Influence of stilbene acrylate quaternary ammonium salt optical brighteners on the properties of ground calcium carbonate and HDPE composite materials

Abstract

Background

Improving the dispersibility and compatibility of ground calcium carbonate particles in the polymer matrix, while enhancing whiteness, is the core issue of high-value ground calcium carbonate through adding efficient surface modifiers and whitening agents.

Methods

Stilbene acrylate quaternary ammonium salt optical brighteners 6a-d were synthesized and optimized with polyethylene glycol 300, sodium dodecyl sulfate, and sodium stearate to form integrated additives, which were used to whiten and modify ground calcium carbonate, and then was added to prepare high density polyethylene composite materials.

Significant Findings

The results showed that the whiteness of the processed ground calcium carbonate increased from 93.65 to 101.51, and the oil absorption value decreased from 32.4 g/100 g to 14.6 g/100 g. The filling amount of processed ground calcium carbonate reached 25 wt.% and the performance of composite materials had improved significantly. Especially, the whiteness of HDPE/6b-M-GCC increased by 24.63 %, the cold crystallization temperature increased by 1 °C, the crystallinity increased by 4.3 %, and the tensile strength increased by 13.69 %, respectively. The addition of OB 6b was beneficial for improving the compatibility between modified ground calcium carbonate and high density polyethylene, thereby effectively enhancing the performance of the composite materials.