Synthesis of Poly(Lactic Acid-<i>co</i>-Glycolic Acid) Copolymers with High Glycolide Ratio by Ring-Opening Polymerisation
The rise in demand for biodegradable plastic packaging with high barrier properties has spurred interest in poly(lactic acid-<i>co</i>-glycolic acid) (PLGA) copolymers with a relatively high glycolide content. In this work, we examined how reaction conditions affect the synthesis of PLGA...
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| Format: | Article |
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MDPI AG
2021-07-01
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| Series: | Polymers |
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| Online Access: | https://www.mdpi.com/2073-4360/13/15/2458 |
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| author | Alastair Little Alan M. Wemyss David M. Haddleton Bowen Tan Zhaoyang Sun Yang Ji Chaoying Wan |
| author_facet | Alastair Little Alan M. Wemyss David M. Haddleton Bowen Tan Zhaoyang Sun Yang Ji Chaoying Wan |
| author_sort | Alastair Little |
| collection | DOAJ |
| description | The rise in demand for biodegradable plastic packaging with high barrier properties has spurred interest in poly(lactic acid-<i>co</i>-glycolic acid) (PLGA) copolymers with a relatively high glycolide content. In this work, we examined how reaction conditions affect the synthesis of PLGA25 (L:G 25:75) through the ring-opening polymerisation of <span style="font-variant: small-caps;">d</span>-<span style="font-variant: small-caps;">l</span>-lactide (L) and glycolide (G), using tin 2-ethylhexanoate (Sn(Oct)<sub>2</sub>) as the catalyst and 1-dodecanol as the initiator. The effects of varying the initiator concentration, catalyst concentration, reaction time, and temperature on the molecular weight, monomer conversion, and thermal properties of PLGA25 were investigated. Increasing the reaction temperature from 130 to 205 °C significantly reduced the time required for high monomer conversions but caused greater polymer discolouration. Whilst increasing the [M]:[C] from 6500:1 to 50,000:1 reduced polymer discolouration, it also resulted in longer reaction times and higher reaction temperatures being required to achieve high conversions. High M<sub>n</sub> and M<sub>w</sub> values of 136,000 and 399,000 g mol<sup>−1</sup> were achieved when polymerisations were performed in the solid state at 150 °C using low initiator concentrations. These copolymers were analysed using high temperature SEC at 80 °C, employing DMSO instead of HFIP as the eluent. |
| first_indexed | 2024-03-10T09:09:52Z |
| format | Article |
| id | doaj.art-1f66d937e8e143b1929c9a00938388dc |
| institution | Directory Open Access Journal |
| issn | 2073-4360 |
| language | English |
| last_indexed | 2024-03-10T09:09:52Z |
| publishDate | 2021-07-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Polymers |
| spelling | doaj.art-1f66d937e8e143b1929c9a00938388dc2023-11-22T06:03:11ZengMDPI AGPolymers2073-43602021-07-011315245810.3390/polym13152458Synthesis of Poly(Lactic Acid-<i>co</i>-Glycolic Acid) Copolymers with High Glycolide Ratio by Ring-Opening PolymerisationAlastair Little0Alan M. Wemyss1David M. Haddleton2Bowen Tan3Zhaoyang Sun4Yang Ji5Chaoying Wan6International Institute for Nanocomposites Manufacturing (IINM), WMG, University of Warwick, Coventry CV4 7AL, UKInternational Institute for Nanocomposites Manufacturing (IINM), WMG, University of Warwick, Coventry CV4 7AL, UKDepartment of Chemistry, University of Warwick, Coventry CV4 7AL, UKPJIM Polymer Scientific Co., Ltd., Shanghai 201102, ChinaPJIM Polymer Scientific Co., Ltd., Shanghai 201102, ChinaPJIM Polymer Scientific Co., Ltd., Shanghai 201102, ChinaInternational Institute for Nanocomposites Manufacturing (IINM), WMG, University of Warwick, Coventry CV4 7AL, UKThe rise in demand for biodegradable plastic packaging with high barrier properties has spurred interest in poly(lactic acid-<i>co</i>-glycolic acid) (PLGA) copolymers with a relatively high glycolide content. In this work, we examined how reaction conditions affect the synthesis of PLGA25 (L:G 25:75) through the ring-opening polymerisation of <span style="font-variant: small-caps;">d</span>-<span style="font-variant: small-caps;">l</span>-lactide (L) and glycolide (G), using tin 2-ethylhexanoate (Sn(Oct)<sub>2</sub>) as the catalyst and 1-dodecanol as the initiator. The effects of varying the initiator concentration, catalyst concentration, reaction time, and temperature on the molecular weight, monomer conversion, and thermal properties of PLGA25 were investigated. Increasing the reaction temperature from 130 to 205 °C significantly reduced the time required for high monomer conversions but caused greater polymer discolouration. Whilst increasing the [M]:[C] from 6500:1 to 50,000:1 reduced polymer discolouration, it also resulted in longer reaction times and higher reaction temperatures being required to achieve high conversions. High M<sub>n</sub> and M<sub>w</sub> values of 136,000 and 399,000 g mol<sup>−1</sup> were achieved when polymerisations were performed in the solid state at 150 °C using low initiator concentrations. These copolymers were analysed using high temperature SEC at 80 °C, employing DMSO instead of HFIP as the eluent.https://www.mdpi.com/2073-4360/13/15/2458poly(lactic-<i>co</i>-glycolic acid)poly(glycolic acid)poly(lactic acid)ring-opening polymerisationhigh temperature GPCbiodegradable polymers |
| spellingShingle | Alastair Little Alan M. Wemyss David M. Haddleton Bowen Tan Zhaoyang Sun Yang Ji Chaoying Wan Synthesis of Poly(Lactic Acid-<i>co</i>-Glycolic Acid) Copolymers with High Glycolide Ratio by Ring-Opening Polymerisation Polymers poly(lactic-<i>co</i>-glycolic acid) poly(glycolic acid) poly(lactic acid) ring-opening polymerisation high temperature GPC biodegradable polymers |
| title | Synthesis of Poly(Lactic Acid-<i>co</i>-Glycolic Acid) Copolymers with High Glycolide Ratio by Ring-Opening Polymerisation |
| title_full | Synthesis of Poly(Lactic Acid-<i>co</i>-Glycolic Acid) Copolymers with High Glycolide Ratio by Ring-Opening Polymerisation |
| title_fullStr | Synthesis of Poly(Lactic Acid-<i>co</i>-Glycolic Acid) Copolymers with High Glycolide Ratio by Ring-Opening Polymerisation |
| title_full_unstemmed | Synthesis of Poly(Lactic Acid-<i>co</i>-Glycolic Acid) Copolymers with High Glycolide Ratio by Ring-Opening Polymerisation |
| title_short | Synthesis of Poly(Lactic Acid-<i>co</i>-Glycolic Acid) Copolymers with High Glycolide Ratio by Ring-Opening Polymerisation |
| title_sort | synthesis of poly lactic acid i co i glycolic acid copolymers with high glycolide ratio by ring opening polymerisation |
| topic | poly(lactic-<i>co</i>-glycolic acid) poly(glycolic acid) poly(lactic acid) ring-opening polymerisation high temperature GPC biodegradable polymers |
| url | https://www.mdpi.com/2073-4360/13/15/2458 |
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