淀粉基阳离子絮凝剂的研制及性能测试

用可溶性淀粉为原料,通过接枝改性合成了一种淀粉基阳离子絮凝剂(MSF),其最佳制备工艺条件为:淀粉与丙烯酰胺的质量比为1:2,引发剂用量为0.6 g,反应温度为50 ℃,接枝时间为3.5 h;阳离子化条件为:甲醛和二甲胺摩尔比为1.0:1.4,反应时间2.5 h,反应温度50 ℃.产物结构经FTIR证实.用其处理番茄废水后,废水的透光率提高了78.2%、TOC下降了22.5%、COD下降了37.25%,结果表明该产品对高浓度有机废水的絮凝性能优于聚丙烯酰胺高分子絮凝剂(PAM).     

微晶纤维素—丙烯酰胺接枝共聚产物对洗煤废水的絮凝作用

锰盐引发微晶纤维素—丙烯酰胺接枝共聚所得共聚混和物:纤维素—丙烯酰胺接枝共聚物(GCAM)和丙烯酰胺均聚物(PAM)在实验室条件下处理洗煤皮水,取得了良好的效果。研究了混和物中接枝物、均聚物、水解度、用混和物作非离子絮凝剂、阴离子絮凝剂对处理洗煤废水的影响及絮凝剂与洗煤废水pI值的关系。     

有机阳离子高分子絮凝剂

近年来,有机阳离子高分子絮凝剂得到国内外学者的广泛重视.它的研究、开发、应用都取得了显著进展.本文对此进行评述和介绍,内容涉及阳离子型聚丙烯酰胺接枝共聚物、羟基醚化类、二烷基二烯丙基卤化铵类和环氧氯丙烷与胺反应物,特别是近年来淀粉等天然高分子改性阳离子型絮凝剂和人工合成的无毒有机阳离子高分子絮凝剂.     

阳离子淀粉接枝絮凝剂的制备研究——淀粉和丙烯酰胺接枝共聚物的胺甲基化反应

研究了淀粉和丙烯酰胺接枝共聚物的胺甲基化反应合成阳离子高分子絮凝剂,试验各种反应条件对胺甲基化反应的影响;并探讨一步法进行该共聚物的胺甲基化反应,胺化度虽略低于二步法,但差别不大,操作简便,同样可制得性能较好的阳离子高分子絮凝剂。     

淀粉接枝聚丙烯酰胺反相胶乳的胺甲基化反应

淀粉接枝聚丙烯酰胺反相胶乳的胺甲基化反应卢绍杰刘瑞贤孙希明卫乃勤杨光中（天津大学化学系３０００７２）关键词反相乳液淀粉接枝Ｍａｎｎｉｃｈ反应阳离子淀粉接枝聚丙烯酰胺是聚丙烯酰胺有重要应用价值的改性产品，在采油、造纸、水处理等部门有着广泛的应用。它的制...     

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。     

接技型聚丙烯酰胺高分子絮凝剂结构和性能的研究

研究了接枝型聚丙烯酰胺高分子絮凝剂的结构和性能的关系。通过常规分析测试及SEM,IR,TG等结构分析方法剖析接枝共聚物的结构,从而解释接枝型聚丙烯酰胺的特性。     

淀粉基强阳离子两性絮凝剂的合成

淀粉基强阳离子两性絮凝剂的合成;淀粉; 阳离子; 两性絮凝剂     

两性淀粉接枝共聚物在中性抄纸中的应用

为考察两性淀粉与丙烯酰胺接枝共聚及阳离子合成的具有功能化、网络化的多元变性淀粉对纸张的增强效果,采用废纸浆为原料,在中性抄纸条件下,对该多元变性淀粉的增强应用性能进行了研究。结果发现,两性淀粉与丙烯酰胺接枝共聚物(AS-g-PAM)及其阳离子化的衍生物(AS-g-CPAM)比两性淀粉具有更好的增强效果,尤其可大幅度提高纸张的环压强度。与两性淀粉比较,用量为0.5%AS-g-PAM和AS-g-CPAM可分别提高环压指数22%和45%以上,对纸张的抗张指数、耐破度等也比使用两性淀粉有不同程度的提高,同时,AS-g-CPAM在0.05%的低用量时,仍具有较好的增强效果。     

