Cellulose diacetate (CDA) and calcium carbonate (CaCO3) biodegradable composites were prepared by melt mixing in a twin screw extruder and their physical properties were examined. In the melt processing, triacetine and epoxidized soybean oil were added to the composites as a plasticizer and lubricant, respectively. The optimal conditions for the preparation of the biodegradable composites were determined. Acetic acids (CH3COOH) were made by pyrolysis acetyl group (-OC(O)CH3) of CDA and TA in melt processing. Increasing the amount of CaCO3 in the composites resulted in further enhancement of the CH3COOH absorption effects. The tensile strength and elongation were decreased, and Young's modulus and Tg value increased with increasing amount of CaCO3.

생분해가 가능한 셀룰로오스 디아세테이트(CDA)/탄산칼슘(CaCO3) 복합체를 용융가공을 통하여 제조하였고, 그 특성을 연구하였다. 용융가공을 위하여, 혼합체에 가소제로 트리아세틴(TA)과 윤활제로서 소량의 에폭시화된 콩기름(epoxidized soybean oil)을 첨가하였으며 가공시 최적 조건을 확립하였다. CDA와 TA의 아세틸기(-OC(O)CH3)가 용융가공 중에 열분해 되어 초산(CH3COOH)을 발생시키는데, 탄산칼슘의 함량(wt%)이 증가할수록 초산(CH3COOH)의 흡수효과(absorption effects)가 향상되며, 탄성률과 Tg가 증가하였다. 탄산칼슘의 함량이 증가할수록 인장강도와 신율은 감소하였다.

Keywords: cellulose diacetate; calcium carbonate(CaCO3); triacetine; biodegradable