8页
The effects of N-2-hydroxyethyl-N-methyl-p-toluidine (HMT) on MMA polymerization using organic peroxide as an initiator and on AN photoinduced polymerization have been investigated respectively. The kinetics of polyme... The effects of N-2-hydroxyethyl-N-methyl-p-toluidine (HMT) on MMA polymerization using organic peroxide as an initiator and on AN photoinduced polymerization have been investigated respectively. The kinetics of polymerization and the overall activation energy of polymerization were determined. Based on kinetics study and the end group analysis of the polymer obtained by UV spectrum method, the initiation mechanism is proposed. 展开更多
关键词 HMT THE EFFECTS OF N-2-HYDROXYETHYL-N-methyl-p-TOLUIDINE ON METHYL methacrylate RADICAL POLYMERI-ZATION AND ACRYLONITRILE PHOTOINDUCED POLYMERIZATION BPO HMA MMA DMT LPO
下载PDF
MONOMER REACTIVITY RATIO AND THERMAL PERFORMANCE OFα-METHYL STYRENE AND GLYCIDYL METHACRYLATE COPOLYMERS 被引量:4
3
作者 梁淑君 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2010年第3期323-330,共8页
Synthesis and characterization of the copolymers (PAG) of α-methyl styrene (AMS) and glycidyl methacrylate (GMA) are presented. The copolymers of PAG were characterized by gel permeation chromatography (GPC),... Synthesis and characterization of the copolymers (PAG) of α-methyl styrene (AMS) and glycidyl methacrylate (GMA) are presented. The copolymers of PAG were characterized by gel permeation chromatography (GPC), Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (^1H-NMR) and thermogravimetery (TG). Based on the copolymer compositions determined by ^1H-NMR, the reactivity ratios of AMS and GMA were found to be 0.105 ± 0.012 and 0.883 ± 0.046 respectively by Kelen-Tudos method. TG revealed that thermal stability of the copolymers decreased with increasing the AMS content in the copolymers, which indicated that the degradation was mainly caused by the chain scission of AMS-containing structures. Under heating, the copolymers depolymerize at their weak bonds and form chain radicals, which could further initiate other chemical reactions. 展开更多
关键词 COPOLYMERIZATION α-methyl styrene Glycidyl methacrylate Reactivity ratios DEPOLYMERIZATION
下载PDF
Cs/SiO_(2)-ZrO_(2)催化丙酸甲酯与甲醛缩合反应性能研究
4
作者 杜海岗 王兴永 +3 位作者 孙培永 陈和 傅送保 姚志龙 《无机盐工业》 CAS CSCD 北大核心 2024年第11期165-174,共10页
丙酸甲酯与甲醛缩合制备甲基丙烯酸甲酯(Methyl Methacrylate,简称MMA)是目前较清洁的工艺路线,其关键在于高性能催化剂的开发。采用共沉淀法和初湿浸渍法制备了SiO_(2)-ZrO_(2)复合氧化物和Cs/SiO_(2)-ZrO_(2)催化剂,通过XRD、Raman、I... 丙酸甲酯与甲醛缩合制备甲基丙烯酸甲酯(Methyl Methacrylate,简称MMA)是目前较清洁的工艺路线,其关键在于高性能催化剂的开发。采用共沉淀法和初湿浸渍法制备了SiO_(2)-ZrO_(2)复合氧化物和Cs/SiO_(2)-ZrO_(2)催化剂,通过XRD、Raman、ICP-OES、BET、NH_(3)-TPD和CO_(2)-TPD等手段对其理化性质进行了表征,并将其与催化丙酸甲酯和甲醛的缩合反应的性能进行关联,研究载体表面酸碱性对Cs/SiO_(2)-ZrO_(2)催化剂缩合反应活性的影响。结果表明:SiO_(2)质量分数的增大有利于促进SiO_(2)-ZrO_(2)复合氧化物中m-ZrO_(2)向t-ZrO_(2)的转变以及t-ZrO_(2)晶型的稳定;引入Cs_(2)CO_(3)可使其结构和表面酸碱性位点分布发生改变。催化剂表面弱碱性位点是适宜的活性中心,具有较高催化活性的催化剂表面弱碱性和总碱性位点数量存在一个最优区间,其中中强碱位点的降低和酸性位点的消除有利于催化活性的提高;在0.2 MPa、370℃和质量空速为1.0 h^(-1)的条件下,质量分数为60%的SiO_(2)和质量分数为10%的Cs_(2)CO_(3)组成的10Cs/60SiO_(2)-40ZrO_(2)催化剂具有最佳催化性能,对丙酸甲酯的转化率和目标产物甲基丙烯酸甲酯的选择性分别可达30.77%和97.89%。 展开更多
关键词 甲基丙烯酸甲酯 羟醛缩合 复合氧化物 SiO_(2)-ZrO_(2) 丙酸甲酯
下载PDF
Synthesis of Comblike Poly(methyl methacrylate) by Atom Transfer Radical Polymerization with Poly(ethyl 2-bromoacrylate) as Macroinitiator 被引量:2
5
作者 YanSHI ZhiFengFU +1 位作者 YuDongZHANG ShuKeJIAO 《Chinese Chemical Letters》 SCIE CAS CSCD 2003年第12期1289-1292,共4页
