Open AccessOptimizationof poly(L-lactide)-polybutylene adipate terephthalate diblockcopolymer by ring opening polymerization
Author(s) -
Dutchanee Pholharn,
Yottha Srithep
Publication year - 2019
Publication title -
iop conference series. materials science and engineering
Language(s) - English
Resource type - Journals
eISSN - 1757-899X
pISSN - 1757-8981
DOI - 10.1088/1757-899x/526/1/012026
Subject(s) - adipate , materials science , polymer chemistry , polymerization , differential scanning calorimetry , lactide , gel permeation chromatography , ring opening polymerization , polybutylene terephthalate , polymer , crystallinity , copolymer , polyester , chemical engineering , composite material , physics , engineering , thermodynamics
Polylactide (PLA) is a brittle biodegradable polymer: co-bonding of a higher flexibility polymer such as polybutylene adipate terephthalate (PBAT) into the PLA chains has been shown to make it more flexible. We studied the optimum conditions for synthesizing poly(L-lactide)-polybutylene adipate terephthalate diblock copolymer (PLLA- b -PBAT), with ratios by weight of L-lactide:PBAT from 100:0.3 to 100:1. Incubation times of polymerization were varied from 4 to 8 hours at 160°C. Nuclear magnetic resonance (NMR) spectra were used to verify the structure of synthesized polymers. Differential scanning calorimetry thermograms showed melting temperatures of diblock copolymers at around 161-168°C - characteristic of PLA. The optimum conditions for PLLA- b -PBAT synthesis by ring opening polymerization were 100:0.3 ratio and eight hour incubation leading to 95% yield, a high degree of crystallinity (71%) and the highest molecular weight (34,000g/mol, measured by gel permeation chromatography).