焦磷酸络锰三价离子引发淀粉-丙烯酰胺的接枝共聚合

将带有极性基团的乙烯类单体通过化学接枝到淀粉或纤维素之类的天然多糖上,可作为絮凝剂、脱除剂和粘接剂^[1～3],近来已发展为高吸水性材料和石油分离剂^[4]。用Ce⁴⁺引发乙烯类单体接枝到淀粉和纤维素类已有报道^[5]。Rayonier用Mn³⁺的焦磷酸盐络合物引发接枝乙烯类单体至纤维素及其衍生物上^[6];Cenita等用Mn³⁺引发MMA、AN接枝淀粉^[7]。本文以焦磷酸络锰离子(Mn³⁺)作引发剂、丙烯酰胺(AM)为单体、淀粉为接枝基体进行接枝共聚,这一工作目前在国内外尚未见报道。     

Graft copolymerization of acrylamide onto carboxymethyl starch

Water absorption resins of carboxymethyl starch graft acrylamide (CMS-g-AM) were synthesized by copolymerization based on a free radical reaction. At first, CMS was prepared with starch and chloroacetic acid in an alkali-methanol media. Then, AM was grafted onto CMS by using ceric ammonium nitrate as an initiator. The resulting graft products were identified by infrared spectra. The effects of the preparation conditions on the substituent degree (SD) of starch and the water absorption capacities of CMS-g-AM were investigated. The results showed that SD of starch first increased remarkably and then decreased gradually with increased addition of sodium hydroxide, and the water absorption capacity of CMS-g-AM depended greatly on the SD of CMS and its maximum with 0.75 of SD of starch was 350 g/g.     

PAAM高吸水树脂反相悬浮聚合

采用反相悬浮聚合法,通过部分中和丙烯酸与丙烯酰胺共聚制备了聚(丙烯酸-丙烯酰胺)(PAAM)高吸水树脂,讨论了聚合过程主要影响因素对其吸液性能的影响,并对其进行了FTIR、TGA测试,得到最佳的合成工艺配方:单体质量浓度为30%,中和度N为75%,丙烯酸与丙烯酰胺的摩尔比为7∶3,交联剂、引发剂和分散剂质量浓度分别为0.065%、0.7%和0.5%(相对于单体总质量),单体溶液的滴加速度为2～3mL/min,聚合温度和时间分别为70℃和1.5h。此时在蒸馏水、0.9%NaCl溶液%(wt)中最大吸水倍率分别为Qw=1300g/g、Qs=93g/g(Qw为蒸馏水中吸水倍率,Qs为0.9%NaCl溶液中的吸水倍率,下同),树脂在320℃之前都是比较稳定的,可以适应较高的使用温度。     

钻井液用交联-接枝淀粉的制备及性能

以N,N′-亚甲基双丙烯酰胺为交联剂,过硫酸铵为引发剂,采用“溶剂法”工艺合成了高粘度抗剪切丙烯酸钠接枝淀粉(St),考察了单体、引发剂和交联剂用量、丙烯酸中和度、反应时间及反应温度对合成交联丙烯酸钠接枝淀粉糊液粘度的影响。 结果表明,其优化反应条件为：m(淀粉)∶m(丙烯酸）=1∶1.5,乙醇质量分数为80%,过硫酸铵的用量为单体总质量的1%,交联剂为单体总质量的0.6%,反应时间2.5 h,反应温度为55 ℃,丙烯酸中和度为70%。 该交联接枝淀粉糊液具有良好的触变性,在4%盐水泥浆中的添加量为14.0 g/L时,表观粘度为26.0 mPa·s,滤失量为7.2 mL;在饱和盐水泥浆中添加量为23.5 g/L时,表观粘度为54.5 mPa·s,滤失量为3.1 mL;在80 ℃高温下老化16 h其表观粘度及滤失量等性能基本保持不变,表现出良好的增粘、降失水作用和抗盐、抗老化性能。     

