Effects of star-shaped PCL having different numbers of arms on the mechanical, morphological, and thermal properties of PLA/PCL blends

• Published in: Journal of polymer research Vol. 28; no. 1
• Main Author: Doganci, Merve Dandan
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 2021; Springer Nature B.V
• Subjects: Biodegradability; Chain mobility; Characterization and Evaluation of Materials; Chemical synthesis; Chemistry; Chemistry and Materials Science; Differential scanning calorimetry; Diisocyanates; Elongation; Fourier transforms; Functional groups; Industrial Chemistry/Chemical Engineering; Infrared analysis; Liquid chromatography; Mechanical properties; Miscibility; Molecular chains; NMR; Nuclear magnetic resonance; Polylactic acid; Polymer Sciences; Polymers; Ring opening polymerization; Spectrum analysis; Thermodynamic properties; Weight; Mechanical properties; Different arm length; PLA; Star-shaped PCL
• ISSN: 1022-9760; 1572-8935
• DOI: 10.1007/s10965-020-02380-2

In this work, a series of linear and star-shaped poly(ε-caprolactone)s (SPCL) with various arm numbers were successfully synthesized with ring-opening polymerization (ROP) with the initiators having different number of hydroxyl functional groups. The molecular characteristics of synthesized PCLs were analyzed via Fourier Transform Infrared Spectroscopy (FTIR), proton nuclear magnetic resonance spectra ( 1 H NMR), thermogravimetric analyzer (TGA), differential scanning calorimetry (DSC) and gel permeation chromatography (GPC) measurements. Then PCLs were melted with poly(lactic acid) (PLA) by utilizing a micro-compounder at a constant blending ratio (90/10% weight) and constant 1,4-phenylene diisocyanate (PDI) (1% weight) as a commercial compatibilizer. It was reported that adding SPCL improved mechanical properties of PLA. The three-armed star shaped PCL (3SPCL) caused significant decrease in modulus due to its high molecular chain mobility when compared linear, four- and six-armed PCLs. An increment was observed in the elongation at break values with incorporation of star polymers and it increased from 4 to 9%. Scanning electron microscopy (SEM) photos indicated that immiscibility of the two biodegradable polymers were enhanced and thus mechanical improvement were achieved.