【作者】 李曼丽；

【导师】 祝志峰；

【作者基本信息】 江南大学 ， 纺织工程， 2008， 硕士

【摘要】 为了提高接枝淀粉浆料的接枝效率,制备高性能的接枝淀粉浆料,本论文在淀粉与乙烯基单体的接枝共聚合反应之前,通过对淀粉进行烯丙基醚化预处理,在淀粉大分子上引入可聚合的碳-碳双键,再将含有碳-碳双键的淀粉分别与丙烯酸和丙烯酸甲酯单体进行接枝共聚合反应,水相合成出丙烯酸接枝醚化淀粉(AS-g-PAA)和丙烯酸甲酯接枝醚化淀粉(AS-g-PMA),探索烯丙基醚化预处理对AS-g-PAA与AS-g-PMA接枝效率的影响,还研究了此种预处理对AS-g-PMA性能的影响。并通过改变醚化剂对淀粉的投料比调节淀粉烯丙基化变性的深度,研究淀粉烯丙基醚化预处理深度与接枝淀粉浆料接枝效率和性能之间的内在联系。实验结果表明,在接枝共聚合反应前将淀粉经烯丙基预处理,当烯丙基淀粉的取代度在0.01-0.068范围内时,这种醚化预处理方法可以使AS-g-PAA与AS-g-PMA的接枝效率提高10%-20%,并能显著改善AS-g-PMA浆料对纤维的粘附性能以及浆膜性能。实验证实AS-g-PMA浆料的醚化取代度以0.011-0.023为宜。淀粉烯丙基醚化预处理不仅为提高接枝淀粉浆料的接枝效率提供了一条新的途径,而且能够改善接枝淀粉浆料的应用性能。本文还研究了淀粉烯丙基醚化预处理的制备工艺,阐明了NaOH用量、异丙醇-水反应介质中水的含量、反应温度、反应时间以及烯丙基氯对淀粉的投料比等工艺参数对烯丙基醚化反应效率的影响。实验结果表明,所考虑到的工艺参数对淀粉烯丙基醚化反应效率有着显著的影响,NaOH对烯丙基氯的摩尔比为1.5:1、含水量为20%,在30℃的条件下反应24小时,可以使该反应的效率保持在50%以上。另外,本文也通过实验研究了AS-g-PMA与PVA1799之间的混合比例对纤维粘附性能和浆膜性能的影响,并初步探讨了AS-g-PMA的浆纱性能。通过与目标配方的对比,探讨AS-g-PMA浆料替代PVA的可行性。实验结果表明,与当前浆纱中的常用浆料配方相比,AS-g-PMA能够在保持浆纱质量不变的条件下明显减少PVA用量。更多还原

【Abstract】 Through allyl etherification pretreatment of starch, an attempt had been made to enhance the graft efficiency and improve the properties of grafted starch used as warp sizing agents before the graft copolymerization between starch and vinyl monomers. By allyl etherification pretreatment of introducing polymerisable double bonds onto starch, graft copolymerization reactions between starch and acrylic acid/methyl acrylate were both carried out in aqueous dispersion to synthesize allyl starch graft PAA (AS-g-PAA) and allyl starch graft PMA (AS-g-PMA) for warp sizing. Furthermore, the influence of allyl etherification pretreatment on the graft efficiency of AS-g-PAA and AS-g-PMA and behaviors of AS-g-PMA was surveyed. In addition, the degree of substitution (DS) of allyl starch was adjusted through varying the feeding ratio of etherifying agent to starch. The intrinsic relation between the DS value of allyl starch and the graft efficiency and behaviors of grafted starch sizing agents was systematically studied.The experimental results indicated that, by introducing allyl groups onto starch before the copolymerization, the etherification pretreatment can enhance the graft efficiency of AS-g-PAA and AS-g-PMA by about 10% -20% when the degree of substitution (DS) of allyl starch was in a range of 0.01 to 0.068. The adhesion to fibers and film behaviors of AS-g-PMA were also remarkably improved. The experiments prove that proper DS value of AS-g-PMA was in the range of 0.011 to 0.023. Obviously, not only does allyl etherification pretreatment of starch supply a convenient way to enhance the graft efficiency, but also it broadens the serviceability of grafted starch.The paper also clarified the influence of such technological variables as sodium hydroxide amount, water content in water-isopropyl alcohol medium, allyl chloride concentration, reaction temperature and reaction time on allyl etherification reaction efficiency. The experimental result demonstrated that the variables considered showed evident effect on the reaction efficiency. For the etherification, a condition of 1.5:1 for the molar ratio of sodium hydroxide to allyl chloride, 20% for the water content, and at 30℃under 24h reaction is sufficient to retain the reaction efficiency above 50%.Moreover, the effects of blending ratio of AS-g-PMA to PVA1799 on blending film behaviors and adhesion to fibers were also investigated. And sizing properties of AS-g-PMA were primarily studied. The possibility of using AS-g-PMA to substitute PVA component was evaluated by contrast experiments. The results of experiment show that compared with the conventional size formulation used in modern sizing engineering AS-g-PMA can largely reduce the usage of PVA while the quality of sizing yarns doesn’t fall.更多还原