000			01333nam a2200157Ia 4500
008			220216s9999 xx 000 0 und d
100			_aClaramma N M
245		0	_aEffect of temperature on sulfur prevulcanization of natural rubber latex
260			_bJournal of Applied Polymer Science _c1997
300			_a1913-1920
520			_aSulfur prevulcanization of natural rubber latex was conducted at 60, 70, 80, and 90 C for different periods. The extent of crosslinking was assessed. Tensile properties, water absorption, leaching, and stress-relaxation characteristics of the films were also evaluated. The volume fraction of rubber (Vr), which is a measure of crosslink density of the films, showeed a maximum when prevulcanization was conducted at 80 C for 2h or at 90 C for 1h. At lower temperatures, the rate of reaction was slow. At each temperature, tensile strength and elongation at break decreased when the prevulcanization time increased, whereas the modulus increased up to a maximum crosslinking and thereafter decreased. Water absorption and leaching were more rapid in prevulcanized film than in postvulcanized film. The rate of stress relaxation slightly increased as the extent of prevulcanization increased.
650			_aNatural rubber latex
650			_aPrevulcanization
700			_aMathew N M
942			_cJS
999			_c58193 _d58193