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Storage hardening and “abnormal” groups in guayule rubber
Author(s) -
Angulo–Sanchez J. L.,
Jimenez–Valdez L. L.,
Campos–Lopez E.
Publication year - 1981
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.1981.070260508
Subject(s) - natural rubber , hevea brasiliensis , hevea , hardening (computing) , mooney viscosity , materials science , viscosity , composite material , chemistry , copolymer , polymer , layer (electronics)
Abstract The hardening process of natural ( Hevea brasiliensis ) rubber, that takes place when this rubber is stored in dry conditions over long periods of time, has been correlated with the presence of reactive “abnormal” groups directly grafted on the polymeric chain and in the serum of the latex. In the present work, natural Hevea (HR) and Guayule ( Parthenium argentatum ) rubber (GR) were stored under accelerated conditions and the changes in Mooney viscosity and molecular weight measured. The results showed that while HR undergoes hardening, GR keeps its Mooney viscosity constant, as does a constant viscosity (CV) Hevea rubber. These results are explained by the absence of functional “abnormal” groups that sustain the hardening reactions.