Effects of talcum powder in coatings
As a filler talcum powder, the effect of elastic elongation and anti-pull of waterproof coatings are similar: with the increase of fillers, the elastic elongation and tensile strength of waterproof coatings are volatile, both first show growth, reach each peak, show the maximum value, and then show a decreasing trend, to achieve a stable presents the best value.
From the molecular point of view to consider: when the amount of talcum powder is very small, no talcum powder particles scattered into the middle of the large molecular chain segment, so can not reduce the attraction between the large molecular chain segment, the macromolecule chain segment is difficult to move, so that the elasticity of waterproof coating is small,With the increase of the amount of talcum powder, its small particles will be constantly filled between the macromolecule chain segments, the movement of the chain segment is strengthened, the elasticity elongation will increase, when the inorganic small particles of talcum powder just fill the gap between the large molecular chain, at this time the waterproof coating curing system has the least shortcomings, at this time the tensile strength and elongation of waterproof paint reached the best value.
If too much talcum powder is filled, it weakens the force between the macromolecules, reducing the cohesion of waterproof coatings, so that the tensile strength is reduced.
