共查询到20条相似文献,搜索用时 86 毫秒
1.
KMnO4引发魔芋粉-丙烯腈的接枝共聚反应 总被引:6,自引:0,他引:6
以KMnO4为引发剂进行魔芋粉与丙烯腈的接枝共聚反应。研究了魔芋粉预氧化时间、引发剂浓度、单体浓度、酸度、反应时间、反应温度和反应物加料方式等聚合条件对接枝效率的影响,并对接枝机理作了探讨。 相似文献
2.
高锰酸钾/硫脲引发魔芋粉-丙烯酰胺接技共聚合及产物增稠性研究 总被引:7,自引:1,他引:7
用高锰酸钾/硫脲为引发剂,引发魔芋粉(KGM)与丙烯酰胺(AM)的接枝共聚。研究了引发剂浓度、单体浓度、酸度、反应温度、反应时间、反应介质以及KGM预处理方式等对接枝反应的影响,同时还研究了产物的水溶性及增稠性,并探讨了接枝反应机理。 相似文献
3.
[Mn(H_2P_2O_7)_3]~(3-)引发淀粉与丙烯腈接枝聚合反应的动力学研究 总被引:5,自引:2,他引:5
以[Mn(H_2P_2O_7)_3]~(3-)为引发剂,研究了丙烯腈与玉米淀粉的接枝共聚反应。由实验结果求出了反应速率与引发剂浓度、单体浓度、淀粉浓度和反应温度的关系,推导并验证了接枝反应动力学模型,探讨了反应机理,求得了接枝反应活化能。 相似文献
4.
淀粉乙酸酯的阴离子接枝己内酯聚合研究 总被引:5,自引:0,他引:5
将淀粉在二甲基甲酰胺、吡啶存在下 ,以乙酸酐进行部分乙酰化 ,制备取代度为 0 7~ 1 9的淀粉乙酸酯 (St Ac) .以萘钠与淀粉乙酸酯中残余的羟基反应 ,将羟基转化为醇盐 (ONa) ,引发己内酯进行阴离子开环接枝聚合 ,合成了淀粉 聚己内酯接枝共聚物 (St g PCL) .采用凝胶渗透色谱法 (GPC)研究了接枝前后聚合物分子量的变化情况 ,并以接枝率、单体转化率对接枝反应进行了表征 .研究了接枝条件如温度、溶剂、引发剂和单体的用量对接枝率及单体转化率的影响 .研究发现随着反应温度升高 ,接枝率、单体转化率呈S曲线变化 ,单体浓度、引发剂浓度的增大有利于接枝反应的进行 . 相似文献
5.
6.
7.
8.
9.
10.
11.
Zbigniew Florjanczyk Marek Siudakiewicz 《Journal of polymer science. Part A, Polymer chemistry》1986,24(8):1849-1862
The free-radical polymerization of methyl methacrylate (MMA) initiated by systems comprizing benzoyl peroxide (BPO) and different organoaluminium compounds (OACs) has been studied. The influence of the type of OAC, concentration of components of the initiation system, temperature, and time on the reaction yield have been determined. Systems containing BPO and diethylaluminium chloride (Et2AlCl) have been found to enable us to obtain, in high yields at room temperature, of homopolymers of MMA, methyl acrylate, acrylonitrile (AN), vinyl acetate, and the alternating AN/styrene (St) copolymer; they are, however, not very active in the homopolymerization of St and vinyl chloride. Factors affecting the polymerization yield have been discussed in terms of the mechanism of the reaction between BPO and OACs, reactivity of alkyl radicals formed in these systems, and catalytic effect of OAC in the propagation step. 相似文献
12.
Daniel Hork Ostap Chaykivskyy 《Journal of polymer science. Part A, Polymer chemistry》2002,40(10):1625-1632
Poly(2‐hydroxyethyl methacrylate‐co‐N,O‐dimethacryloylhydroxylamine) particles were prepared by dispersion polymerization in toluene/2‐methylpropan‐1‐ol medium using cellulose acetate butyrate and dibenzoyl peroxide (BPO) as a steric stabilizer and initiator, respectively. The particle size was reduced with decreasing solvency of the reaction medium (more nuclei were generated) because the critical chain length of the precipitated oligomers decreased with an increasing toluene content, which is a poorer solvent for the polymer than 2‐methylpropan‐1‐ol. There is an optimum initiator concentration (2 wt % BPO relative to monomers) for producing low‐polydispersity particles under given conditions. Additionally, discrete spherical particles were obtained at a low monomer concentration and/or higher polymerization temperature. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 1625–1632, 2002 相似文献
13.
过氧化物引发交联聚ε-己内酯的研究 总被引:1,自引:0,他引:1
以过氧化苯甲酰(BPO)为引发剂,对聚ε-己内酯(PCL)进行交联,研究了过氧化物含量,交联温度和交联时间对交联反应的影响,较高的交联温度可以提高BPO引发交联反应的速率.采用DSC、WAXD和DMA等方法对交联后聚ε-己内酯的结晶行为、玻璃化转变、力学性能及其生物降解特性进行了研究.结果表明,交联PCL的结晶度下降,熔点降低,玻璃化转变温度降低,但结晶温度有所提高.交联PCL的断裂伸长率和杨氏模量均下降.但是仍具有完全的生物降解能力. 相似文献
14.
