丙烯海松酸的合成研究

通过松香与丙烯酸的Diels-Alder加成反应制备了丙烯海松酸,考察了原料摩尔比对反应的影响。实验结果表明,随着丙烯酸用量的增加,产物的酸值和软化点逐步升高至不变;紫外光谱研究发现,随着丙烯酸用量的增长,枞酸型树脂酸相对含量下降,而海松酸型树脂酸的含量未见显著变化;气相色谱-质谱联用分析显示,在松香树脂酸与丙烯酸的加成反应中,树脂酸中的海松酸、异海松酸、脱氢枞酸等不参与反应,而长叶松酸、枞酸和新枞酸异构化为左旋海松酸,与丙烯酸发生加成反应;即使丙烯酸过量,长叶松酸和枞酸转化率最高也只可以达到91%和86%;研究还发现,加成产物丙烯海松酸有二种构造异构体,分别占丙烯海松酸量的20%和80%。

Study on the synthesis of acrylpimaric acid

Acrylpimaric acid was synthesized by Diels-Alder adductive reaction of rosin and acrylic acid.The molar ratio of rosin acid and acrylic acid how to influence the reaction was studied.It was found that the acid number and softening point of products were gradually increased with the increase of dosage of acrylic acid,until the arrival of equal mole ratio of acrylic acid and resin acid.The UV-VIS result showed that the abietic acid content in the final products was gradually decreased,while the pimaric resin acid content kept constant during the reactions.GC-MS analyzing result showed that pimaric acid,isopimaric acid,dehydroabietic acid in the rosin didn’t participated in the adductive reaction;and palustric acid,abietic acid,neoabietic acid were isomerized into leoopimaric acid firstly,then took part in the adductive reaction with acrylic acid.The final conversion of longifolene acid and abietic acid were only 91% and 86% respectively even acrylic acid exceeded the demand of the reaction.It was also demonstrated that acrylpimaric acid has two isomers with relatively proportion of 20% and 80% respectively in the adductive production.