Effects of TiO2 on Melt Strength Properties of Polymeric Materials, 2001 Polymers Laminations & Coatings Conference Proceedings

S. Atalar--The objective of this paper is to investigate the effects of TiO2 on melt strength of low density polyethylene.

Melt strength is an important characteristic in polymer fabrication processes such as strand pelletization, blown film, thermoforming, blowmolding, melt spinning and others. TiO2, which is dispersed in the polymer to provide opacification and pigmentation, may have a varying effect on the processing melt strength of the polymer.

Using Statistical Method ANOVA (Analysis of Variance), we analyzed the melt strength of polyethylene as a function of TiO2 concentration and dispersion states. We investigated the effect of 2 levels of TiO2 particle size, 4 levels of concentration and 2 levels of dispersion states as a 2 X 4 X 2 level ANOVA.

Concentration has been found to have the greatest effect, increasing the melt strength up to a critical concentration and decreasing thereafter. The dispersion factor also had a statistically significant effect with good dispersing pigment giving higher melt strength values. Larger particle size pigment gave slightly higher melt strength value at lower concentrations than the smaller one, but was less significant than dispersion and concentration.