木薯淀粉与丙烯酸接枝共聚制备淀粉增稠剂

用过硫酸盐 (过硫酸纳、钾或胺盐 )氧化法使木薯淀粉与丙烯酸接枝共聚。探索到最佳反应温度 55℃ ,反应时间 3h ,单体用量 3.1 2 5mol/L ,引发剂浓度 3.5mmol/L ,接枝百分率可达 70 %以上。产品用作淀粉糊的增稠起到明显的效果     

Modification on liquid retention property of cassava starch by radiation grafting with acrylonitrile. I. Effect of γ-irradiation on grafting parameters

Radiation modification on liquid retention properties of native cassava starch, gelatinized at 85°C, by graft copolymerization with acrylonitrile was carried out by mutual irradiation to gamma-rays. A thin aluminum foil was used to cover the inner wall of the reaction vessel, so that the homopolymer concentration was reduced to be less than 1.0% with a distilled water retention value of 665 g/g of the dry weight of the saponified grafted product. Confirmation of graft copolymerization and saponification reactions was made by the infrared spectrophotometric technique. The combined effect of radiation parameters in terms of an irradiation time and a dose rate to the total dose on the extent of the grafting reaction expressed in terms of grafting parameters which directly influenced liquid retention values was evaluated in conjunction with statistical analysis.     

Graft copolymerization onto cellulose-based filter paper and its further development as silver nanoparticles loaded antibacterial food-packaging material

The present work describes ceric ammonium nitrate (CAN) initiated graft copolymerization of acrylamide onto cellulose-based filter paper followed by entrapment of silver nanoparticles. The copolymerization was carried out in aqueous solution, containing 2 M acrylamide monomer and 16 mM N,N’-methylene bisacrylamide (MB) crosslinker. The optimum initiation time and grafting reaction temperature were found to be 15 min and 30 °C, respectively. The silver nanoparticles were loaded into grafted filter paper by equilibration in silver nitrate solution followed by citrate reduction. The formation of silver nanoparticles has been confirmed by TEM and SAED analysis. The novel nano silver loaded filter paper has been investigated for its antimicrobial properties against E.coli. This newly developed material shows strong antibacterial property and thus offers its candidature for possible use as antibacterial food-packaging material.     

氧化淀粉基高吸水性树脂的制备及表征

以过硫酸铵为引发剂,N,N’-亚甲基双丙烯酰胺为交联剂,制备氧化淀粉―丙烯酸―丙烯酰胺高吸水性树脂,并采用红外光谱、X射线衍射等手段对产品的结构进行表征。通过单因素实验优化其制备工艺,最佳工艺条件为:氧化淀粉基体用量为50%,丙烯酸/丙烯酰胺质量比为4∶1,丙烯酸中和度为70%,引发剂过硫酸铵用量为0.5%,交联剂N,N’-亚甲基双丙烯酸胺用量为0.15%,反应温度为80℃,反应时间为3 h。此条件下,氧化淀粉基高吸水性树脂的吸水率达到972.4 g/g。     

丙烯酸与丙烯酰胺共聚制备高吸水性树脂

采用溶液聚合法,以N,N’-亚甲基双丙烯酰胺（NMBA）为交联剂,过硫酸钾（KPS）为引发剂合成了高吸水性树脂聚（丙烯酸-丙烯酰胺）（P（AA—AM））,研究了单体配比、丙烯酸中和度、引发剂及交联剂用量、反应温度对树脂在去离子水和0．9％盐水中吸水率的影响．最佳条件下制备的树脂在去离子水中吸水率为750g·g^-1,在0．9％盐水中吸水率为85g·g^-1．     

两性淀粉接枝共聚物的就地制备和性质

糊化淀粉经阳离子试剂醚化后再直接与丙烯酸钠(AA-Na)/丙烯酰胺(AM)接枝共聚,制得具有两性的淀粉接枝共聚物。并对淀粉的阳离子试剂醚化、淀粉与AA-Na/AM接枝共聚的接枝率、单体转化率、接枝效率及淀粉的糊化方式对产物性能的影响进行了研究。为工厂就地生产和应用两性淀粉接枝共聚物提供技术依据。     

