接枝淀粉浆料干法接枝反应的研究

为探讨新型接枝淀粉浆料(能替代PVA用于涤棉纱上浆)的制法,在干法条件下制备了接枝淀粉浆料.研究了反应温度、引发剂用量、反应时间及接枝单体用量对接枝淀粉接枝率、接枝效率和接枝单体转化率的影响.结果表明:ω(引发剂)=2%(对淀粉质量)、ω(接枝单体)=50%(对淀粉质量),35℃反应3.5 h条件下,可以得到接枝率和接枝效率均佳的接枝淀粉;扫描电镜(SEM)显示有聚合物接枝到淀粉颗粒表面;结构分析表明发生了共聚反应,产物为丙烯酸、丙烯酰胺、丙烯酸丁酯与淀粉的接枝共聚物.     

GMA单体对大豆蛋白纤维接枝改性的研究

以甲基丙烯酸缩水甘油酯（GMA）为单体,过硫酸铵（APS）为引发剂,对大豆蛋白纤维织物进行接枝改性,研究接枝率的影响因素,并测试接枝改性对大豆蛋白纤维织物性能的影响.结果表明,较佳的接枝条件为GMA单体用量20%～70%（owf）,引发剂用量1%（对单体重）,冰醋酸浓度0.5g/L,反应温度80℃,时间60min;接枝处理后织物的白度稍有增加,干态折皱回复性有所提高,但强力有所下降.通过红外光谱和纤维形态扫描电镜照片,证实了接枝共聚物的存在.     

尼龙66织物微波法接枝丙烯酰胺的阻燃改性

采用微波接枝法,将丙烯酰胺(AM)接枝到尼龙66织物的表面。研究引发剂浓度、单体浓度、反应时间和反应温度对接枝率的影响,得到的优化反应条件为:引发剂浓度3%、单体浓度20%、反应温度80℃、反应时间90 min。采用衰减全反射-红外光谱和扫描电镜分析表征,接枝单体成功接枝到尼龙66织物表面;热重分析(TG)表征接枝后织物的热稳定性明显提高;极限氧指数(LOI)及垂直燃烧表征接枝后织物的耐燃烧性能明显改善。     

接枝氧化淀粉工艺条件的优化

探讨能替代PVA的接枝变性淀粉的生产工艺条件。以氧化玉米淀粉为原料、过硫酸铵为引发剂、乙酸乙烯酯和丙烯酸丁酯为单体进行接枝共聚反应,并将所制得的接枝变性淀粉用于T/C 65/35 13 tex纱的上浆,用正交试验法探讨了引发剂用量、单体用量、反应时间、反应温度对浆纱耐磨性能、断裂强力、毛羽的影响试验得出最优工艺条件为过硫酸铵用量为单体总量5.5%,乙酸乙烯酯:丙烯酸丁酯为4:6,反应温度为55℃,反应时间为3.00h。认为在优化条件下制得的接枝变性淀粉浆料具有较好的上浆性能,可替代PVA用于涤棉混纺纱的上浆。     

紫外光引发丙烯酰胺接枝改性棉织物亲水性的研究

以丙烯酰胺（AM）为接枝单体,采用紫外光（UV）接枝的方法对棉织物进行接枝改性,采用傅立叶红外光谱仪（FTIR）、有机元素分析仪和热重分析（TGA）对接枝样品进行表征,研究了单体浓度、光引发剂浓度、光照时间等因素对接枝率的影响。红外光谱分析和有机元素分析证明AM接枝到棉织物上。接枝率随着接枝单体浓度和光照时间的增加而增大,并随着引发剂二苯甲酮（BP）的浓度的增加先增大后减小;AM浓度为20wt%,BP浓度为3wt%,接枝反应40min,接枝率达到24.05%。接枝改性的棉织物,亲水性得到提高,接枝棉织物的亲水性随接枝率的增加而增大。     

