用次亚磷酸钠作为链转移剂合成聚丙烯酸钠的研究

采用丙烯酸和丙烯酰胺作为单体,次亚磷酸钠作为链转移剂,过硫酸铵为引发剂,通过水相自由基聚合,获得适合于小粒径重质碳酸钙浆料分散用的聚丙烯酸钠。实验结果表明：引发剂用量、次亚磷酸钠用量、单体浓度和丙烯酰胺用量等反应条件均对分散剂的相对分子质量有较大影响。实验结果还表明：这种共聚物在结构上引入磷酸根基团,对小粒径重质碳酸钙颗粒起到很好的分散效果。     

AMPS共聚物的合成及用于造纸废水絮凝处理的研究

主要研究了AMPS(2-丙烯酰胺基-2-甲基丙磺酸)共聚物的合成及应用。通过研究引发剂的用量、共聚单体的用量、EDTA用量、反应后期温度等因素对AM和AMPS共聚合反应的影响，发现在中性水溶液介质中，在氧化还原引发体系与偶氮类引发剂共同作用下，在5℃的低温下引发聚合反应，当引发剂用量为单体质量0．03％，反应后期温度为40℃时，可获得相对分子质量为1810万的AM和AMPS共聚物。并研究聚合氯化铝／AM和AMPS共聚物体系在造纸脱墨废水絮凝处理的应用，研究表明：AM和AMPS共聚物用量为0．75ms／L，与之复配的聚合氯化铝(PAC)最佳用量是100mg／L，其中1134万相对高分子质量的两性AMPS和AM、MAC共聚物效果更佳，与之复配的PAC用量可减少到75mg／L，CODCr去除率都达70％以上。     

碳纤维聚合体在DMSO中溶解的研究

对采用水相悬浮聚合工艺制取的聚丙烯腈基(PAN)碳纤维聚合体进行真空干燥,得到不同含水率的聚合体,用纯二甲基亚砜(DMSO)溶剂进行溶解对比,了解聚合体干燥、溶解工艺与纺丝原液黏度之间的关系,据此为碳纤维原丝DMSO二步法工艺研究提供合理的纺丝原液制备工艺参数和生产依据。     

以季戊四醇为核分子制备的BCPAM对纸张有显著增强效果

正华南理工大学制浆造纸工程国家重点实验室丛珊等人,以季戊四醇(PETL)为聚合反应的支化剂,硝酸铈铵为引发剂,选用二甲基二烯丙基氯化铵(DADMAC)为阳离子单体,丙烯酰胺(AM)为单体,通过自由基聚合反应制备支化阳离子聚丙烯酰胺(BCPAM);利用红外光谱、13C-NMR核磁共振谱对所合成的产物结构进行了表征;研究引发剂的用量、阳离子单体用量对产物特性黏度的影响;以产物作为纸张增强剂,研究其对纸张强度性能的影响。研究结果表明,所合成的产物为BCPAM;     

“Cr^2＋＋BPO”体系引发的活性自由基聚合

本文以陈化的“Ｃｒ＾２＋＋ＢＰＯ”为引发剂，以Ｎ，Ｎ－二甲基甲酰胺（ＤＭＦ）为溶剂，在各种条件下引发了甲基丙烯酸甲酯（ＭＭＡ）的聚合。通过对低单体浓度下的聚合反应的研究，证明了ＰＭＭＡ的相对分子质量随单体转化率而上升的现象不是由凝胶效应所造。通过对陈化体系变温聚合的研究，及对其聚合产物的立构规整性的分析，进一步说明了是由三价铬离子络合的链自由基引发ＭＭＡ进行“活性”聚合的这一反应机理。     

一步法制备纤维素氯乙酸酯及其原子转移自由基接枝共聚

以离子液体为反应介质,氯乙酰氯为酰化试剂,在不加任何催化剂的条件下,一步法制备出纤维素氯乙酰酸酯.研究了反应条件(酰化试剂用量、反应时间、反应温度)对纤维素取代度(DS)的影响,并对产物结构进行表征(FT-IR、NMR).随后以纤维素氯乙酰酸酯为大分子引发剂,引发了甲基丙烯酸甲酯(MMA)在离子液体中的原子转移自由基聚合(ATRP).研究结果表明,MMA在离子液体中的聚合是活性/可控的.     

以季戊四醇为核分子制备的BCPAM对纸张有显著的增强效果

正华南理工大学制浆造纸工程国家重点实验室丛珊等人,以季戊四醇(PETL)为聚合反应的支化剂,硝酸铈铵为引发剂,选用二甲基二烯丙基氯化铵(DADMAC)为阳离子单体,丙烯酰胺(AM)为单体,通过自由基聚合反应制备支化阳离子聚丙烯酰胺(BCPAM);利用红外光谱、     