丙烯酰胺与N,N′-亚甲基双丙烯酰胺的共聚反应研究

本文利用凝胶模量测定法、气相色谱法和紫外光谱法对丙烯酰胺与N,N’-亚甲基双丙烯酰胺水溶液共聚反应进行了研究,证实了N,N’-亚甲基双丙烯酰胺的反应活性明显大于丙烯酰胺的反应活性。用气相色谱法测得单体的竞聚率分别为r_(AM)=0.117,,r_(Bis)=5.756;用紫外光谱法研究了聚合反应中氧化还原引发剂浓度和反应温度对聚合反应速率的影响,得出共聚反应速率方程中,氧化剂的方次为0.66,还原剂浓度的方次为0.55,并求出共聚反应表现活化能为37.1KJ/mol。     

丙烯酰胺与N,N′-亚甲基双丙烯酰胺的共聚反应研究

 本文利用凝胶模量测定法、气相色谱法和紫外光谱法对丙烯酰胺与N,N’-亚甲基双丙烯酰胺水溶液共聚反应进行了研究,证实了N,N’-亚甲基双丙烯酰胺的反应活性明显大于丙烯酰胺的反应活性。用气相色谱法测得单体的竞聚率分别为r_AM=0.117,,r_Bis=5.756;用紫外光谱法研究了聚合反应中氧化还原引发剂浓度和反应温度对聚合反应速率的影响,得出共聚反应速率方程中,氧化剂的方次为0.66,还原剂浓度的方次为0.55,并求出共聚反应表现活化能为37.1KJ/mol。     

Superabsorbent nanocomposite and its properties

Starch-g-poly (AM-AMPS)/illite superabsorbent nanocomposite was synthesized by grafting copolymerization reaction of starch, acrylamide(AM) and 2-acrylamido-2- methyl propane sulfonic acid (APMS) in the presence of illite micropowder in deionized aqueous solution. The influence factors on water absorbency of the superabsorbent nanocoposite was optimized by single factor experiment. The synthesized superabsorbent nanocomposite exhibited the maximum water absorbency of 1320?g H₂O/g in deionized water and 142?g H₂O/g in 0.9?wt% sodium chloride (NaCl) solution. FTIR spectra confirmed that the grafting copolymerization between -OH groups on starch and monomers generated during the reaction. XRD analysis confirmed that crystal interlayer of illite was pulled open to 3.61?nm. TEM showed that illite slice layer randomly dispersed in the matrix of superabsorbent nanocomposite. The superabsorbent nanocomposite had a better thermal stability the corresponding superabsorbent material without illite by TGA and DSC analysis. The superabsorbent nanocomposite with excellent water absorbency and water retention could be especially useful in industry, agricultural, horticultural applications.     

蔗渣基重金属离子吸附剂的制备

采用甘蔗残渣、丙烯酸(AA)、丙烯酰胺(AM)、甲基丙烯酰氧乙基三甲基氯化铵(MAETAC)为原料,通过接枝共聚反应制备出蔗渣基重金属离子吸附剂,对制备该吸附剂的影响因子如活化时间、蔗渣和单体的配比、引发剂用量、温度和时间等条件进行了分析研究,通过正交试验得到了合成吸附剂的优化工艺条件.优化条件下合成的蔗渣基吸附剂对Cu2+的吸附容量达到58.53mg/g,是蔗渣原料的12倍.     

铬酸引发丙烯酸正丁酯与淀粉接枝共聚反应

作为淀粉改性方法之一 ,不饱和酸及其酯与淀粉接枝共聚反应是一个较新的研究领域 ,其中以 Ce4 +离子作为引发剂的较多[1,2 ] ,也有用Mn3+-H2 SO4 体系 [3]和 Mn[( H2 P2 O7) 3]3-引发体系的[4 ] 。铬酸是一种具有强氧化性的强酸 ,虽然它单独存在时并不引发乙烯类单体的聚合 ,有报道[5] 铬酸可以引发丙烯腈与苎麻纤维素接枝共聚 ,淀粉和纤维素同属于碳水化合物。本文对铬酸引发丙烯酸正丁酯与淀粉接枝共聚反应进行了研究 ,考察了反应条件对接枝反应的影响。1　实验部分1 .1　原料可溶性淀粉 (北京奥特生物技术责任有限公司 ) ,丙烯酸正丁…     

