An extensive study on an origin of gel formation and storage hardening phenomena as a main reason for an inconsistency in properties of natural rubber, including an elucidation on an effective method to inhibit those phenomena
1. To investigate the role of non-rubber components such as proteins, fatty acid ester groups, carbohydrates and Mg2+ ions on storage hardening and change in physical properties, i.e.; Mooney viscosity and tensile properties during accelerated storage condition. The formation of gel and chemical change in NR during storage were also discussed to establish the possible mechanism for storage hardening of NR.
2. To investigate the effect of polar chemicals such as phenol, ethylene glycol and hydroxylamine, on gel formation, storage hardening and change in physical properties of NR during storage under the accelerated condition. Furthermore, an alternative effect of hydroxylamine on the storage hardening was proposed by inhibiting the formation of hydrogen bond at the branching point of rubber chain.
3. To elucidate on an effective method to inhibit the storage hardening phenomenon and give a well-defined consistent rubber.
