Fe2+-H2O2引发体系对淀粉接枝共聚改性为絮凝剂的影响研究

为克服引发剂铈盐较昂贵,工业应用难的缺点,实验采用Fe2 -H2O2引发体系引发丙烯腈接枝改性淀粉,采用接枝率和接枝效率作为评价接枝效果的指标,详细研究了接枝的工艺及其引发剂浓度、丙烯腈单体的用量和接枝温度对接枝率和接枝效率的影响。接枝后对接枝淀粉的结构分析表明:淀粉大分子上已接枝上丙烯腈单体;接枝反应不仅发生在淀粉的无定形区也发生在结晶区,且接枝后接枝淀粉的结晶度有所提高。     

氧化还原体系引发淀粉—丙烯酸接枝共聚的研究

研究了空气存在下，Ｈ２Ｏ２－Ｆｅ＾２＋、Ｋ２Ｓ２Ｏ８－Ｆｅ＾２＋、ＫＰＳ－ＮａＨＳＯ３、ＫＰＳ－ＣＨ３ＯＨ等氧化还原体系引发淀粉－丙烯酸的接枝共聚反应，探索了ＫＰＳ－ＮａＨＳＯ３引发聚合时的最佳操作方法。     

淀粉接枝共聚引发体系的研究

研究了以硝酸铈铵（CAN）、硝酸铈铵-乙二胺四乙酸二钠（CAN-EDTA）、硝酸铈铵-过硫酸钾（CAN—KPS）三种引发体系分别引发淀粉接枝丙烯酰胺共聚反应。通过正交实验并作图，找到了它们的最佳工艺条件。应用其最佳工艺条件下的接枝率（G）、单体转换率（CM）和引发剂用量来比较三者中的最佳引发体系。试验最终得出，硝酸铈铵一过硫酸钾（CAN-KPS）复合引发体系是三者中最好的。     

淀粉接枝共聚引发体系的研究

研究了以硝酸铈铵(CAN)、硝酸铈铵-乙二胺四乙酸二钠(CAN-EDTA)和硝酸铈铵-过硫酸钾(CAN-KPS)三种引发体系分别引发淀粉接枝丙烯酰胺共聚反应.通过正交实验并作图找到了最佳工艺条件.应用其最佳工艺条件下的接枝率(G%)、单体转换率(CM%)和引发剂用量来比较了三者中的最佳引发体系.本实验中最终得出以硝酸铈铵-过硫酸钾(CAN-KPS)复合引发体系是三者中最好的.     

氧化还原引发木薯淀粉与丙烯酰胺接枝共聚的研究

以木薯淀粉和丙烯酰胺为原料,采用氧化还原引发体系合成淀粉-丙烯酰胺接枝共聚物,研究了温度、引发剂浓度、单体浓度以及反应时间对聚合反应的影响。结果表明：采用氧化还原引发剂可以使聚合反应低温快速进行。实验最佳条件：反应温度为40℃,引发剂浓度为4mmol／L,单体质量浓度为85mg／mL,反应时间为3h。     

Ce^4＋引发体系对淀粉接枝共聚反应的影响研究

研究和介绍了淀粉－丙烯腈接枝共聚反应中引发剂的作用机理及影响因素,通过实验确定了铈盐引发体系的最佳操作条件。     

淀粉接枝改性絮凝剂研究进展

对淀粉接枝絮凝剂的研究进展进行了综述。     

氧化还原引发淀粉与丙烯酸接枝共聚研究

研究了马铃薯淀粉与丙烯酸的接枝共聚反应,以过硫酸钾-亚硫酸氢钠为氧化还原引发体系,考察了不同引发剂浓度、单体浓度、反应温度、反应时间等对单体转化率、接枝率和接枝效率的影响;用红外光谱对共聚物进行了表征。结果表明,采用氧化还原引发体系可使聚合反应低温快速进行,并确定反应较佳条件。     

淀粉接枝型高分子絮凝剂的合成

用硝酸铵作引发剂,研究了淀粉－丙烯酰胺接枝共聚物高分子絮凝剂制备的工艺条件。实验结果表明,影响接枝聚合后反应的最佳工艺条件为：硝酸胺浓度１．０＊１０＾－３ｍｏｌ／Ｌ,单体丙烯酰胺浓度１．４ｍｏｌ／Ｌ,聚合反应温度５０℃,聚合反应时间３ｈ。同时,还探讨了淀粉接枝聚合反应的机理。     

淀粉接枝丙烯酰胺絮凝剂的制备和应用

以可溶性玉米淀粉和丙烯酰胺为原料,高锰酸钾/草酸为引发剂,制备了淀粉接枝丙烯酰胺聚合物絮凝剂,考查了淀粉与丙烯酰胺质量比、引发剂质量、反应温度、反应时间等对接技效率的影响。结果表明淀粉与丙烯酰胺质量比为1:2,引发剂质量为0.35g,50℃反应3h接枝效率最高,处理高岭土溶液有较好的絮凝效果。     

淀粉接枝丙烯腈制备絮凝剂的工艺优化及应用研究

研究了淀粉接枝丙烯腈的各种因素对接枝率和接枝效率的影响。结果表明,接枝改性淀粉絮凝剂的最佳工艺条件:可溶性淀粉与丙烯腈的质量比为1∶3,硝酸铈铵的浓度为6 mg/L,接枝温度为35℃,接枝时间为2 h。在此条件下,接枝率可达172%,接枝效率92%。所制得高分子絮凝剂较无机絮凝剂对较高浓度的有机废水有较好的浊度、COD去除率及沉降速度。     