Comblike poly(methyl methacrylate) was synthesized by atom transfer radical polymerization of methyl methacrylate with poly(ethyl 2-bromoacrylate) as a macroinitiator, which was prepared by conventional free radical p... Comblike poly(methyl methacrylate) was synthesized by atom transfer radical polymerization of methyl methacrylate with poly(ethyl 2-bromoacrylate) as a macroinitiator, which was prepared by conventional free radical polymerization of ethyl 2-bromoacrylate. The obtained comblike polymers were characterized by GPC and 1H NMR. 展开更多
关键词 Comblike polymer atom transfer radical polymerization (ATRP) MACROINITIATOR poly(methyl methacrylate) ethyl 2-bromoacrylate.
下载PDF
Injectable bioactive polymethyl methacrylate-hydrogel hybrid bone cement loaded with BMP-2 to improve osteogenesis for percutaneous vertebroplasty and kyphoplasty 被引量:4
6
作者 Xin Sun Xin Zhang +8 位作者 Xin Jiao Jie Ma Xingzhen Liu Han Yang Kangping Shen Yaokai Gan Jinwu Wang Haiyan Li Wenjie Jin 《Bio-Design and Manufacturing》 SCIE EI CAS CSCD 2022年第2期318-332,共15页
Poly methyl methacrylate(PMMA)bone cement is used in augmenting and stabilizing fractured vertebral bodies through percutaneous vertebroplasty(PVP)and percutaneous kyphoplasty(PKP).However,applications of PMMA bone ce... Poly methyl methacrylate(PMMA)bone cement is used in augmenting and stabilizing fractured vertebral bodies through percutaneous vertebroplasty(PVP)and percutaneous kyphoplasty(PKP).However,applications of PMMA bone cement are limited by the high elasticity modulus of PMMA,its low biodegradability,and its limited ability to regenerate bone.To improve PMMA bio activity and biodegradability and to modify its elasticity modulus,we mixed PMMA bone cement with oxidized hyaluronic acid and carboxymethyl chitosan in situ cross-linking hydrogel loaded with bone morphogenetic protein-2(BMP-2)to achieve novel hybrid cement.These fabric ated PMMA-hydrogel hybrid cements exhibited lower setting temperatures,a lower elasticity modulus,and better biodegradability and biocompatibility than that of pure PMMA cement,while retaining acceptable setting times,mechanical strength,and inj ectability.In addition,we detected release of BMP-2 from the PMMA-hydrogel hybrid cements,significantly enhancing in vitro osteogenesis of bone marrow mesenchymal stem cells by up-regulating the gene expression of Runx2,Coll,and OPN.Use of PMMA-hydrogel hybrid cements loaded with BMP-2 on rabbit femoral condyle bone-defect models revealed their biodegradability and enhanced bone formation.Our study demonstrated the favorable mechanical properties,biocompatibility,and biodegradability of fabricated PMMA-hydrogel hybrid cements loaded with BMP-2,as well as their ability to improve osteogenesis,making them a promising material for use in PKP and PVP. 展开更多
关键词 Polymethyl methacrylate bone cement HYDROGEL Bone morphogenetic protein-2 OSTEOGENESIS Percutaneous vertebroplasty
下载PDF
Porous alumina ceramic via gelcasting based on2-hydroxyethyl methacrylate dissolved in tert-butyl alcohol 被引量:4
7
作者 Xiao-feng WANG Yu-zhou XIE +3 位作者 Chao-qun PENG Ri-chu WANG Dou ZHANG Yan FENG 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2019年第8期1714-1720,共7页
To obtain porous alumina ceramic with high strength,a novel gelcasting system based on 2-hydroxyethyl methacrylate(HEMA)dissolved in tert-butyl alcohol(TBA)was developed.The polymerization of the HEMA-TBA gelcasting s... To obtain porous alumina ceramic with high strength,a novel gelcasting system based on 2-hydroxyethyl methacrylate(HEMA)dissolved in tert-butyl alcohol(TBA)was developed.The polymerization of the HEMA-TBA gelcasting system,the thermal behavior of obtained green body,and the microstructures and mechanical properties of the sintered bodies were investigated by rheometer,TG-DSC,SEM and bending strength testing,respectively.The results show that,(1)10 mg/mL of the initiator(benzoyl peroxide)is the optimal amount for polymerization of this gelscasting system at 25 ℃;(2)The alumina suspension of the HEMA-TBA gelcasting system showing shear-thinning behavior is sufficiently low for gelcasting process;(3)The bending strength of porous alumina ceramic samples,whose porosities range from 42% to 56%,is from(8±0.5)to(91±4.5)MPa. 展开更多
