AKD改性聚氨酯预聚体共混物的制备及其中性施胶性能的研究

Study on the preparation of the mixtures of AKD modified polyurethane prepolymers and their neutral sizing performance

将烷基双烯酮二聚物（AKD）与羟基封端的聚氨酯预聚体反应,制备了一种末端为硬脂酰乙酸酯基的大分子施胶剂（SPU）,使用N-甲基二乙醇胺作为扩链剂和阳离子化剂,使用硫酸二甲酯作为中和剂,增加其阳离子性,并使其具有较强的乳化和分散能力,能够对未参加反应的AKD进行有效地分散,得到稳定的流动性良好的施胶剂乳液;在中性条件下进行施胶,具有良好的留着性和施胶效果.当w（施胶剂）=0.2%时,施胶度可达到36 s,熟化后则达到53 s,证明所合成的中性施胶剂在中性条件下具有良好的留着性和施胶效果.上述中性施胶剂的合成条件为：m（扩链剂）：m（SPU）=0.3：1,m（硫酸二甲酯）：m（SPU）=0.3：1,Zeta电位值为20～40 mV.

Based on the principle of molecular structure design, a large molecular sizing agent with the end group of stearyl acetate was prepared via reacting alkyl ketene dimmer（AKD） with the pre-polymer of hydroxyl-terminated polyurethane. Using N-methyldiethanolamine, as chain extender and cationized reagent, dimethyl sulfate as neutralizer, we enhanced the positive charge and emulsifiability of the sizing agent which could effectively disperse the un-reacted AKD into water. Thus, a stable emulsion-based neutral sizing agent with good flowability and sizing performance was obtained. The sizing experiments showed that a sizing degree of 36s and 53s could be achieved before and after aging with a dosage of 0.2% sizing agent. The optimized molar ratio of m（ chain extender） ： m（SPU） = 0.3 ： 1 and the m（dimethyl sulfate） ： m（SPU） =0.3 ： 1. The Zeta ootential of the oroduct is the 20 -40 mV.