淀粉醋酸酯与醋酸乙烯接枝共聚制备白乳胶

提出了用淀粉醋酸酯与醋酸乙烯接枝共聚制备白乳胶的新工艺。结果表明制得的白乳胶与单独用PVA作为保护胶体制得的白乳胶相比,粘度和耐水性得到改善,粘接强度均能达到使用标准。作为一种新型胶粘剂,其与环境相容性好,前景广阔。     

Studies on the grafting of acryloylated potato starch with styrene

An investigation of graft polymerization to determine the potential of a starch‐bonded acryloyl group as a suitable coupling agent with vinyl monomers was carried out. In this case, potassium persulfate was used as a free‐radical initiator using water as the reaction solvent for further graft polymerization. This work revealed the ability of water as a reaction medium; perhydroxyl and hydroxyl radicals were easily formed from persulfate to produce free radicals to activate the styrene monomer towards grafting with acryloylated potato starch. The graft copolymers were characterized by FT‐IR spectroscopy and further confirmed using saponification. The analysis results showed the grafted potato starch with the styryl chain afforded protection to the ester bond, which resisted the alkaline hydrolysis. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 452–459, 2005     

Controlled grafting of poly(vinyl acetate) onto starch via RAFT polymerization

A structure‐exact starch‐based xanthate agent was prepared and used as chain transfer agent to mediate RAFT polymerization of vinyl acetate, which offered a convenient way to well control the structure and composition of starch‐g‐poly(vinyl acetate). The structures of the intermediate and the polymer were verified with FTIR and ¹H‐NMR. Gel permeation chromatography measurement results indicated that the polymerization was performed as expected. It was found that the relationship between number average molecular weight and monomer conversion was linear. The polydispersity index of grafted side‐chain ranged from 1.19 to 1.53 and most of them were around 1.2. There was one more degradation stage appeared on the thermogravimetric analysis profile of starch‐g‐poly(vinyl acetate) than that of starch. TEM observation exhibited that the product was able to self‐assemble into micelles in aqueous solution, which suggested the copolymer was amphiphilic. Both the thermal and amphiphilic properties demonstrated the starch‐g‐poly(vinyl acetate) was successfully synthesized as well. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

氧化还原引发下的淀粉、丙烯酸反相乳液聚合

以环己烷为连续相,Span20为乳化剂,采用氧化还原引发体系,通过反相乳液聚合技术,合成淀粉、丙烯酸接枝共聚物。并用红外光谱对共聚物进行了表征。研究结果表明:采用氧化还原引发剂可使聚合反应低温快速进行,在过硫酸钾为3.1mmol/L,亚硫酸氢钠为3.1mmol/L,单体丙烯酸浓度为2.6mol/L,反应温度为30℃,反应时间为3h,乳化剂浓度为5%时,单体转化率为92.6%、淀粉接枝率为43.2%、淀粉接枝效率56.4%。     

PS接枝PA6共聚合研究

采用熔融接枝法制备PA6-g-PS共聚物,研究了原料配比(PA6：PS)、引发剂用量(DCP％)和反应温度(T)对接枝效率的影响。结果表明：产物PA6-g-Ps的接枝效率随DCP%的增加及T的升高,均呈现先上升后下降的趋势;而随PA6：PS的增加则一直呈下降趋势。同时,对PA6-g-Ps接枝共聚产物进行FITR、X-射线衍射分析。     

Solid state grafting copolymerization of acrylamide onto poly(vinyl alcohol) initiated by redox system

A solid state grafting copolymerization of acrylamide (AM) onto poly(vinyl alcohol) (PVA) was conducted with ammonium persulfate and sodium bisulfite redox system as initiators. Before the reaction the PVA powder and required amount of AM were mixed evenly, and sprayed with water to swell the PVA powder and to dissolve AM. Then the swollen PVA powder was sprayed with the redox solution, and the reaction temperature was controlled at a temperature between 30°C and 80°C for 120 min. The grafting percentage and efficiency were determined as functions of monomer/PVA ratio, initiator concentration and reaction temperature. The structure and performance of the graft copolymers were confirmed by FTIR‐ATR, XRD, ¹³C NMR, and thermogravimetric analysis, together with mechanical property and apparent viscosity measurements. It has been confirmed that grafting copolymerization of AM onto PVA initiated by this redox system occurred with higher grafting percentage and efficiency in the solid state. The thermal stability and water‐solubility of grafted PVA were found to be better than those of unmodified PVA. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39938.     

生物絮凝剂ZL 5-2的絮凝特性研究

ZL 5-2是土壤杆菌M-503产生的一种新型生物絮凝剂。经组分分析和薄层层析分析,表明ZL 5-2是一种含有少量蛋白的多糖类物质。通过对絮凝活性影响因素的研究,发现Ca2+,Ba2+,Mg2+,Mn2+及A l3+对絮凝活性具有促进作用,其中Ca2+助凝效果最好;ZL 5-2在pH值为6—12下保持很高絮凝活性,耐碱性良好;ZL 5-2在4—121℃下保留了绝大部分的絮凝活性,表现出良好的热稳定性;胃蛋白酶、胰蛋白酶、三氯乙酸及α-淀粉酶、纤维素酶、-β1,4葡聚糖酶等糖苷酶作用于ZL 5-2,对絮凝活性均无明显影响;-β1,3葡聚糖酶可降解ZL 5-2中的多糖物质,但对絮凝活性无明显影响。