关键词 GELCASTING POLYMERIZATION porous ceramic ALUMINA 2-hydroxyethyl methacrylate (HEMA) tert-butyl alcohol (TBA) bending strength
下载PDF
Kinetic Study of Atom Transfer Radical Polymerization of 2-(N,N-Dimethylamino)ethyl Methacrylate 被引量:2
8
作者 江成发 张允湘 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2004年第2期208-213,共6页
A kinetic model was developed to describe the atom transfer radical polymerization (ATRP) of 2(N,N-dimethylarnino) ethyl methacrylate (DMAEMA). The model was based on a polymerization mechanism, which included the ato... A kinetic model was developed to describe the atom transfer radical polymerization (ATRP) of 2(N,N-dimethylarnino) ethyl methacrylate (DMAEMA). The model was based on a polymerization mechanism, which included the atom transfer equilibrium for primary radical, the propagation of growing polymer radical, and the atom transfer equilibrium for the growing polymer radical. An experiment was carried out to measure the conversion of monomer, the number-average molecular weight of polymer and molecular weight distribution for the ATRP process of DMAEMA. The experimental data were used to correlate the kinetic model and rate constants were obtained. The rate constants of activation and deactivation in the atom transfer equilibrium for primary radical are 1.0 x 10(4) L(.)mol(-1.)s(-1) and 0.04 L(.)mol(-1.)s(-1), respectively. The rate constant of the propagation of growing polymer radical is 8.50 L(.)mol(-1.)s(-1), and the rate constants of activation and deactivation in the atom transfer equilibrium for growing polymer radical are 0.045 L(.)mol(-1.)s(-1) and 1.2 x 10(5) L(.)mol(-1.)s(-1), respectively. The values of the rate constants represent the features of the ATRP process. The kinetic model was used to calculate the ATRP process of DMAEMA. The results show that the calculations agree well with the measurements. 展开更多
关键词 KINETICS MODELING atom transfer radical polymerization moment method 2-(N N-dimethylamino)-ethyl methacrylate
下载PDF
Grafting of 2-Hydroxyethyl Methacrylate onto Silk by Atom Transfer Radical Polymerization 被引量:1
9
作者 邢铁玲 肖勇 陈国强 《Journal of Donghua University(English Edition)》 EI CAS 2010年第4期491-495,共5页
Silk was grafted using 2-hydroxyethyl methacrylate(HEMA)by atom transfer radical polymerization(ATRP)method.The amino groups and hydroxyl groups on the side chains of the silk fibroin was reacted with 2-bromoisobutyry... Silk was grafted using 2-hydroxyethyl methacrylate(HEMA)by atom transfer radical polymerization(ATRP)method.The amino groups and hydroxyl groups on the side chains of the silk fibroin was reacted with 2-bromoisobutyryl bromide(BriB-Br)to obtain efficient macroinitiator for ATRP.And the macroinitiator was grafted with HEMA in water aqueous using CuBr/N,N,N',N",N"-pentamethyldiethylenetriamine(PMDETA)as catalyst system.The effects of monomer concentration,the proportion of CuBr and PMDETA,grafting temperature and time on the silk grafting were discussed,and the optimal grafting technology was obtained.FT-IR characterization of the grafted silk showed a peak corresponding to HEMA,which indicated that HEMA was grafted onto the surface of silk.ATRP method could be applied on the silk modification and this technique provided a new way for silk grafting. 展开更多