玉米淀粉丙烯酸接枝共聚反应影响因素研究

淀粉接枝共聚物是一类新型功能材料,研究了单体与淀粉配比、单体中和度、反应温度、交联剂浓度、引发剂浓度对玉米淀粉与丙烯酸在水溶液中接枝共聚反应的影响,通过正交实验得到最佳工艺条件为单体与淀粉配比8:1,单体中和度70%,反应温度60℃,交联剂浓度0.1%,引发剂浓度2%。聚合物在自来水中最大吸液倍率为378 g/g。     

引发剂对淀粉接枝丙烯酸丁酯的影响的研究

采用新的还原氧化引发体系引发玉米淀粉接枝丙烯酸丁酯单体，获得了接枝淀粉浆料，利用扫描电镜、红外光谱等测试方法对其结构进行了研究与表征，本文还对淀粉接枝共聚的工艺进行了探索研究，结果表明：丙烯酸丁酯成功的接枝到淀粉颗粒上，接枝共聚的最佳工艺为反应温度40℃，反应时间3h，淀粉／丙烯酸丁酯的质量比为2：1，引发剂的加入量为每10g淀粉中30ml（氧化剂为4mmol／L，还原剂为2mmol／L）。     

壳聚糖改性两性聚丙烯酰胺增强剂的制备及应用

用壳聚糖与甲基丙烯酰氧乙基三甲基氯化铵（DMC）、丙烯酰胺（AM）、马来酸（MA）接枝共聚得到壳聚糖改性两性聚丙烯酰胺增强剂（CAmPAM）,研究了单体选择、反应浓度、温度等影响因素对聚合反应的影响。壳聚糖改性两性聚丙烯酰胺增强剂的最佳合成条件为：m（CS）：m（DMC）：m（AM）：m（MA）=1：5：9：1,反应温度80℃,硝酸钸铵的浓度为0．4mmol／L,过硫酸铵／亚硫酸氢钠／引发剂A的用量各0．075％,壳聚糖用乙酸溶解20min,接枝共聚反应4h,pH开始时2．0,结束时3．2,反应单体浓度为15％。     

接枝共聚物型聚丙烯酰胺助留助滤剂的合成及性能研究

以丙烯酰胺(AM)、甲基丙烯酰氧乙基三甲基氯化铵(DMC)以及无机化合物为原料,采用水溶液接枝共聚研制了相对分子质量适宜的无机化合物接枝AM共聚物型聚丙烯酰胺(I-PAM)助留助滤剂,并对其性能作了研究,结果发现:该助留助滤剂可与K350相媲美.最适宜的合成条件为:无机物与有机物单体组成比为15:85,AM与DMC重量比为60:40,引发剂用量为混合单体的0.08%,链转移剂用量为混合单体的4.5%,反应温度为30～40℃.     

淀粉基高吸水性树脂的制备及性能研究

以交联氧化淀粉为基体,丙烯酸(AA)和丙烯酰胺(AM)为接枝单体,过硫酸钾和亚硫酸氢钠为引发剂,采用水溶液聚合法制备交联氧化淀粉基丙烯酸-丙烯酰胺高吸水性树脂,研究淀粉用量、单体质量比、引发剂用量、淀粉氧化度与交联度对高吸水树脂吸水性能的影响。结果表明,较佳工艺条件是:淀粉基体用量为25%,单体质量比为AA∶AM=5∶1,引发剂用量为1.2%,淀粉溶胀度与羧基含量之比为48∶1,反应温度50℃,反应时间2h。此工艺条件制得的高吸水性树脂吸去离子水倍率2216g/g,吸1%NaCL溶液倍率170g/g,吸1%MgSO_4溶液倍率53g/g,吸1%CaCL_2溶液倍率15g/g,吸1%ALCL_3溶液倍率8g/g。     

Graft Copolymerization Onto Starch. 3: Grafting of Acrylamide Using Ceric Ion Initiation and Preparation of Its Hydrogels

The grafting of acrylamide (AM) onto maize starch in aqueous medium initiated by ceric ammonium nitrate (CAN) has been studied gravimetrically under nitrogen atmosphere. The effect of concentration of monomer and initiator, polymerization time and reaction temperature has been studied in terms of efficiency of grafting (%GE) and percentage Add-on (%Add-on). The %GE was found to decrease with increase in monomer concentration, but the reverse trend was obtained on increasing the polymerization time and temperature. The maximum %GE was obtained at 45°C when polymerization was carried out for 180 min using [CAN] = 0.004 mol/L and [AM] = 0.141 mol/L in 100 mL of distilled water with 2 g of starch. These graft copolymers were characterized by IR spectroscopy and thermogravimetric analysis. The graft copolymers showed enhanced thermal stability than pure starch. Hydrogels were prepared by grafting AM onto gelatinized maize starch followed by saponification of these graft copolymers with NaOH. The maximum water absorption obtained was 170 g/g.     

