Health & Environmental Research Online (HERO)


Print Feedback Export to File
5339881 
Journal Article 
Origin of characteristic properties of natural rubber - Synergistic effect of fatty acids on crystallization of cis-1,4-polyisoprene .1. Saturated and unsaturated fatty acids 
Kawahara, S; Nishiyama, N; Kakubo, T; Tanaka, Y 
1996 
1 
Rubber Chemistry and Technology
ISSN: 0035-9475
EISSN: 1943-4804 
69 
4 
600-607 
WOS:A1996VY53200003 
The influence of stearic acid, linoleic acid and their methylesters on crystallization or synthetic cis-1,4-polyisoprene was investigated at the isothermal crystallization temperature of -25 degrees C by means of differential scanning calorimetry and dilatometry. The overall crystallization rate of cis-1,4-polyisoprene increased in step with increasing stearic acid content, while the glass transition temperature of cis-1,4-polyisoprene did not change with the additive level. The addition of 1 wt% stearic acid or methyl stearate showed an acceleration effect on the initial crystallization of the polymer, while 1 wt% linoleic acid or methyl linoleate suppressed the initial crystallization. Coexistence of stearic acid and linoleic acid or stearic acid and methyl linoleate in cis-1,4-polyisoprene gave rise to a dramatic increase in the overall crystallization rate of the polymer. The characteristic properties of natural rubber were revealed to be related to the specific ratio of miscible fatty acids to immiscible fatty acids in natural rubber.