关键词 atom transfer radical polymerization(ATRP) SILK GRAFTING surface modification 2-hydroxyethyl methacrylate(HEMA)
下载PDF
Nonisothermal Kinetics of Free-Radical Polymerization of 2,2-Dinitropropyl Methacrylate
10
作者 黄咏峰 张公正 徐琴 《Journal of Beijing Institute of Technology》 EI CAS 2010年第4期466-470,共5页
The 2,2-dinitropropyl methacrylate(DNPMA) was synthesized by esterification of α-methacrylic acid with 2,2-dinitropropanol.The free-radical bulk polymerization of DNPMA in the presence of 2,2-azobisisobutyronitrile... The 2,2-dinitropropyl methacrylate(DNPMA) was synthesized by esterification of α-methacrylic acid with 2,2-dinitropropanol.The free-radical bulk polymerization of DNPMA in the presence of 2,2-azobisisobutyronitrile(AIBN) was investigated by differential scanning calorimetry(DSC) in the nonisothermal mode.Kissinger,Ozawa and Barrett methods were applied to determine the activation energy(Ea) and the reaction order of the free-radical polymerization.The results showed that the temperature of exothermic polymerization peaks increased with increasing heating rate.With increasing the molar ratio of monomer/initiator and the heating rate,the reaction order of nonisothermal polymerization was approximately equal to 1.The average Ea value from Kissinger and Ozawa methods(77.74±1.07 kJ/mol) was smaller than the value from the Barrett method(Ea=102.36 kJ/mol). 展开更多
关键词 2 2-dinitropropyl methacrylate DSC free-radical polymerization KINETICS
下载PDF
SYNTHESIS AND POLYMERIZATION OF TRI(2-PYRIDYL)METHYL METHACRYLATE
11
作者 Chuan-fu Chen Yong-hong Yang Fu Xi Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080, China 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 1999年第3期295-298,共4页
A novel methacrylate monomer with bulky side group, tri(2-pyridyl)methyl methacrylate (Tr2PyMA), was synthesized and polymerized. The polymer obtained by radical polymerization exhibits high isotactic tacticity.
关键词 optical activity tri(2-pyridyl)methyl methacrylate
下载PDF
A Novel Polymethyl Methacrylate (PMMA)-TiO_2 Nanocomposite and Its Thermal and Photic Stability
12
作者 ZAN Ling LIU Zhongshi FA Wenjun PENG TianYou 《Wuhan University Journal of Natural Sciences》 CAS 2006年第2期415-418,共4页
A new kind of polymethyl methacrylate (PMMA)-TiO2 nanocomposite was synthesized through polymerization. The thermal and photic stability of this PMMA TiO2 nanocomposites were investigated. The as prepared samples we... A new kind of polymethyl methacrylate (PMMA)-TiO2 nanocomposite was synthesized through polymerization. The thermal and photic stability of this PMMA TiO2 nanocomposites were investigated. The as prepared samples were characterized by scanning electron microscopy (SEM), UV-Vis spectroscopy, differential thermal analysis (DTA) and the photo-induced weight loss, The results show that the photostability of the PMMA-TiO2 nanocomposite is higher than that of the pure PMMA under UV-light irradiation, The weight loss of the pure PMMA reaches 30 % after 300 h UVirradiation, while the composite only 0.3% under the identical experimental condition. The glass transition temperature (TR) of pure PMMA is only 80℃, while the Tg of the composite reaches 258℃. Compared with pure PMMA, the thermal stability of the composite is greatly enhanced. 展开更多
关键词 polymethyl methacrylate PMMA )-TiO2 nanoeomposite POLYMERIZATION thermal and photic stability
下载PDF
