Tags

Type your tag names separated by a space and hit enter

Enzymatic preparation of novel thermoplastic di-block copolyesters containing poly[(R)-3-hydroxybutyrate] and poly(epsilon-caprolactone) blocks via ring-opening polymerization.
Biomacromolecules 2008; 9(7):1883-93B

Abstract

Enzymatic modification of a microbial polyester was achieved by the ring-opening polymerization of epsilon-caprolactone (CL) with low-molecular weight telechelic hydroxylated poly[(R)-3-hydroxybutyrate] (PHB-diol) as initiator and Novozym 435 (immobilized Candida antarctica Lipase B) as catalyst in anhydrous 1,4-dioxane or toluene. The ring-opening polymerization was investigated at different conditions with two different types of PHB-diols: PHB-diol(P), containing a primary OH and a secondary OH end groups, and PHB-diol(M), consisting of 91% PHB-diol(P) and 9% PHB-diol containing two secondary OH end groups. The reactions were followed by GPC analyses of the resulting polymers at different time points, and the optimal conditions were established to be 70 degrees C at a weight ratio of CL/enzyme/solvent of 8:1:24. The ring-opening polymerization of CL with PHB-diol(M) (Mn of 2380, NMR) at the molar ratio of 50:1 under the optimal conditions in 1,4-dioxane gave the corresponding poly[HB(56 wt %)-co-CL(44 wt %)] with Mn (NMR) of 3900 in 66% yield. Polymerization of CL and PHB-diol(P) (Mn of 2010, NMR) at the same condition in toluene gave the corresponding poly[HB(28 wt %)-co-CL(72 wt %)] with Mn (NMR) of 7100 in 86% yield. Both polymers were characterized by (1)H and (13)C NMR and IR analyses as di-block copolyesters containing a PHB block with a secondary OH end group and a poly(epsilon-caprolactone) (PCL) block with a primary OH end group. NMR analyses and control experiments suggested no formation of random copolymers and no change of the PHB block during the reaction. The enzymatic ring-opening polymerization was selectively initiated by the primary OH group of PHB-diol, whereas the secondary OH group remained as an end group in the final polymers. The thermal properties of the di-block poly(HB-co-CL)s were analyzed by DSC, with excellent T g values for the elastomer domain: poly[HB(56 wt %)- co-CL(44 wt %)] with M n (NMR) of 3900 demonstrated a T g of -57 degrees C, Tm of 145, 123, and 53 degrees C; and poly[HB(28wt%)-co-CL(72wt%)] with Mn (NMR) of 7100 gave a Tg of -60 degrees C, Tm of 147 and 50 degrees C. Thus, the selective enzymatic ring-opening polymerization with PHB-diol as macro-initiator provides a new method for the preparation of PHB-based block copolymers as biomaterials with good thermoplastic properties and novel structures containing functional end groups.

Authors+Show Affiliations

Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, Singapore.No affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

18540675

Citation

Dai, Shiyao, and Zhi Li. "Enzymatic Preparation of Novel Thermoplastic Di-block Copolyesters Containing poly[(R)-3-hydroxybutyrate] and Poly(epsilon-caprolactone) Blocks Via Ring-opening Polymerization." Biomacromolecules, vol. 9, no. 7, 2008, pp. 1883-93.
Dai S, Li Z. Enzymatic preparation of novel thermoplastic di-block copolyesters containing poly[(R)-3-hydroxybutyrate] and poly(epsilon-caprolactone) blocks via ring-opening polymerization. Biomacromolecules. 2008;9(7):1883-93.
Dai, S., & Li, Z. (2008). Enzymatic preparation of novel thermoplastic di-block copolyesters containing poly[(R)-3-hydroxybutyrate] and poly(epsilon-caprolactone) blocks via ring-opening polymerization. Biomacromolecules, 9(7), pp. 1883-93. doi:10.1021/bm8001396.
Dai S, Li Z. Enzymatic Preparation of Novel Thermoplastic Di-block Copolyesters Containing poly[(R)-3-hydroxybutyrate] and Poly(epsilon-caprolactone) Blocks Via Ring-opening Polymerization. Biomacromolecules. 2008;9(7):1883-93. PubMed PMID: 18540675.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Enzymatic preparation of novel thermoplastic di-block copolyesters containing poly[(R)-3-hydroxybutyrate] and poly(epsilon-caprolactone) blocks via ring-opening polymerization. AU - Dai,Shiyao, AU - Li,Zhi, Y1 - 2008/06/10/ PY - 2008/6/11/pubmed PY - 2008/9/23/medline PY - 2008/6/11/entrez SP - 1883 EP - 93 JF - Biomacromolecules JO - Biomacromolecules VL - 9 IS - 7 N2 - Enzymatic modification of a microbial polyester was achieved by the ring-opening polymerization of epsilon-caprolactone (CL) with low-molecular weight telechelic hydroxylated poly[(R)-3-hydroxybutyrate] (PHB-diol) as initiator and Novozym 435 (immobilized Candida antarctica Lipase B) as catalyst in anhydrous 1,4-dioxane or toluene. The ring-opening polymerization was investigated at different conditions with two different types of PHB-diols: PHB-diol(P), containing a primary OH and a secondary OH end groups, and PHB-diol(M), consisting of 91% PHB-diol(P) and 9% PHB-diol containing two secondary OH end groups. The reactions were followed by GPC analyses of the resulting polymers at different time points, and the optimal conditions were established to be 70 degrees C at a weight ratio of CL/enzyme/solvent of 8:1:24. The ring-opening polymerization of CL with PHB-diol(M) (Mn of 2380, NMR) at the molar ratio of 50:1 under the optimal conditions in 1,4-dioxane gave the corresponding poly[HB(56 wt %)-co-CL(44 wt %)] with Mn (NMR) of 3900 in 66% yield. Polymerization of CL and PHB-diol(P) (Mn of 2010, NMR) at the same condition in toluene gave the corresponding poly[HB(28 wt %)-co-CL(72 wt %)] with Mn (NMR) of 7100 in 86% yield. Both polymers were characterized by (1)H and (13)C NMR and IR analyses as di-block copolyesters containing a PHB block with a secondary OH end group and a poly(epsilon-caprolactone) (PCL) block with a primary OH end group. NMR analyses and control experiments suggested no formation of random copolymers and no change of the PHB block during the reaction. The enzymatic ring-opening polymerization was selectively initiated by the primary OH group of PHB-diol, whereas the secondary OH group remained as an end group in the final polymers. The thermal properties of the di-block poly(HB-co-CL)s were analyzed by DSC, with excellent T g values for the elastomer domain: poly[HB(56 wt %)- co-CL(44 wt %)] with M n (NMR) of 3900 demonstrated a T g of -57 degrees C, Tm of 145, 123, and 53 degrees C; and poly[HB(28wt%)-co-CL(72wt%)] with Mn (NMR) of 7100 gave a Tg of -60 degrees C, Tm of 147 and 50 degrees C. Thus, the selective enzymatic ring-opening polymerization with PHB-diol as macro-initiator provides a new method for the preparation of PHB-based block copolymers as biomaterials with good thermoplastic properties and novel structures containing functional end groups. SN - 1526-4602 UR - https://www.unboundmedicine.com/medline/citation/18540675/Enzymatic_preparation_of_novel_thermoplastic_di_block_copolyesters_containing_poly[_R__3_hydroxybutyrate]_and_poly_epsilon_caprolactone__blocks_via_ring_opening_polymerization_ L2 - https://dx.doi.org/10.1021/bm8001396 DB - PRIME DP - Unbound Medicine ER -