Graft Polymerization of Acrylic Acid and Acrylamide onto BOPET Corona Films

The graft polymerization of acrylic acid(A) and acrylamide(B) was carried out onto bi-oriented polyester BOPET corona film.The influence of monomer concentration,reducer concentration and reaction time on the graft polymerization was investigated.The surface tension of the films increased with an increase of monomer concentration,till the concentration of monomer A reached 1.5×10^(-2)g/mL and the concentration of monomer B reached 4.0×10^(-2)g/mL.The surface tension of the films reached a maximum value at 7×10^(-4)M of reducer concentration and subsequently decreased with further increase in reducer concentration.The surface tension of the films increased with the increase of the reaction time apparently within 50min.The grafted corona BOPET films were characterized with IR and XPS.The presence of graft on the film surface was confirmed.The attenuation experiments on grafted corona BOPET films in air at 50℃ and in water were carried out to investigate the persistence of graft polymerization of acrylic acid and arylamide onto BOPET corona films.

Preparation of superabsorbent by graft copolymerization of acrylic acid onto corn starch using K_2S_2O_8 and rare earths as initiators

K2S2O8 and rare earths(RE)were used as initiators to prepare superabsorbents by graft copolymerization of acrylic acid(AA)onto corn starch.The effects of monomer concentration,initiator K2S2O8 concentration,cross-linker concentration,reaction temperature and the concentration ratio of RE and K2S2O8 on the graft copolymerization were studied in terms of the water absorption capacity of superabsorbents.Results indicate that the optimum conditions obtained for the grafting of AA onto 5g starch are as follows:AA of 75.773 g/L,K2S2O8 of 0.437 g/L,RE of 0.874 g/L,cross-linker of 0.381 g/L and temperature of 70 ℃.The maximum water absorption capacity obtained is 740 g/g.The new method of graft polymerization is easily proceeded and controlled.The graft copolymers were characterized by infra-red spectroscopy,scanning electron microscopy and TG.Results characterized by IR and SEM give strong evidence for grafting of AA onto corn starch,and those characterized by TG reveal that the grafting of AA improves the thermostability of corn starch.

Reactivity Ratios of Diethyldiallylammonium Chloride with Acrylamide or Acrylic Acid

The compositions of copolymers of diethyldiallylammonium chloride （DEDAAC） with acrylamide （AM）, acrylic acid （AA） or sodium acrylic acid （NaAA） at low conversion were determined by elemental analysis, and the reactivity ratios of monomers in copolymerization were obtained by Kelen-Tudos method. The results showed that the reactivity ratios rDE and rAM are 0.31 and 5.27 for DEDAAC with AM, rDE and rAA are 0.28 and 5.15 for DEDAAC with AA, and roe and rNsAA are 0.40 and 3.97 for DEDAAC with NaAA, respectively. The copolymerizations for DEDAAC with AM, AA or NaAA are non-ideal copolymerization and the products are random copolymers.

Radiation Induced Grafting of Acrylic Acid onto Viscose Rayon Fabrics and Its After-Effects

Radiation induced grafting of various polymers with different monomers proved to be an attractive means to modify the physical or chemical properties of polymeric materials or textile fabrics. In the present work, radiation induced grafting of viscose rayon fabrics, consisting mainly of cellulose fibers, with acrylic acid monomer has been carried out. The grafting yields have been thoroughly studied as a function of different applied experimental parameters. The impact of the graft yield on the physical properties of the fabrics such as tensile strength, elongation, swelling, moisture absorption, crease recovery angle and also the dyeing properties of the fabrics has been studied. The effect of increasing the contact time of the fabric and monomer solution, at room temperature, after stopping irradiation has been studied in detail as well as the effect of temperature on the irradiated samples also after stopping irradiation. The best grafting yield was obtained on irradiating viscose rayon fabric in methanol-water solvent containing acrylic acid monomer, at a dose 20 kGys, then heating for 7 hours at 80℃ and finally keeping the samples at room temperature for about 20 hours. That treatment significantly increased the final graft yield.

Studies on the Graft Copolymerization of Methyl Acrylate and Ethyl Acrylate onto Corn Starch Using Potassium Persulfate-Sodium Thiosulphatc as Initiation System

Grafting copolymerizations of methyl acrylate(MA) and ethyl acrylate(EA) onto corn starch, respectively, initiated by potassium persulfate-sodium thiosulphate (KPS-STS) redox system, were studied. The structures of poly(MA)-g-starch and poly(EA)-g-starch were characterized by IR, SEM and X-ray diffraction. Experimental results show that KPS-STS is an efficient initiation system for grafting of MA and EA onto corn starch. The maximum percent grafting was obtained at [KPS] of 6.0× 10~3 mol/L, [STS] of 1.8× 10 5 mol/L, [M] of 6. 0× 101 mol/L, S:L=4:100 at 40℃ for 6 h. The reactivity order is MA>EA.