Synthesis of Temperature- and pH-Sensitive Graft Copolymer Containing 2-(Diethylamino)ethyl Methacrylate and N-Vinylcaprolactam onto Silicone Rubber
13
作者 Alejandra Jiménez-Morales Alejandro Ramos-Ballesteros Emilio Bucio 《Open Journal of Polymer Chemistry》 CAS 2016年第3期15-26,共13页
Silicone rubber films were modified by the consecutive grafting of 2-(diethylamino)ethyl methacrylate (DEAEMA) and N-vinylcaprolactam (NVCL) using direct method on two steps with gamma-rays. The effect of absorbed dos... Silicone rubber films were modified by the consecutive grafting of 2-(diethylamino)ethyl methacrylate (DEAEMA) and N-vinylcaprolactam (NVCL) using direct method on two steps with gamma-rays. The effect of absorbed dose and monomer concentration on grafting degree was determined. The grafted samples were verified by FTIR-ATR spectroscopy and swelling;thermal properties were analyzed by DSC and TGA. The stimuli-responsive behavior was studied by swelling and/or DSC. Thermo- and pH-sensitive films of (PP-g-DEAEMA)-g-NVCL presented a pH critical at 3.2 and LCST around 63.5℃. 展开更多
关键词 Radiation-Grafting Smart Polymers 2-(Diethylamino)ethyl methacrylate N-VINYLCAPROLACTAM
下载PDF
Characterization ofanovel deep-seamicrobial esterase EstC 10 and its use in the generation o f(R)-methyl 2-chloropropionate 被引量:5
14
作者 GONG Yanhui MA Sanmei +4 位作者 WANG Yongfei XU Yongkai SUN Aijun ZHANG Yun HU Yunfeng 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2018年第2期473-482,共10页
A novel esterase EstC10 from Bacillus sp. CX01 isolated from the deep sea of the Western Pacific Ocean and the functionalities of EstC 10 was characterized. At present, the reports about the kinetic resolution ofracem... A novel esterase EstC10 from Bacillus sp. CX01 isolated from the deep sea of the Western Pacific Ocean and the functionalities of EstC 10 was characterized. At present, the reports about the kinetic resolution ofracemic methyl 2-chloropropionate were quite rare. So we developed deep-sea microbial esterase EstC10 as a novel biocatalyst in the kinetic resolution of racemic methyl 2-chloropropionate and generate (R)-methyl 2-chloropropionate with high enantiomeric excess (〉99%) after the optimization of process parameters such as pH, temperature, organic co-solvents, surfactants, substrate concentration and reaction time. Notably, the optimal substrate concentration (80 mmol/L) of esterase EstC10 was higher than the kinetic resolution of another esterase, Estl2-7 (50 mmoFL). The novel microbial esterase EstC10 identified from the deep sea was a promising green biocatalyst in the generation of (R)-methyl 2-chloropropionate as well of many other valuable chiral chemicals in industry. 展开更多
关键词 BIOCATALYSIS deep-sea microorganisms novel esterase kinetic resolution (R)-methyl 2-chloropropionate
下载PDF
Controlled Self-assembly of Two Coordination Polymers via subtly Varying Bis(2-methyl imidazole) Ligands:from 3-Connected(6,3) Net to 4-Connected sql Net 被引量:4
15
作者 王桂霞 吴海霞 +1 位作者 李召好 赵邦屯 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2014年第7期1074-1080,共7页
Two coordination polymers constructed from 3,4-thiophenedicarboxylic acid and bis(2-methyl imidazole) ligands, namely, {[Cd2(tdc)2(bip)2]·7H20}n (1) and [Cd(tdc)(bib)]n (2) (Hgtdc = 3,4-thiophenedi... Two coordination polymers constructed from 3,4-thiophenedicarboxylic acid and bis(2-methyl imidazole) ligands, namely, {[Cd2(tdc)2(bip)2]·7H20}n (1) and [Cd(tdc)(bib)]n (2) (Hgtdc = 3,4-thiophenedicarboxylic acid, bip = 1,3-bis-(imidazol-2-methyl)propane and bib = 1,4-bis(imidazol-2-methyl)butane), have been synthesized and structurally characterized