松节油催化热异构产物的气相色谱-质谱分析

用气相色谱-质谱联用技术(GC-MS)对Pd/C催化剂上松节油直接催化热异构的反应产物进行了分析鉴定,共分离出46个峰,鉴定出43个化合物,其中主要产物为单环单萜烯苧烯、α-焦烯、1,3,5,5-四甲基-1,3-环己二烯、无环单萜烯3,4-二甲基-2,4,6-辛三烯、2,6-二甲基-2,4,6-辛三烯、双环单萜烯莰烯、单环单萜烃对伞花烃,其相对质量分数分别为:57.87%、2.92%、1.45%、5.59%、7.15%、2.78%、3.39%。分析鉴定结果表明,松节油在Pd/C催化剂上发生开环异构生成单环单萜为主反应,并伴随深度开环异构、分子间氢转移、水合重排等副反应,倍半萜只发生极少量的异构化反应,蒎烯转化率为90.04%,蒎烯可高选择性地开环热异构制备单环单萜苧烯,苧烯选择性为73.17%。

Analysis of Chemical Constituents in the Reaction Products of Catalytic Thermal Isomerization of Turpentine by GC-MS

By GC-MS,46 peaks were separated and 43 compounds were identified from the reaction products of catalytic thermal isomerization of turpentine.The main products are limonene,α-pyronene,1,3,5,5-tetramethyl-1,3-cyclohexadiene(monocyclic monoterpenes),3,4-dimethyl-2,4,6-octatriene,2,6-dimethyl-2,4,6-octatriene(acyclic monoterpenes),camphene(bicyclic monoterpene)and p-cymene(monocyclic monoterpenoid),relative contents of which are 57.87%,2.92%,1.45%,5.59%,7.15%,2.78% and 3.39% respectively.The analysis results show that the ring-opening isomerization of bicyclic terpene pinene to monocyclic terpene limonene is the main reaction.Simultaneously,some accompanying side reactions such as further ring-opening isomerization,intermolecular hydrogen transfer reaction and aquated rearrangement reaction take place.Very few isomerization of sesquiterpene was observed.The conversion of pinene was 90.04% and selectivity for limonene reached 73.17%.