使用二氧化碳作为羰基化试剂,与己二胺反应生成相应的中间体,加入脱水剂和中间体反应得到HDI,考察了反应温度,加脱水剂前、后的反应时间,以及不同脱水剂对收率的影响.采用化学滴定法测定其收率,对合成产物进行了红外光谱表征.结果表明,HDI合成的最佳工艺条件为:n(脱水剂)∶n(HDA)=1.5∶1,反应温度5℃,以焦硫酸为脱水剂,焦硫酸加入前反应时间40 min,焦硫酸加入后反应时间50 min.在此条件下,HDI的收率为71.2％.%Methacrylic acid higher alcohols esters were synthesized from the raw materials of metha-crylic acid and higher alcohols. The obtained product was further reacted with vinyl acetate by esterifi-cation to form the target product. The optimum process conditions of esterification reactions got from single factor and orthogonal experiment are as follows: the mole ratio of acid and alcohol is 1. 2 : 1; the dosage of catalyst (mass fraction) is l%;the dosage of solvents is 40 mL;the esterification time is 2 hours. The optimum process conditions of polymerization reactions are as follows; the dosage of vinyl acetate quantity is 30%(mass fraction); the dosage of initiator(BPO)is 0. 75% (mass fraction) polymerization temperature is 70 ℃; the polymerization time is 4 hours. Determination shows that the product can reduce the pour point by 7 ℃.
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