Poly[(butylene succinate)-co-(butylene terephthalate)] copolymers containing 1-12 mol% of butylene terephthalate were synthesized. Their thermal and mechanical properties were investigated. Melting poing of poly(butylene succinate) (PBS) HOMOPOLYMER WAS 115.2 ℃ and that of the copolymer containing 12 mol% if byttkebe tereogtgakate was 96.7 ℃. The crystallinity of the copolymer was decreased from 56.1%(PBS homopolymer) to 41.2% (the copolymer containing 12 mol% of butylene terephthalate). Breaking stress of PBS homopolymer was 37.3 MPa and the value was increased with the addition of butylene terephthalate until it showed the maximum value of 47.0 MPa at the 6 mol% butylene terephthalate content: The breaking stresses of the other copolymers were also higher than trhat of the PBS homopolymer. Breaking strain of the copolymer was increased from 100 % for PBS homopolymer to 380% for a copolymer containing 12 mol% of butylene terephthalate.

Butylene succinate 성분이 1-12 mol% 포함된 poly[(butylene succinate)-co-(butylene terephthalate)] 공중합체를 합성하고 조성에 따른 열적 거동과 기계적 성질을 알아보았다. Poly(butylene succinate) (PBS) 단일중합체의 융점은 115.2 ℃였으나 butylene terephthalate 성분의 증가에 따라 감소하여 butylene terephthalate 12 mol% 첨가 시 융점이 96.7 ℃k지 감소함을 알 수 있었다. 시차주사열량계(DSC)로 측정된 ΔH_f(heat of fusion)에서 구한 %결정화도는 PBS 단일중합체가 56.1 %였으나, butylene terephthalate가 첨가되면 감소하기 시작해서 butylene terephthalate 12 mo.% 첨가 시 41.2 % 로 감소하였다. PBS 단일중합체의 절단강도는 37.3 MPa이었으나 butylene terephthalate가 첨가되면 증가하여 butylene terephthalate 6 mol%존재 시 최고값 (47.0 MPa)을 나타냈으며, 이 후 감소하였으나 PBS 단일중합체보다는 절단강도가 개선되었다. 이에 비해 절단신도는 PBS 단일중합체가 100%였고 butylene terephthalate의 양이 증가하면 점차 증가하여 butylene terephthalate 12 mol% 존재 시 최고 380%로 약 4배 정도 신도가 향상되었다.

Keywords: poly(butylene succinate); poly(butylene terephthalate); polyester copolymer; breaking stress; toughness