二异丁烯/顺丁烯二酸酐两亲共聚物复鞣剂的制备及应用

以二异丁烯(DIB)和顺丁烯二酸酐(MA)为原料,过氧化苯甲酰(BPO)为引发剂,通过溶液聚合制备了Poly(DIB—MA)两亲共聚物复鞣剂,对其合成过程及聚合产物的结构进行了研究与表征。研究表明:DIB与MA在溶液中可以形成电荷转移络合物(CTC),共聚物组成取决于CTC,与投料比无关,聚合反应时间控制在7h为好,共聚物具有表面活性。应用试验表明,poly(DIB-MA)具有较强的复鞣效应。经其复鞣后,坯革的收缩温度、增厚率、撕裂强度以及抗张强度均有不同程度的增加,共聚物复鞣剂可以促进栲胶、染料等阴离子材料向皮内进行渗透。     

丙烯腈—马来酸酐共聚物合成的研究（一）

以亚硫酸氢钠－过硫酸铵为引发体系,进行丙烯腈同马来酸酐的水相沉淀共聚合反应。讨论了单体浓度、链转移剂浓度和引发剂浓度对共聚物分子量、收率及组成的影响。     

聚丙烯腈基碳纤维前驱体生产新方法

在聚丙烯腈(PAN)基碳纤维前驱体的不同工业生产方法中,最常用的是在二甲基亚砜(DMSO)溶液中聚合纺丝,和在二甲基乙酰胺(DMAC)水相悬浮液中聚合纺丝。介绍了一种结合上述两种方法优点的新方法,即在工业上实现经水相悬浮聚合后再在DMSO中纺丝的两步法。该方法成功的关键,是由聚合物粉末和水性溶剂开始,有效地制备良好的纺丝溶液。     

Preparation and Characterization of Copolymers of Modified Starches and Polyacrylonitrile

Starch graft polyacrylonitrile (S-g-PAN) copolymers were prepared from a commercial unmodified cornstarch and from three chemically modified commercial cornstarch products including Amaizo 395 (highly acid modified, HAM), Amaizo 590 (highly hypochlorite oxidized, HHO) and Amaizo 791D (hydroxyethyl, highly acid modified, HEHAM). Using similar reaction conditions and ratio of monomer to starch (1:1), the percentages of PAN in the copolymers ranged from 39% for the unmodified starch to 48% for the modified starches. Only 5% of the PAN of the copolymer prepared from unmodified starch could be extracted by dimethylformamide (DMF) treatments compared to 22–28% for copolymers prepared from the modified starches. However, copolymers from the modified starches apparently contained relatively high proportions of low-molecular-weight copolymer along with homopolymer. Acid hydrolysis treatment of the DMF insoluble and DMF soluble fractions to remove starch from the various copolymers gave essentially quantitative yields of PAN. However, these PAN samples exhibited large differences in DMF solubility. The copolymer from the HHO starch was by far more soluble in DMF, had the lowest number average molecular weight, and had a grafting frequency of 2.5–3 times greater than those of the other copolymers. This study indicated that hypochlorite modified starch substrates may be particularly suitable for obtaining copolymers with widely different properties than copolymers having the acid modified starch substrates.     

Scanning Electron Microscopy of Saponified Starch-g-Polyacrylonitrile

A series of starch-g-polyacrylonitrile (PAN) copolymers was prepared by ceric ammonium nitrate initiation, the only differences being in the degree of swelling and gelatinization of starch granules. This variable was governed by the temperature at which starch-water slurries were heated before graft polymerization. Graft copolymers were then saponified with sodium hydroxide to convert the nitrile substituents of PAN to sodium carboxylate and carboxamide. Comparison of scanning electron micrographs of each starch-g-PAN copolymer with those of the corresponding saponified product showed particles which retain the outward appearance of graft polymerized starch granules. Since starch is soluble in alkali and PAN is also rendered soluble on alkaline saponification, a crosslinking reaction either during graft polymerization or during base saponification is proposed to account for the observation that granules are not totally disrupted or dissolved.     

新型阳离子染料皂洗剂的合成及应用

以马来酸酐(MA)、丙烯酸(AA)和丙烯酸十八酯(SA)为原料,采用偶氮二异丁氰作为引发剂,在乙醇介质中,共聚生成了较高相对分子质量和高羧基电荷密度的聚马来酸酐-丙烯酸-丙烯酸十八酯(MA-AA-SA)三元共聚物PMAS,并将其用于腈纶织物染色后的皂洗工序中.通过探讨单体配比、引发剂用量、反应时间和皂洗剂用量等因素对皂洗性能的影响,得到优化的合成工艺条件为:m(MA)∶m(AA)∶m(SA)=2∶6∶2.5,ω(引发剂)=2.5％(相对于原料的质量分数),反应温度65℃,反应时间7h;应用试验表明,PMAS用量为2 g/L时,皂洗效果最佳,织物皂洗后湿摩擦牢度达4～5级,干摩擦牢度达5级,且具有良好的防沾色性能.     