Aqueous chromium(II) ions, Cr(aq)(2+), react with benzoylpyridine oxide (BPO) much more rapidly than with other pyridine N-oxides previously explored. The kinetics were studied under pseudo-first order conditions with either reagent in excess. Under both sets of conditions, the major kinetic term exhibits first order dependence on limiting reagent, and second order dependence on excess reagent, i.e.k(Cr) = k2(Cr)[BPO][Cr(aq)(2+)]2 (excess Cr(aq)(2+)), and k(BPO) = k2(BPO)[Cr(aq)(2+)][BPO](2) (excess BPO), where k2(Cr) = (6.90 +/- 0.27) x 10(4) M(-2) s(-1) and k2(BPO) = (3.32 +/- 0.28) x 10(5) M(-2) s(-1) in 0.10 M HClO4. The rate constant k2(Cr) contains terms corresponding to [H+]-independent and [H+]-catalyzed paths. In the proposed mechanism, the initially formed Cr(aq)(BPO)(2+) engages in parallel oxidation of Cr(aq)(2+) and reduction of BPO. The latter reaction provides the basis for a convenient new preparative route for the BPO complex of Cr(III). 相似文献
15.
Yi-Hao Huang Yet-Pole I Nan-Chi Chen Sheng-Hung Wu Jao-Jia Horng Yung-Tin Wu I-Jyh Wen 《Journal of Thermal Analysis and Calorimetry》2013,113(2):595-598
Benzoyl peroxide (BPO) has been used as initiator or medicine in the chemical industries. Several thermal runaway reactions, fires, and explosions have occurred in Taiwan due to its thermal reactivity and explosive properties. A serious accident was analyzed occurring at Fu-Kao Chemical Plant in Taiwan because of runaway reaction in a batch reactor including methyl acrylate (MA), acrylic acid (AA), and BPO. This accident resulted in one death and more than 100 injuries. Differential scanning calorimetry and thermogravimetry (TG) were used to investigate and calculate the thermal hazard and safety parameter of BPO. Finally, the effects of MA and AA mixed with BPO by DSC/TG were analyzed in this study. The T 0 of BPO was 109 °C in this study. Therefore, the T 0 of BPO/MA was calculated to be 105 °C by DSC. AA and MA were identified as catalyst for thermal decomposition of BPO. 相似文献
16.
关于在同一分子中既含有给电子生色基团又含有受电子碳碳双键基的单体的合成、聚合及它们的光化学行为,我们所报道过的多是一元不饱和羧酸的衍生物。本文报道含有给电子生色基因的1,2-不饱和二元羧酸类单体N-(4-二甲氨基苯基)马来酰亚胺(DMAPMI)的合成、聚合及其光化学行为。 相似文献
17.
N-(p-Dimethylaminophenyl)maleimide (DMAPMI) was synthesized and copolymerized with vinyl acetate. The photochemical behavior of DMAPMI and its polymer was studied. It was found that the intensity of monomer was lower than that of its copolymer due to the structural self-quenching effect as we have reported previously. The relationship between Stern-Volmer constant and 'e' value of quenchers was discussed. DMAPMI could act as both of a photosensitizer for vinyl polymerization upon UV irradiation and a component of redox initiation system by combining with BPO to initiate the vinyl thermo-polymerization. 相似文献
18.
采用sol-gel法成功制备了一系列有望用于高温质子交换膜燃料电池的新型磺化聚醚砜(SPES)/磷酸硼(BPO4)复合膜, 并经热重分析(TGA)-傅立叶变换红外光谱(FTIR)联用技术、差示扫描量热仪(DSC)、扫描电子显微镜(SEM)等对膜的结构和性能进行了表征. 结果表明, 复合膜较纯SPES膜具有更高的热稳定性和玻璃化转变温度, 较低的溶胀性及较高的氧化稳定性; SEM图片显示BPO4在聚合物基体中的分布十分均匀, 这将有利于连续质子传输通道的形成; 复合膜的质子传导率随BPO4含量的增加而增加, 当温度超过120 ℃后, 复合膜仍保持着较高的质子传导率, 这表明该复合膜在高温质子交换膜燃料电池中具有良好的应用前景. 相似文献
19.
Xiangcao Li Xuejian Xing Shaojing Zhao Shaohua Zhu Benhua Wang Minhuan Lan Xiangzhi Song 《中国化学快报》2022,33(3):1632-1636
Benzoyl peroxide(BPO) has been added in wheat flour because of its bleaching effect. However, the abnormal used BPO has caused increasing concern due to its strong oxidization capability which may have adverse effects on living organisms. Herein, we present a carbon dot(CD)-based fluorescent and colorimetric probe for visually, sensitively and selectively sensing BPO. The addition of BPO could quench the red fluorescence of CDs peaked at 622 and 677 nm, and decrease the absorbance at 613 nm, whi... 相似文献