The Optimized Synthesis of Starch-g-Lactic Acid Copolymer with High Grafting Degree Catalyzed by Sulfuric Acid

The starch-g-lactic acid copolymer was synthesized with catalysis of sulfuric acid by onestep process, and the structure of starch-g-lactic acid copolymer was characterized by means of IR, 13C-NMR, HMBC, XRD, and SEM. The experimental results show that the maximum grafting degree of starch can reach 75% when the starch-g-lactic acid copolymer is activated at 80 ℃ for 2 h and reacted with lactic acid at 90 ℃ for 4 h in vacuum.

The Optimization of Synthesizing Graft Copolymer of Starch with Vinyl Monomers

The graft copolymerization of acrylamide （ AM ） / acrylic acid （ AA ） onto starch （ St- g-pAA and St-g-p（AA-co-AM） ） was carried out using an orthngonal test method. The combined effects of different reaction conditions on the water absorbency of the graft copolymers were optimized through mathematical statistical methods of range and square variance analysis. The maximum water absorbency was obtained when the ratio of dried starch to distilled water was 1 ： 8 （ w/w ）, the ratio of starch to monomer 1 ： 6 （ w/w ）, the initiator concentration 4.40 × 10^-3 mol/L, the crosslinker concentration 10.86 × 10^-2 mol/L, and the basicity to AA 0. 70（ mol/mol ）. Both the graft copolymers have an excellent water absorption capacity in distilled water aact in 0. 9wt% NaCl solution. It was also found that in distilled water the water absorbency of St-g-pAA was higher than that of St-g-p（ AA-co-AM） , while in 0.9wt% NaCl solution, the situation was just the reverse. The correlation between the water absorbeacy anct the nature of the solution anct the properties of the copolymers, which is related to the properties of the monomers, was discussed. The grafting of AA ancl AM onto starch was confirmed by the IR spectra of St-g-pAA and St-g-p（ AA-co-AM）.

Radiation Induced Grafting of Viscose Rayon Fabrics with Some Acrylic Acid Derivatives and Styrene

Radiation induced grafting of viscose rayon fabrics, consisting mainly of cellulose fibers, with some acrylic acid derivatives, namely methyl acrylate, acrylamide and acrylonitrile, and also styrene, has been studied. The resultant graft yields have been determined as a function of the applied different experimental parameters. The impact of the graft yields on the physicochemical properties of viscose rayon fabrics such as swelling, moisture absorption, tensile strength, elongation at break, crease recovery angle and also dyeing ability of the grafted fabrics, has been also studied.

RADICAL GRAFTING REACTIONS ONTO STARCH AND OTHER WATER-SOLUBLE COPOLYMERS IN ISOLATED GEL DROPLETS

A novel radical grafting copolymerization process has been designed for water-soluble polymers which avoids the problems of conducting grafting reactions in highly viscous polymerization media. A variety of water-soluble graft copolymers having starch or dextran as the backbone chain with grafted side chains of polyacrylamide (—AM—), poly (acrylic acid ) (—AA—), poly (acrylamide-co-acrylic acid) (—AM—NH_4AA—) or poly ( acrylamide-co-2-acryiamido-2-methyl-l-propanesulphinic acid) (—AM—AMPS—) have been synthesized in gel droplets using aceric sulphate redox initiator, and their properties compared. The reaction conditions were optimized taking into account reaction kinetic data and the observed properties of the products produced under different reaction conditions. The effects of the ratios of [backbone]/[graft monomer], [ AM]/[ AA]/[AMPS] , [Ce^(4+)]/[ S_2O_8=] and pH value on the reaction rate , conversion, grafting degree, grafted chain length and the product molecular weight have been investigated.

