Branched poly(1,4-butylene carbonate-co-terephthalate)s:LDPE-like biodegradable semicrystalline thermoplastics
Branched poly(1,4-butylene carbonate-co-terephthalate)s:LDPE-like biodegradable semicrystalline thermoplastics
- 주제(키워드) condensation polymerization
- 발행기관 아주대학교
- 지도교수 이분열
- 발행년도 2015
- 학위수여년월 2015. 8
- 학위명 석사
- 학과 및 전공 일반대학원 분자과학기술학과
- 실제URI http://www.dcollection.net/handler/ajou/000000020320
- 본문언어 영어
- 저작권 아주대학교 논문은 저작권에 의해 보호받습니다.
초록/요약
Branched poly[1,4-butylene carbonate-co-terephthalate]s (PBCTs) have been synthesized by the addition of a small amount of trifunctional or tetrafunctional alcohol monomers [glycerol propoxylate (1) or pentaerythritol (2)] in the polycondensation of 1,4-butanediol, dimethyl carbonate, and dimethyl terephthalate and their thermal, mechanical and rheological properties have been investigated. The branched PBCT exhibited more pronounced toughness in tensile test while providing the advantage of processibility at high shear rates due to the pronounced shear thinning in melt. To avoid gel formation, the feed amount of 1 or 2 was carefully controlled at below 0.5 mol% for 1 and below 0.3 mol% for 2. When feed of 1 or 2 was used, a high-molecular-weight melt state (Mw ~180,000 g/mol) was reached in a total reaction time of 5.5?6.5 h with a yield higher than 90%. The generated PBCTs were a semicrystalline polymer (Tg ~5 °C and Tm ~120 °C) when the terephthalate content (F[TPA]) was 45?50 mol%. The crystallization rate increased with increasing F[TPA] and branch content (F[1 or 2]); PBCT composed of F[TPA] = 49 mol% and F[1] = 0.44 mol% was crystallized completely in a short time, ~3 min, at a crystallization temperature of 50 °C. The branched PBCT exhibited more pronounced toughness in tensile test while providing the advantage of processibility at high shear rates due to the pronounced shear thinning in melt. It was also found that the branched PBCTs were biodegradable by a buffer solution containing a lipase.
more목차
1. Introduction 1
2. Results and discussion 3
2. 1 Preparation of branched PBCT 3
2. 2 Thermal properties 9
2. 3 Rheological and mechanical properties 13
2. 4 Biodegradation studies 15
3. Conclusions 16
4. Experimental Section 18
4. 1 General remarks 18
4. 2 Preparation of branched PBCT (Table1, entry 9) 18
4. 3 Preparation on 160g scale (Table1, entry 16) 19
4. 4 Tensile studies 19
4. 5 Enzymatic degradation test 19
4. 6 Acknowledgements 20
5. Reference 20
6. Supporting information 25