Synthesis and Properties of Polyacrylamide-Starch Graft Copolymers

Graft polymerization of acrylamide onto rice starch was investigated under different conditions using potassium persulphate, benzoyl peroxide or potassium permanganate as initiator. This has led to establishment of the most appropriate grafting conditions for each of these initiators. Under these conditions grafting was characterized by two rates regardless of the initiator used. The first rate occurred during the initial stages of polymerization while the second during the later stages. The first rates of grafting for the three initiators were very close indicating the insignificant effect of the nature of the initiator on grafting during the initial stages of the reaction. On the other hand, the second rates of grafting exhibited the order: potassium persulphate < benzoyl peroxide < potassium permanganate, reflecting the role played by the nature of initiator during the later stages of the reaction. Substantial differences in solubility were observed between polyacrylamide-starch graft copolymers and unmodified starch as well as among copolymers prepared using the three initiators. Although the copolymers acquired higher solubility percent than the unmodified starch, yet nature of initiator, graft yield, structural changes in the copolymer occuring during grafting and the temperature of solubility measurement determined the solubility percent. Copolymers prepared using benzoyl peroxide or potassium persulphate showed lower viscosity than the unmodified starch. The opposite was the case with respect to copolymer prepared using potassium permanganate.     

过硫酸铵引发阳离子淀粉接枝共聚物合成与表征

采用水溶液聚合方法,以过硫酸铵(APS)为引发剂,将玉米淀粉(St)与丙烯酰氧乙基三甲基氯化铵(DAC)单体接枝聚合,制备阳离子淀粉高分子聚合物。讨论单体质量比、引发剂用量、反应温度和反应时间等因素对聚合物阳离子度的影响。结果表明：当加入淀粉质量1.0%的过硫酸铵,DAC与淀粉质量比2.5:1,50℃反应8h时,接枝共聚物的阳离子度最高可达53.68%。用红外光谱、扫描电镜、热失重分析对接枝共聚物结构进行表征,表征结果均证实阳离子淀粉高分子聚合物制备成功。     

磺甲基化苯酚聚合物复鞣剂的酶促合成及性能研究

以亚硫酸钠/亚硫酸氢钠/甲醛为磺甲基化试剂,对苯酚进行磺甲基化改性,在辣根过氧化物酶(HRP)/H2O2的催化体系下,磺甲基化苯酚进行聚合反应,制备了磺甲基苯酚聚合物鞣剂。分别讨论了苯酚磺甲基化反应和酶催化聚合反应的主要影响因素。用红外光谱(FTIR)、紫外可见光谱(UV-Vis)和凝胶渗透色谱(GPC)对聚合产物的结构和性能进行了表征。GPC检测结果显示该聚合产物的相对分子质量在40000左右。应用结果表明,应用革的收缩温度从46℃(鞣制前)提高至76℃(鞣制后),聚合物复鞣剂的用量为7%时产物具有良好的复鞣和匀染性能。     

Graft Copolymers of Starch and Polyacrylonitrile. Effect of Source

Graft copolymers of tuber and legume starches with polyacrylonitrile (PAN) have been prepared. Molecular weight, frequency of grafting, and adsorbencies of saponified products have been investigated. Yield and add-on of granular graft copolymers are dependent on the source of starch. Parameters for gelatinized graft copolymers are almost constant. Yield, add-on, molecular weight and adsorbencies are different for the granular graft copolymer of garden pea starch. On pretreatment up to 70°C, these parameters are comparable with those of other starch graft copolymers.     

新型引发体系对淀粉接枝共聚反应的影响研究

为探讨新型引发体系对淀粉接枝共聚反应的影响,以玉米淀粉为原料,采用过硫酸铵-亚硫酸氢钠引发体系合成了淀粉接枝丙烯酸丁酯共聚物,确定了丙烯酸丁酯浓度、引发剂浓度、过硫酸铵与亚硫酸氢钠间摩尔比、反应温度、反应时间等工艺条件.并通过红外光谱、X-射线衍射仪和扫描电子显微镜对共聚产物结构进行了表征.过硫酸铵-亚硫酸氢钠引发体系可有效降低接枝共聚反应的活化能,从而降低反应温度,且该接枝淀粉的合成工艺简单,成本较低.     

三元共聚物对纺织厂循环冷却水的阻垢性能

针对纺织厂运转过程中的循环冷却水浓缩导致结垢的问题,以2-丙烯酰胺基-2-甲基丙磺酸(AMPS)、烯丙基磺酸钠(SAS)、丙烯酸(AA)为反应单体,过硫酸铵(APS)为引发剂,异丙醇(IPA)为分子量调节剂,通过水溶液自由基聚合法制备了SAS/AA/AMPS三元共聚物,研究共聚物的投加量、钙离子浓度、p H值对碳酸钙和硫酸钙阻垢性能的影响,通过FT-IR、SEM和XRD分别对共聚物基团、晶体晶貌、晶体结构进行表征。结果表明:在投加量为3 mg/L、钙离子浓度为360 mg/L时,对碳酸钙的阻垢率高达99%;投加量为5 mg/L、钙离子浓度为1 100 mg/L、p H值为8时,对硫酸钙的阻垢率也都能达到90%。三元共聚物能使碳酸钙的晶体形状发生改变,硫酸钙晶体的结晶度降低,共聚物适用于低硬度弱碱性水质环境阻垢处理。