STUDY ON THE STARCH GRAFTED ACRYLATE MONOMERS AND ITS COMPATIBILITY FOR THE BLEND SYSTEM OF STARCH AND POLYETHYLENE

研究采用高温和剪切力的作用直接引发淀粉与丙烯酸酯单体的接枝共聚合反应．讨论了各种反应条件对接枝反应的影响，并进一步研究了接枝物在淀粉聚乙烯共混体系中的增容作用．实验结果表明，高温和剪切作用力可以引发淀粉与丙烯酸酯单体的接枝共聚合反应。接枝物作为增容剂，对淀粉聚乙烯共混体系的力学性能和流变学性能均有所改善．

Studies on Graft Copolymerization of Acrylic Acid onto Ramie Fibers with Chromic Acid Initiation System

The graft copolymerization of acrylic acid (AA) with unswollen and swollen ramie fibers using chromic acid (H 2CrO 4) as the initiator has been studied in the presence of air. The effects of initiator concentration, monomer concentration, perchloric acid (HClO 4) concentration, time of polymerization, reaction temperature, and amount of ramie fibers on the graft percentage have been found out. The graft copolymer was characterized by IR spectra, scanning electron microscopy(SEM), differential thermal analysis (DTA), and thermogravimertric analysis (TGA).

STUDY ON THE REACTION MECHANISM OF RADIATION GRAFTING OF ACRYLIC ACID ONTO POLYSTYRENE

It is difficult to find a solvent of grafting copolymer of acrylic acid onto polystyrene, thus it is not easy to analyse its structure by ordinary methods. Until now, many scientists considered that grafting reaction occurs on the main chain of polystyrene. In this work, the radiation grafting mechanism is studied with solid NMR and infrared. We have found that the grafting position is on the meso position of phenyl ring of polystyrene when the solvent is methanol and the matrix is polystyrene and a preirradiation method is used. It

木薯淀粉-丙烯酰胺接枝共聚物的结构与性能

为消除传统人造板的甲醛释放对人体健康和环境造成的危害,将木薯淀粉(CS)降解后与丙烯酰胺(AM)接枝共聚,制备木薯淀粉-丙烯酰胺接枝共聚物(CS-AAGC)胶黏剂,并对其外观、黏度、固含量等基本性能进行测定。通过傅里叶变换红外光谱(FT-IR)、核磁共振碳谱(13C NMR)及X射线光电子能谱(XPS)对其结构进行分析,采用差式扫描量热分析(DSC)及扫描电镜(SEM)分析其固化性能,探究木薯淀粉与丙烯酰胺(AM)的物质的量比对木薯淀粉-丙烯酰胺接枝共聚物胶黏剂胶合强度的影响。结果表明:合成的木薯淀粉-丙烯酰胺接枝共聚物胶黏剂外观为乳白色均一液体,随着丙烯酰胺添加量的增加,共聚物的黏度也随之增加;丙烯酰胺上的双键与淀粉中的羟基发生了反应;当n(淀粉基本单元)∶n(AM)=1∶5时,相应的木薯淀粉-丙烯酰胺接枝共聚物的胶合性能相对最好,以其制备的胶合板干状剪切强度为1.46 MPa、(23±2)℃冷水浸泡24 h后的剪切强度为0.87 MPa、(63±1)℃热水浸泡3 h后的剪切强度为0.84 MPa,符合GB/T 9846—2015《普通胶合板》对Ⅱ类胶合板的要求。

接枝型天然橡胶基吸水膨胀橡胶的制备及吸水膨胀性能

以脱蛋白天然橡胶(DPNR)胶乳作为改性橡胶的基材,在氧化还原引发体系作用下,基于橡胶大分子链中烯丙基与乙烯基单体的自由基乳液接枝共聚反应实现丙烯酸(AA)在DPNR链上的接枝共聚,从而制备了一种亲水性AA接枝改性DPNR共聚物(DPNR-g-PAA),通过傅里叶变换红外光谱、核磁共振氢谱、扫描电子显微镜和称重法表征了DPNR-g-PAA的分子结构、断面形貌和吸水膨胀性能。结果表明,DPNR-g-PAA作为吸水膨胀橡胶,其薄膜吸水率可达85.06%,DPNR的表面透湿性显著提高;与传统物理共混或溶液接枝共聚反应制备吸水膨胀橡胶工艺相比,由自由基乳液接枝共聚制得的DPNR-g-PAA具有一定的优势。

三元共聚生物质基矿山爆破抑尘剂的制备及性能研究

以接枝共聚制备羧甲基纤维素钠(CMC-Na)-羧甲基淀粉钠(CMS-Na)-丙烯酰胺(AM)三元复合高分子抑尘剂,以黏度为测试指标,通过正交试验探索抑尘剂最优配比。用扫描电镜(SEM)、傅里叶红外光谱(FT-IR)、热重(TG)对接枝共聚产物进行表征,对抑尘剂黏度、抗风蚀性、保水性、渗透性等理化特性进行测试。结果表明:CMC-Na∶CMS-Na∶PVA∶AM=8∶8∶3∶16时,制备抑尘剂最大黏为52689 mPa·s;借助黏度及保水性指标确定抑尘剂喷洒最佳体积分数为8%;木质素磺酸钠和三乙醇胺最优添加量分别为抑尘剂质量分数的0.4%和4%。红外光谱显示丙烯酰胺接枝到羧甲基淀粉和羧甲基纤维素钠上,扫描电镜显示抑尘剂对粉尘的凝并和黏结性能显著,抗风蚀性实验表明抑尘剂固尘率为85.47%。