淀粉-磺甲基化聚丙烯酰胺接枝共聚物的合成及性能

用淀粉-聚丙烯酰胺接枝共聚物(S-g-PAM)同多聚甲醛及亚硫酸钠反应,合成了淀粉-磺甲基化聚丙烯酰胺接枝共聚物(S-g-SPAM)。该磺化物的水溶液在试验浓度范围内(0.1～1.0％),为假塑性流体,对高岭土悬浮液的絮凝,由沉降速度,上层清液相对吸光度可知,S-g-SPAM(接枝链分子量为1.03×10⁵,磺甲基化度30％)的絮凝能力优于相应的未磺化的S-g-PAM,也比聚丙烯酰胺(分子量2.5×10⁶)强。     

Synthesis of cationic guar gum-graft-polyacrylamide at low temperature and its flocculating properties

Acrylamide grafted cationic guar gum (CGG-g-PAM), induced by ceric ammonium sulfate, was synthesized using aqueous polymerization technique at 10 °C and the flocculation property was studied with high-turbidity tobacco wastewater (NTU > 4500). Thus five grades of graft copolymers were obtained through alteration of initiator and monomer concentrations in order to understand the effect of molecular weight on flocculation. The grafted copolymer was characterized by FTIR and SEM. Study of DTG demonstrated that CGG-g-PAM had better heat-resistant performance than guar gum, cationic guar gum (CGG) and polyacrylamide. The dosage of polyaluminium chloride (PAC) and CGG-g-PAM, pH value and molecular weight were considered to be the factors that can influence flocculation efficiency. The result showed best flocculation efficiency occurs at pH 5 when the dosage of CGG-g-PAM and PAC are 3.6 ppm and 120 ppm, respectively. The percentage of turbidity and COD removal are 98% and 24% correspondingly, and its flocculating efficiency prevails over that of CGG and cationic polyacrylamide (CPAM).     

Synthesis and Biodegradation of St-g-poly（MMA-co-VAc） Initiated by Manganic Pyrophosphate

Methyl methacrylate (MMA) and vinyl acetate (VAc) were grafted onto corn starch with manganic pyrophosphate { [Mn(H2P2O7)3]^3- } as the initiator and water as the reaction medium, The influences of reaction conditions, including pH value, initiator concentration, monomer concentration and its composition, on percent grafting and grafting efficiency were investigated. The graft copolymer was characterized by means of IR spectroscopy, scanning electron micrograph(SEM) and ^1H NMR spectroscopy. The biodegradation experiment showed that the degradation of corn starch-g-poly(MMA-co-VAc) was mainly from starch. However,after poly VAc in the side chain was transformed into poly vinyl alcohol(PVA), both starch and the grafted side chain could be degraded completely.     

Selective crystallization of calcium salts by poly(acrylate)-grafted chitosan

The biopolymer chitosan was chemically modified by grafting polyacrylamide or polyacrylic acid in a homogeneous aqueous phase using potassium persulfate (KPS) as redox initiator system in the presence of N,N-methylene-bis-acrylamide as a crosslinking agent. The influence of the grafted chitosan on calcium salts crystallization in vitro was studied using the sitting-drop method. By using polyacrylamide grafted chitosan as substrate, rosette-like CaSO4 crystals were observed. This was originated by the presence of sulfate coming from the initiator KPS. By comparing crystallization on pure chitosan and on grafted chitosan, a dramatic influence of the grafted polymer on the crystalline habit of both salts was observed. Substrates prepared by combining sulfate with chitosan or sulfate with polyacrylamide did not produce similar CaSO4 morphologies. Moreover, small spheres or donut-shaped CaCO3 crystals on polyacrylic acid grafted chitosan were generated. The particular morphology of CaCO3 crystals depends also on other synthetic parameters such as the molecular weight of the chitosan sample and the KPS concentration.     

