Preparation of Starch−Fatty Acid Modified Clay and Its Application in Packaging Papers.

To improve the bondability between clay filler and lignocellulosic fiber, Kaolin clay particles were modified using a starch−fatty acid complex method. The coating efficiency of starch on clay particle surfaces was investigated by measuring the dissolved starch in the supernatant. The experimental results indicated that more than 98% of the applied starch was precipitated onto the surface of the filler, and the resulting starch−fatty acid−clay composites had relatively good resistance against moderate shear force. The morphology, particle size, and ζ potential of the starch modified filler were also determined with scanning electron microscopy, Malvern particle size analyzer, and Malvern Zetasizer, respectively. An aqueous slurry of linerboard pulp containing 5−15 wt % modified fillers was used for handsheet preparation, and the effects of the addition of modified filler on the paper properties were studied. At a dosage of 10% of the modified filler (based on filler), the retention of the filler was higher than 75%. The strength properties of paper with starch modified fillers were improved by approximately 15% when compared against those of paper with unmodified fillers. [ABSTRACT FROM AUTHOR]