新型两性淀粉基絮凝剂的制备

以过硫酸铵为引发剂,在可溶性淀粉上同时接枝丙烯酰胺、甲基丙烯酰氧乙基三甲基氯化铵和丙烯酸,制备了一种新型两性淀粉基絮凝剂。采用红外光谱对接枝共聚物的结构进行表征,证明3种单体成功接枝到淀粉上。为制备高电荷密度、阴阳离子相互匹配的淀粉接枝聚合产品,固定3种单体摩尔比为1∶1∶1,淀粉与单体质量比1∶2.47,通过正交试验对合成条件进行优化,确定接枝共聚反应的最佳反应条件:淀粉与过硫酸铵质量比25∶1,引发时间22 min,反应温度63℃,pH 4~5,聚合体系有效物质量分数17%。最佳反应条件下单体总转化率为99.15%,接枝物的接枝率达到225%,接枝效率达到97.72%。研究提高了在水介质中制备淀粉基改性类高分子絮凝剂的有效物浓度,有利于节约储运成本。

Comparison of selective flocculation of low grade goethitic iron ore fines using natural and synthetic polymers and a graft copolymer

This study aims to beneficiate low grade goethitic iron ore fines using a selective flocculation process. Selective flocculation studies were conducted using different polymers such as starch amylopectin(AP), poly acrylic acid(PAA), and a graft copolymer(AP-g-PAA). The obtained results were analyzed; they indicate the enhancement of the iron ore grade from 58.49% to 67.52% using AP-g-PAA with a recovery of 95.08%. In addition, 64.45% Fe with a recovery of 88.79% was obtained using AP. Similarly, using PAA, the grade increased to 63.46% Fe with a recovery of 82.10%. The findings are also supported by characterizing concentrates using X-ray diffraction(XRD) and electron probe microanalysis(EPMA) techniques.

辐射法制备淀粉基超级吸水材料及其性能

本文以淀粉与丙烯酸单体为主要原料,采用钴-60γ射线共辐射法制得淀粉基超级吸水材料(Super absorbent polymer,SAP)。通过傅里叶变换红外光谱对SAP进行化学结构表征。扫描电镜图显示,SAP颗粒表面含有大量中孔结构。热重分析测试结果表明,SAP较原始淀粉样品的热稳定性有明显提升。吸收剂量、丙烯酸与淀粉的投料比显著影响SAP的吸水性能。通过筛选反应条件,SAP的吸水(去离子水)倍率可达到532 g/g(吸收剂量:20 kGy;交联剂:80 mg/L;淀粉与丙烯酸投料比:1/2)。将SAP负载硝酸钾和磷酸钠,结果表明,SAP能够高效释放负载的离子,磷酸根离子释放率为80%,钾离子为82%。

几种添加剂对聚丙烯膜预辐射接枝丙烯酸和丙烯酰胺的增强效应

Grafting of acrylic acid (AAc) and acrylamide (AAm) onto preirradiated PP film was performed in aqueous solution of AAc and AAm, respectively. Electron beam accelerator was used as irradiation source. The effect of ferrous sulfate, sodium nitrate, methanol and glucose on the degree of grafting was demonstrated. The function of the different additives was compared by the grafting of different monomers (AAc and AAm). The results show that the four of these additives are elective on the grafting of AAc. Only two of these additives, ferrous sulfate and methanol were effective on the grafting of AAm.

两种共聚单体对淀粉/聚丙烯酸钠超级吸水材料耐盐性能的影响

利用γ射线共辐照法,制备了由两种共聚单体接枝交联而成的淀粉基超级吸水材料(Super absorbent polymer,SAP)。傅里叶变换红外光谱证明了丙烯酰胺(AM)和2-丙烯酰氨基-2-甲基-1-丙烷磺酸(AMPS)分别被引入到淀粉/聚丙烯酸钠(Starch-g-PAA)SAP中。采用热重分析法研究了SAP的热分解行为。通过引入AM和AMPS单体,SAP的耐盐性得到显著提升,引入AMPS的SAP在生理盐水中的吸液倍率从46 g/g(未添加AMPS)提高至81 g/g(AA∶AMPS=3∶1)。