{"title":"Ring-opening polymerization of <i>ε</i>-caprolactone initiated by tin(II) octoate/<i>n</i>-hexanol: DSC isoconversional kinetics analysis and polymer synthesis.","authors":"Winita Punyodom, Wanich Limwanich, Puttinan Meepowpan, Boontharika Thapsukhon","doi":"10.1080/15685551.2021.1908657","DOIUrl":null,"url":null,"abstract":"<p><p>The kinetics of ring-opening polymerization (ROP) of <i>ε</i>-caprolactone (<i>ε</i>-CL) initiated by 1.0, 1.5 and 2.0 mol% of stannous(II) octoate/<i>n</i>-hexanol (Sn(Oct)<sub>2</sub>/<i>n</i>-HexOH) wase successfully studied by non-isothermal differential scanning calorimetry (DSC) at heating rates of 5, 10, 15 and 20 °C/min. The DSC polymerization kinetic parameters of <i>ε</i>-CL were calculated using differential (Friedman) and integral isoconversional methods (Kissinger-Akahira-Sunose, KAS). The average activation energy (<i>E<sub>a</sub></i> ) values obtained from Friedman and KAS methods were in the range of 64.9-70.5 kJ/mol and 64.9-80.4 kJ/mol, respectively. The values of frequency factor (<i>A</i>) were determined from model fitting method using Avrami-Erofeev reaction model. The average values of <i>A</i> for the ROP of <i>ε</i>-CL initiated by 1.0, 1.5 and 2.0 mol% of Sn(Oct)<sub>2</sub>/<i>n</i>-HexOH (1:2) were 7.3x10<sup>7</sup>, 2.8x10<sup>6</sup> and 1.2x10<sup>6</sup> min<sup>-1</sup>, respectively. From kinetics studied, the polymerization rate of <i>ε</i>-CL increased with increasing initiator concentration. The performance of Sn(Oct)<sub>2</sub>/<i>n</i>-HexOH in the synthesis of poly(<i>ε</i>-caprolactone) (PCL) was investigated by bulk polymerization at temperatures of 140, 160 and 180 °C. Sn(Oct)<sub>2</sub>/<i>n</i>-HexOH (1:2) could produce high number average molecular weight ( <math> <mover> <mrow><msub><mi>M</mi> <mrow><mrow><mi>n</mi></mrow> </mrow> </msub> </mrow> <mo>‾</mo></mover> </math> = 9.0 × 10<sup>4</sup> g/mol) and %yield (89%) of PCL in a short period of time at Sn(Oct)<sub>2</sub> concentration of 0.1 mol% and temperature of 160°C. The mechanism of the ROP of <i>ε</i>-CL with Sn(Oct)<sub>2</sub>/<i>n</i>-HexOH was proposed through the coordination-insertion mechanism.</p>","PeriodicalId":11170,"journal":{"name":"Designed Monomers and Polymers","volume":null,"pages":null},"PeriodicalIF":1.8000,"publicationDate":"2021-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/15685551.2021.1908657","citationCount":"6","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Designed Monomers and Polymers","FirstCategoryId":"92","ListUrlMain":"https://doi.org/10.1080/15685551.2021.1908657","RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"POLYMER SCIENCE","Score":null,"Total":0}
引用次数: 6
Abstract
The kinetics of ring-opening polymerization (ROP) of ε-caprolactone (ε-CL) initiated by 1.0, 1.5 and 2.0 mol% of stannous(II) octoate/n-hexanol (Sn(Oct)2/n-HexOH) wase successfully studied by non-isothermal differential scanning calorimetry (DSC) at heating rates of 5, 10, 15 and 20 °C/min. The DSC polymerization kinetic parameters of ε-CL were calculated using differential (Friedman) and integral isoconversional methods (Kissinger-Akahira-Sunose, KAS). The average activation energy (Ea ) values obtained from Friedman and KAS methods were in the range of 64.9-70.5 kJ/mol and 64.9-80.4 kJ/mol, respectively. The values of frequency factor (A) were determined from model fitting method using Avrami-Erofeev reaction model. The average values of A for the ROP of ε-CL initiated by 1.0, 1.5 and 2.0 mol% of Sn(Oct)2/n-HexOH (1:2) were 7.3x107, 2.8x106 and 1.2x106 min-1, respectively. From kinetics studied, the polymerization rate of ε-CL increased with increasing initiator concentration. The performance of Sn(Oct)2/n-HexOH in the synthesis of poly(ε-caprolactone) (PCL) was investigated by bulk polymerization at temperatures of 140, 160 and 180 °C. Sn(Oct)2/n-HexOH (1:2) could produce high number average molecular weight ( = 9.0 × 104 g/mol) and %yield (89%) of PCL in a short period of time at Sn(Oct)2 concentration of 0.1 mol% and temperature of 160°C. The mechanism of the ROP of ε-CL with Sn(Oct)2/n-HexOH was proposed through the coordination-insertion mechanism.
期刊介绍:
Designed Monomers and Polymers ( DMP) publishes prompt peer-reviewed papers and short topical reviews on all areas of macromolecular design and applications. Emphasis is placed on the preparations of new monomers, including characterization and applications. Experiments should be presented in sufficient detail (including specific observations, precautionary notes, use of new materials, techniques, and their possible problems) that they could be reproduced by any researcher wishing to repeat the work.
The journal also includes macromolecular design of polymeric materials (such as polymeric biomaterials, biomedical polymers, etc.) with medical applications.
DMP provides an interface between organic and polymer chemistries and aims to bridge the gap between monomer synthesis and the design of new polymers. Submssions are invited in the areas including, but not limited to:
-macromolecular science, initiators, macroinitiators for macromolecular design
-kinetics, mechanism and modelling aspects of polymerization
-new methods of synthesis of known monomers
-new monomers (must show evidence for polymerization, e.g. polycondensation, sequential combination, oxidative coupling, radiation, plasma polymerization)
-functional prepolymers of various architectures such as hyperbranched polymers, telechelic polymers, macromonomers, or dendrimers
-new polymeric materials with biomedical applications