by single-crystal X-ray diffraction. Structural analyses reveal that 1 exhibits a two-dimensional (2D) layered network with 3-connected (6,3) topology, which is further connected into a three- dimensional (3D) supramolecular structure by intermolecular hydrogen bonds. However, 2 features a 2D network which can be rationalized as a 4-connected sql net. The results indicate the subtle difference of auxiliary bis(imidazol-2-methyl) ligands may lead to diverse architectures. Moreover, they exhibit luminescence emission in the solid state at room temperature. 展开更多
关键词 3 4-thiophenedicarboxylic acid bis(imidazoi-2-methyl ligands crystal structure photoluminescent properties
下载PDF
辐射接枝制备聚甲基丙烯酸N,N-二甲氨基乙酯-TiO_(2)光催化剂及其对Cr(Ⅵ)的吸附还原性能 被引量:1
16
作者 王亚洋 王亦凡 +2 位作者 张彬 杨小洁 李月生 《辐射研究与辐射工艺学报》 CAS CSCD 2023年第1期33-41,共9页
以二氧化钛(TiO_(2))为基材,甲基丙烯酸二甲氨基乙酯(DMAEMA)为单体,采用共辐射接枝法成功合成了聚甲基丙烯酸N,N-二甲氨基乙酯-TiO_(2)(TiO_(2)-g-PDMAEMA)吸附-光催化剂。同时探究了单体浓度和吸收剂量对重金属离子吸附作用的影响。... 以二氧化钛(TiO_(2))为基材,甲基丙烯酸二甲氨基乙酯(DMAEMA)为单体,采用共辐射接枝法成功合成了聚甲基丙烯酸N,N-二甲氨基乙酯-TiO_(2)(TiO_(2)-g-PDMAEMA)吸附-光催化剂。同时探究了单体浓度和吸收剂量对重金属离子吸附作用的影响。利用扫描电镜、X射线衍射仪、傅里叶红外光谱分析仪、热重分析仪、X射线光电子能谱、接触角等表征手段,证实了电子束共辐射接枝法成功将DMAEMA单体接枝到TiO_(2)表面。在吸收剂量为60 kGy、单体浓度为20%时,TiO_(2)-g-PDMAEMA对10 mg/L Cr(Ⅵ)具有较佳的吸附能力,吸附容量可达10.75 mg/g。在可见光诱导下,吸收剂量为60 kGy、单体浓度为10%时,制备的TiO_(2)-g-PDMAEMA具有最佳的吸附-光催化还原能力,对10 mg/L Cr(Ⅵ)的去除率达85.56%。该新型光催化剂上的吸附-光催化协同效应可以满足去除水中Cr(Ⅵ)污染的要求。 展开更多
关键词 二氧化钛 甲基丙烯酸二甲氨基乙酯 辐射接枝 光催化 Cr(Ⅵ) 吸附-光催化还原
下载PDF
EFFECT OF TEMPERATURE ON COPOLYMERIZATION PARAMETERS OF HYDROXYETHYL ACRYLATE AND METHYL METHACRYLATE
17
作者 李欣欣 印啸敏 +2 位作者 吴平平 韩哲文 朱清仁 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 1998年第1期25-31,共7页
The copolymerization of 2-hydroxyethyl acrylate (HEA, M//1) and methyl methacrylate (MMA, M//2) in cyclohexanone was studied. The multiple experiments of solution copolymerization with low conversion were carried out... The copolymerization of 2-hydroxyethyl acrylate (HEA, M//1) and methyl methacrylate (MMA, M//2) in cyclohexanone was studied. The multiple experiments of solution copolymerization with low conversion were carried out at two sensitive composition feed points at 60, 80, 100, 120 and 140 degree C, respectively. The composition of the copolymers was analyzed by **1H-NMR. The reactivity ratios which were estimated by the Error-in-Variable Method (EVM) of Mayo-Lewis equation were found to be r//1 equals 0.328, r//2 equals 1.781 for 60 degree C; 0.375, 1.709 for 80 degree C; 0.406, 1.654 for 100 degree C; 0.439, 1.540 for 120 degree C and 0.455, 1.400 for 140 degree C, and the 95% joint confidence intervals of the reactivity ratios were also determined. According to r//1 and r//2, Arrhenius relations and the activity energy difference between the homo- and cross-propagation were calculated. (Author abstract) 12 Refs. 展开更多
关键词 reactivity ratio 2-Hydroxyethyl acrylate methyl methacrylate COPOLYMERIZATION copolymer composition
下载PDF
HELIX SENSE-SELECTIVE COPOLYMERIZATION OF TRIPHENYLMETHYL METHACRYLATE WITH CHIRAL ANIONIC INITIATORS
18
作者 任长玉 陈传福 习复 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 1994年第4期379-384,共6页