香蕉皮接枝丙烯酸制备吸水树脂的工艺探讨

研究以天然易得、纤维素含量高的香蕉皮粉为接枝骨架,丙烯酸为接枝单体通过自由基接枝共聚在水溶液中合成吸水树脂的工艺,实现香蕉皮的废物利用,并对树脂生产工艺进行优化。考察了丙烯酸中和度、体系总水量、香蕉皮粉用量、引发剂用量、交联剂用量等条件对树脂在蒸馏水和0.9%Na Cl溶液中吸水性的影响,同时探讨了亚硫酸钠对聚合反应时间和温度的影响及扩大反应体系后树脂的温度变化。结果表明,各试剂用量对树脂吸水性都有不同程度的影响,在最优工艺下形成的树脂对蒸馏水和生理盐水的吸水量分别为161.05 g/g和46.03 g/g,亚硫酸钠可以缩短反应开始时间降低引发温度,大型反应可通过自身反应放热完成接枝共聚。该实验简化了生产工艺,降低了生产要求,有良好的应用前景。     

反相乳液聚合制备阳离子改性接枝淀粉

本实验以淀粉、丙烯酰胺、阳离子单体(二甲基二烯丙基氯化铵)为原料,采用过硫酸铵-尿素氧化还原引发体系,以油酸失水山梨醇酯为乳化剂,通过反相乳液聚合技术,合成阳离子改性淀粉接枝共聚物.分析讨论了单体配比、乳化剂用量、引发剂用量及油水体积比等合成条件对共聚物性能的影响,并采用正交实验方法对合成条件进行了优化.     

Synthesis,characterization and swelling behaviour of superabsorbent polymers from cassava starch‐graft‐poly(acrylamide)

Superabsorbent polymers (SAPs) were prepared from cassava starch by graft copolymerization of acrylamide on to starch using ceric ammonium nitrate (CAN) as free radical initiator, followed by alkali saponification. The reaction parameters such as concentration of acrylamide, concentration of CAN, temperature, and duration of polymerization reaction were optimized for maximum water absorbency using a 4‐factor 3‐level Box‐Behnken design. The highest values of percentage grafting and absorbency obtained were 174.8% and 425.2 g/g, respectively. The polymers were characterized by determination of grafting efficiency, N‐content, acrylamide content, FTIR analysis, SEM and XRD analyses. Thermogravimetric analysis (TG) showed that the SAP has higher thermal stability. The rate of water absorbency and the swelling behaviour of the SAP under different conditions of pH, and different salts were determined. The de‐swelling pattern of the hydrogels over different time durations was also determined.     

反相乳液聚合制备阳离子改性接枝淀粉

本实验以淀粉、丙烯酰胺、阳离子单体(二甲基二烯丙基氯化铵)为原料,采用过硫酸铵--尿素氧化还原引发体系,以油酸失水山梨醇酯为乳化剂,通过反相乳液聚合技术,合成阳离子改性淀粉接枝共聚物.分析讨论了单体配比、乳化剂用量、引发剂用量及油水体积比等合成条件对共聚物性能的影响,并采用正交实验方法对合成条件进行了优化.     

A Novel Copolymer: Starch‐g‐Polyvinylpyrrolidone

In this study, graft copolymerization of N‐vinylpyrrolidone (N‐VP) onto starch was carried out in an aqueous medium using azobisisobutyronitrile (AIBN) as initiator. The variables affecting the graft copolymerization, such as monomer and initiator concentrations, reaction time and temperature, were thoroughly examined. In general, grafting of N‐vinylpyrrolidone onto starch increased with the increase in time and monomer concentration up to a certain value and then leveled off. Similarly, increase both in initiator concentration and temperature first favored and than impeded the grafting reaction. Optimum conditions established for grafting were as follows: N‐VP = 0.7 M, AIBN = 1.5×10^‐3 M, T = 70°C and t = 5 h. Structural changes of the grafted starch were followed by FTIR, intrinsic viscosity and water absorption capacity studies.     