聚丙烯酰胺的改性和表征

用甲醛(F)和二氰二胺(D)改性聚丙烯酸胺(PAm),制得新型阳离子聚电解质PAm·MG,对PAm·MG的合成和表征进行了研究。合成反应通过两步进行,先使PAm与F反应,生成羟甲基化产物PAm·M,然后在酸性条件下使PAm·M与D反应,制得PAm·MG.控制F用量,得到不同取代度的PAm·M.和PAm·MG。PAm·MG在水溶液中能与阴离子聚电解质形成复合物沉淀证明PAm·MG带有阳离子基团。元素分析及电位、浊度滴定结果表明PAm·M中的羟基完全与D发生了反应。SALLS测得的M_w证实了PAm在改性过程中分子链未发生降解。     

Grafting polyelectrolytes onto polyacrylamide for flocculation 2. Model suspension flocculation and sludge dewatering

Low-molecular-weight high-charge-density cationic poly(diallyldimethylammonium chloride) (polyDADMAC) was grafted onto high-molecular-weight nonionic polyacrylamide (PAM) via a free radical mechanism using a gamma radiation technique. The graft copolymers having various charge densities were evaluated as flocculants for titanium dioxide (TiO₂) model suspensions, and as conditioners for a pulp and paper mill sludge. Their flocculation performance was optimized with respect to polymer composition, gamma irradiation time and polymer dosage. Measurements included turbidity, particle size distribution and drainage rates. The graft copolymers showed a significant improvement over the homopolymers and dual polymer systems in their flocculation and sludge dewatering performance. Received: 6 April 1998 Accepted in revised form: 28 August 1998     

UV-induced graft polymerization of acrylamide on cellulose by using immobilized benzophenone as a photo-initiator

Photo-active moiety, benzophenone, was incorporated onto cotton fabrics by using butyl tetracarboxylic acids (BTCA). Then, grafting of polyacrylamide on the cotton fabrics was performed by exposing the fabrics to longer UV wavelength irradiation. The chemical structure and thermal properties of the polyacrylamide grafted cotton fabrics were investigated by SEM, FTIR, XRD, and TGA, and the results verified the successful grafting of polyacrylamide on cotton fabrics. Also, it was observed that active chlorine contents were created on the polyacrylamide grafted cotton fabrics through simple chlorination process, and the chlorine treated cotton fabrics showed excellent antibacterial abilities like the powerful cyclic amide halamines.     

聚苯乙烯接枝淀粉纳米晶的制备

通过淀粉纳米晶与苯乙烯乳液聚合的方法制备了聚苯乙烯接枝淀粉纳米晶并用FTIR和1HNMR进行了表征;制备了不同接枝聚苯乙烯单体与淀粉纳米晶的物质的量之比(MS)的聚苯乙烯接枝淀粉纳米晶,在苯乙烯单体和淀粉纳米晶摩尔比(M/SN)为2,反应时间为5～12h条件下,所得MS为0.15～0.67.X-射线衍射结果表明,接枝聚苯乙烯几乎不会改变淀粉纳米晶的晶型,但结晶度随着MS的增加而下降.     

Copolymers of modified starches with polyacrylonitrile

A study was made of the ceric ammonium nitrate-initiated graft polymerization of acrylonitrile (AN) onto a number of modified starches that had been reduced in molecular weight by either acid, hypochlorite, or enzyme treatment. With highly soluble starches, much of the starting material was recovered as ungrafted carbohydrate, and the reaction product was largely dimethylformamide-soluble polymer with a high polyacrylonitrile (PAN) content. The molecular weight of grafted PAN was lower when the modified starches existed as granules in water dispersion; however, heating (60°C) an aqueous slurry of an acid-modified corn starch (with intact granules) before the reaction had relatively little effect on the composition of the copolymer. Decreasing the concentrations in water of modified starch and AN resulted in more frequent and lower molecular weight grafts of PAN. Aqueous methanol as a reaction medium for an acid-modified starch with intact granules led to more frequent grafting of lower molecular weight PAN than when water alone was used. The number of grafted chains, however, was fewer than found with unmodified wheat starch under comparable conditions. A modified starch with the granule structure completely broken down gave no detectable reaction in aqueous methanol.