淀粉与丙烯酰胺的接枝共聚

本文以木薯淀粉为骨架,以丙烯酰胺为单体,进行淀粉—丙烯酰胺接枝共聚的研究。对接枝共聚过程中引发剂浓度、单体浓度、反应温度、反应时间、介质酸浓度及淀粉糊化温度等因素的影响进行了讨论,寻找接枝共聚的最佳反应条件。     

离子液体中AM/AMPS/N8AM三元共聚物的合成及溶液性能

以丙烯酰胺(AM)和2-丙烯酰胺基-2-甲基丙磺酸(AMPS)为亲水单体, 以N-辛基丙烯酰胺(N8AM)为疏水单体, 在离子液体[bmim]BF4中实现了疏水缔合丙烯酰胺三元共聚物的合成.     

Preparation of hydrogel from green polymer

A new method was used for the production of hydrogels from green polymer with a higher swelling ratio. These hydrogels were synthesized first by graft copolymerization between acrylamide (AM) and poly(vinyl alcohol) (PVA) with alkaline or kraft lignin (AM‐PVA‐g‐lignin) and then by mixing with acrylamide monomer. The kraft and alkaline lignins were isolated from pulping liquor and characterized using UV and FT‐IR spectroscopy, and the formed hydrogels were characterized using FT‐IR spectroscopy and scanning electron microscopy (SEM). Compared with kraft lignin hydrogel, the alkaline lignin hydrogel had very high swelling ratios and slower water uptake and deswelling rates attributed to its compatible network structure. The hydrogels formed were used also to study the influence of sodium chloride on the absorption capacity at room temperature and swelling ratios at different temperatures. Copyright © 2004 John Wiley & Sons, Ltd.     

(2-甲基丙烯酰氧乙基)三甲基氯化铵-丙烯酰胺双水相共聚合

将(2-甲基丙烯酰氧乙基)三甲基氯化铵(DMMC)与丙烯酰胺(AM)在聚乙二醇(PEG)水溶液中进行双水相共聚合(ATPC),并与DMMC/AM均相水溶液共聚合(HASC)进行比较.在均相水溶液共聚合体系中得到了DMMC/AM共聚体系的竞聚率分别为rDMMC=1.77、rAM=0.32,并给出了竞聚率的95%,99%联合置信区域.比较了两种共聚合体系的转化率-时间曲线和共聚组成,表明双水相共聚合体系初期反应速率高于均相水溶液共聚合体系,但最终转化率相似;两种共聚合体系得到的共聚物组成有较大差别.测得了DMMC、AM以及DMMC-AM共聚物(CPAM)在65℃、反应条件下的相分配系数为K1=0.035、K2=0.125和Kp=0.011.结合双水相聚合的本质以及单体和共聚物在两相的分配系数,提出了一个计算双水相共聚组成的新方法,用该方法计算的双水相共聚合体系的共聚组成与实验点吻合较好.     

Grafting onto Gelatin. II. Graft Copolymerization of Ethyl Acrylate and Methyl Methacrylate onto Gelatin in the Presence of Ce4+ as Redox Initiator

In order to initiate a comprehensive study of graft copolymerization of vinyl monomers onto soluble protein-gelatin, we have studied grafting of ethyl acrylate (EA) and methyl methacrylate (MMA) onto gelatin using eerie ammonium nitrate (CAN) and eerie ammonium sulfate (CAS) as the redox initiator in an aqueous medium. A small amount of mineral acid (HNO₃ with CAN and H2SO4 with CAS) was found to catalyze the graft copolymerization. Graft copolymerization reactions were carried out at different temperatures. Maximum grafting occurred at 65°C both with EA and MMA. Percentage grafting has been determined as function of 1) concentration of monomer (EA and MMA), 2) concentration of initiator (CAN and CAS), 3) concentration of acid (HNO3 and H2SO4), 4) time, and 5) temperature.