Optically active copolymers of pairs of three monomers, triphenyl (methyl methacrylate)and one or two pyridyl substituted methyl methacrylate homologues, were obtained by helix-sense-selective copolymerization using c... Optically active copolymers of pairs of three monomers, triphenyl (methyl methacrylate)and one or two pyridyl substituted methyl methacrylate homologues, were obtained by helix-sense-selective copolymerization using complexes of organolithium with chiral ligand as anionicinitiators in toluene at low temperature. The copolymers obtained with (-)-sparteine (Sp) and(S,S)-(+)-and (R, R)-(-)-2, 3-dimethoxy-1, 4-bis (dimethylamino) butanes((+)-and (-)-DDB) complexes of organolithium showed low optical activity, but PMP complex with N, N-diphenylethyleneamine monolithium amide (PMP-DPEDA-Li) was effective in synthesizingcopolymers of high optical rotation ([α]_D^(25) about+320~1370°)which were comparable to thoseof relative homopolymers with one-handed helical structure. 展开更多
关键词 Phenyl [bis (2-pyridyl) methyl methacrylate (s)-(+)-1-(2pyrrolidinyl-methyl) pyrrolidine (PMP) Anionic asymmetric copolymerization Optically active copolymer
下载PDF
Theoretical Study on the Reaction Mechanism of o-Aminophenol, Acetic Acid and Phosphorus Oxytrichloride One-pot to Form 2-Methyl Benzoxazole
19
作者 ZHANG Fu-Lan 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2018年第12期1869-1877,1843,共10页
The reaction mechanism of o-aminophenol, acetic acid and phosphorus oxytrichloride in one-pot to form 2-methyl benzoxazole was studied by density functional theory. The geometries of the reactants, transition states, ... The reaction mechanism of o-aminophenol, acetic acid and phosphorus oxytrichloride in one-pot to form 2-methyl benzoxazole was studied by density functional theory. The geometries of the reactants, transition states, intermediates and products were optimized at the GGA/PW91/DNP level. Vibration analysis was carried out to confirm the transition state structure. Two possible reaction pathways were investigated in this study. The result indicates that the reaction Re→TS1→IM1→TSA2→IMA2→TSA3→IMA3→TSA4→IMA4→TSA5→P2 is the main pathway, the activation energy of which is the lowest. Re→TS1→IM1 is the rate-limiting step, with the activation energy being 221.54 kJ·mol^(-1) and the reaction heat being 10.06 kJ·mol^(-1). The dominant product predicted theoretically is in agreement with the experiment results. 展开更多
关键词 O-AMINOPHENOL acetic acid phosphorus oxytrichloride 2-methyl benzoxazole density functional reaction mechanism
下载PDF
XRD Pattern of Liquid Crystal Monomer Acrylate That Conjugated with Cholesterol and p-Hydroxyphenyl-2-Methyl Butanoic
20
作者 Afrlzal Muhammad Hikam +1 位作者 Bambang Soegiyono Asep Riswoko 《Journal of Chemistry and Chemical Engineering》 2012年第12期1051-1055,共5页
It was successfully synthesized liquid crystal monomer acrylate that conjugated with two mesogens were cholesterol and p-hydroxyphenyl-2-methyl Butanoat which called MA (monomer cholesteryl acrylate) and monomer (S... It was successfully synthesized liquid crystal monomer acrylate that conjugated with two mesogens were cholesterol and p-hydroxyphenyl-2-methyl Butanoat which called MA (monomer cholesteryl acrylate) and monomer (S)-(+)-4-(2-Methyl butanoat-l-butyloxy) phenyl 4-[1-(propenoyloxy) butyloxy] benzoate (MB). Two monomers were characterized by DSC (differential scanning calorimetry), POM (polarization optical microscopy) and XRD (X-ray diffraction). Mesophase temperatures of MA and MB are 81.28 ~C and 54.36~C, respectively. Textures analysis by POM shows that MA was oily streak and MB was schlieren. XRD pattern shows the strongest three peaks of MA at room temperature which are (20, deg): 2.7153, 5.2992 and 18.8500. The Strongest three peaks of MB at room temperature are (20, deg): 9.1726, 9.7707 and 12.5389. XRD pattern of MA and MB at mesophase and above mesophase temperature that each peaks disappear. 展开更多
关键词 Liquid crystal cholesteryl acrylate p-hydroxyphenyl-2-methyl butanoat.
下载PDF
上一页 1 2 17 下一页 到第
使用帮助 返回顶部