Effect of calcium hydroxide filler on the mechanical properties of natural rubber latex films

Calcium hydroxide dispersion was prepared by reacting calcium chloride (cacl2) with sodium hydroxide (naoh),at room temperature for one hour. the resulting dispersion was added to prevulcanised natural rubber latex compound in different amounts. the effects of calcium hydroxide loading on the viscosity of the prevulcanised latex,the crosslinking density of the latex films,tensile properties and tear strength of normal,leached and aged coagulant dipped films were investigated. results showed that viscosity of the compound decreased when calcium hydroxide was added. the modulus at 100% elongation and at 300% elongation increased with calcium hydroxide loading. the tensile and tear strengths increased up to 10 p.h.r. of calcium hydroxide loading and then decreased again. the elongation at break,on the other hand,was not significantly affected by calcium hydroxide loading. the normal films showed properties in between that of the leached and aged films. sem micrographs showed formation of agglomerates as calcium hydroxide content was increased.