Effect of prevulcanisation of natural rubber latex on the chemical and physical properties of latex thread

The effect of prevulcanisation on the processing properties and network structure of a series of latex compounds containing conventional and efficient vulcanisation (E.V. systems) systems for the manufacture of latex thread was evaluated. Prevulcanisation was effected at 70 degrees C and the extent of crosslinks formed and compound viscosity at various periods of heating were studied. It is observed that the vulcanisation systems studied have a profound effect on the extent of crosslink formation during prevulcanisation. The network structure of the vulcanisate was also studied and found the polysulphidic content is high as the extent of prevulcanisation of the latex compound increases. Latex threads were also prepared from typical latex compounds which were prevulcanised to different degrees and their chemical and physical properties were evaluated. It is observed that the extent of prevulcanisation affects the aged and unaged physical properties of latex threads