The Study Of Starch Modified Ground Calcium Carbonate Encapsulation Performance

Modifying filler with Starch to improve its using properties has been a hot research field. In this paper, GCC was modified by starch with the aid of sodium stearate and sodium hexametahposphate. The utilization rate of complexes in the modification was effectively used and the Modified GCC got a good anti-shear ability by the control of modification condition.Firstly, the modification condition was studied in this paper. With optical properties and Strength Properties as the appraisal index, every experimental factor was discussed and found the four influential factors. Orthogonal experiment was designed by the four influential factors. Results showed that when the dosage of sodium hexametahposphate was 1.5%(based on GCC), the concentration of blend was 20%(based on GCC), the precipitation temperature was 60℃ and the stirring rate was 200 rpm, the Modified GCC performed well in the filled papers.Secondly, the anti-shear ability of Modified GCC and the utilization rate of complexes were studied. Results showed that a lower precipitation temperature and more sodium hexametahposphate were beneficial to improve the anti-shear ability of Modified GCC and the utilization rate of complexes. However, the more dosage of sodium hexametahposphate not means the higher utilization rate of composite. The highest utilization rate of composite was got when the dosage of sodium hexametahposphate was 1.5%.Thirdly, the character of Modified GCC was compared with Unmodified GCC. The result showed that the whiteness and opacity of Modified GCC was lower than Unmodified GCC. The Zeta potential of GCC was turned positive value to negative value after the modification. The size of Modified GCC was about 6 times than Unmodified GCC and the consistency was about 1/11 of the latter.Lastly, the contrast experiment of Modified GCC papers and Unmodified GCC paper was studied in this part. Results showed that Modified GCC papers performed much better than Unmodified GCC papers in paper strength properties and fiber bonding strength at the same ash content. While, the optical properties of Modified GCC Papers were lower than Unmodified GCC Papers. The opacity of Modified GCC Papers and Unmodified GCC Papers was reducing, especially of Modified GCC papers, when the ash content was more than a certain level. With the increase of loading, at first, the retention of Modified GCC was higher than Unmodified GCC, and then in turn when filler amount up to about 42%. With the increasing dosage of CPAM, the retention of Modified GCC was lower than Unmodified GCC at first, then in turn at later. Finally, the modification could significantly improve the sizing effect of AKD.