Pyrolysis GC-MS Study of Natural Rubber for Different Preparative Processes
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.