摘要
采用热裂解气相色谱-质谱(Py-GC/MS)仪,对4种不同制备工艺的鲜天然橡胶(NR)[(NR-1)醋酸凝固鲜天然胶乳,(NR-2)微生物快速凝固鲜天然胶乳,(NR-3)微生物凝固乙醇胺混合鲜天然胶乳和(NR-4)自然凝固蛋白酶混合鲜天然胶乳]的生胶分子结构进行分析,主要鉴定其中的挥发性裂解产物,用气相色谱峰面积归一法测定各组分的相对百分含量,并对其定性结构进行比较。研究结果表明:在550℃裂解温度条件下,4种制备工艺NR生胶的裂解碎片都生成了顺式结构的1,3戊二烯单体(NR-1还生成了2-甲基1,3-丁二烯单体)的特征离子;同时也生成了大量的二聚体1-甲基-4-(1-甲基乙烯基)环己烯和1,4-二甲基4-乙烯基环己烯及三聚体β-蛇麻烯和甘葡环烃等,但它们的组成即相对百分含量存在差异。其细微结构的差别为:NR-3和NR-1都含有少量含氮杂环、羟基和羰基基团;NR-2结构较简单;NR-4含有氯甲酰氧基和羰基等。
The natural rubber（NR）samples,prepared by acetic acid coagulation of fresh latex,microbial rapad coagulation of fresh latex,microbial coagulation of fresh latex mixed with ethanolamine and natural coagulation of fresh latex with protease,referred to as NR-1,NR-2,NR-3 and NR-4 raw rubbers,were analyzed using a py-GC/MS method.The results showed that the major degradation product of the four NR raw rubber samples was 1-methyl-4-（methylethenyl）cyclohexene along with 1,3-pentadiene,（E）-（monomer）and groupings of compounds containing 15 and 20 carbon atoms（three and four monomers） units in the pyrolysate at 550 ℃.In addition,NR-1 raw rubber also generated 2-methyl-1,3-butadiene（monomer）;NR-3 and NR-1 raw rubbers both contained a small amount of heterocyclic with nitrogen atom,hydroxyl and carbonyl oxygen;the structure of NR-2 was relatively simple;while NR-4 contained chloroformyloxy-and carbonyl oxygen,and so on.
出处
《热带作物学报》
CSCD
2011年第7期1364-1371,共8页
Chinese Journal of Tropical Crops
基金
公益性行业(农业)科研专项经费资助项目(No.nyhyzx07-033-6)
海南省自然科学基金资助项目(No.807047)
关键词
NR
制备工艺
裂解气相色谱-质谱
结构分析
NR
Preparative processes
Pyrolysis-gas chromatography/mass spectrometry
Structure analysis