马铃薯淀粉与醋酸乙烯酯接枝聚合影响因素的研究

以马铃薯淀粉为接枝骨架,过硫酸铵为引发剂,醋酸乙烯酯(VAc)为接枝单体进行接枝共聚。考察了不同引发剂浓度、反应温度、反应时间、单体配比、淀粉浓度对单体转化率、接枝率及接枝效率的影响,确定最佳工艺条件为:引发剂浓度18 mmol/L,反应温度60℃,反应时间3.5 h,单体配比2.5:1,淀粉浓度5%。并通过扫描电镜,X射线衍射,傅里叶红外光谱对淀粉接枝共聚物进行分析,结果表明:淀粉接枝共聚后,淀粉的微观形貌已经改变,结晶度降低且醋酸乙烯酯成功接枝在马铃薯淀粉上。     

以氮为中心的交联接枝共聚淀粉黄原酸盐制备工艺优化及产物表征

以可溶淀粉和原乙酸三甲酯进行缩醛反应生成淀粉环酯,在氨水中交联、接枝共聚、磺化合成出以氮为中心的交联接枝共聚淀粉黄原酸盐(dithioamino starch xanthogenate,DSX)。通过正交试验设计方法优化制备条件,结果表明:原料淀粉10g、交联剂(环氧氯丙烷)1.77g、引发剂(过硫酸铵)0.053g、接枝单体(丙烯酰胺)3.37g和二硫化碳6.30g,合成的产物(DSX)对模拟废水中Cu2+的去除率达到98.5%。采用红外图谱、元素分析、核磁、热分析、扫描电镜等多种手段对产物进行表征。     

Synergetically Acting new Flocculants on the Basis of Starch‐graft‐Poly(acrylamide)‐co‐Sodium Xanthate

A synergetically acting new flocculant on the basis of starch‐graft‐poly(acrylamide)‐co‐sodium xanthate (CSAX) was synthesized by grafting copolymerization of crosslinked corn starch, acrylamide (AM), and sodium xanthate, using epichlorohydrin (EPI) as cross‐linking agent and ceric ammonium nitrate (CAN) as polymerization initiator in aqueous solution. The effects of some factors, such as crosslinker, initiator, AM, NaOH, on the %Tr (turbidity removal rate), %Trd (turbidity removal rate of a water sample which has both turbidity and heavy metal ions %Hr (heavy metal ion removal rate) and %Hrd (heavy metal ions removal rate of water which has both heavy metal ions and turbidity), are investigated. As proven by FTIR and elemental analysis, the CSAX can be successfully synthesized and can remove both turbidity‐causing substances and heavy metal ions from aqueous solutions. Under optimum synthesis conditions CSAX exhibits excellent performance, i.e. %Tr = 98%, %Trd = 98.4%, %Hrd = 99% and %Hr = 91.6%, respectively.     

低取代度阳离子淀粉-丙烯酰胺接枝共聚物的制备及应用

以低取代度的阳离子淀粉为原料,硝酸铈铵为引发剂,制备了低取代度阳离子淀粉-丙烯酰胺接枝共聚物。研究了丙烯酰胺与阳离子淀粉质量比、反应温度、反应时间和引发剂浓度对接枝率和接枝效率的影响。结果表明:接枝率和接枝效率最高的条件为:m(丙烯酰胺)∶m(阳离子淀粉)=2.5∶1,反应温度为55℃,反应时间为3 h,c(引发剂)=2 mmol/L。将合成的聚合物用于纸张增强,当低取代度阳离子淀粉-丙烯酰胺接枝共聚物的用量为1.0%时,对纸张的增强效果最好,可使纸张抗张指数增加23.0%,撕裂指数增加12.7%,耐破指数增加63.7%,耐折度增加115.1%。