Influence of Short Central PEO Segment on Hydrolytic and Enzymatic Degradation of Triblock PCL Copolymers

Journal Article · Fri Jun 15 04:00:00 EDT 2018 · Journal of Polymers and the Environment

DOI:https://doi.org/10.1007/S10924-017-1130-2· OSTI ID:22788127

Ponjavic, Marijana; Nikolic, Marija S. ^[1]; Jeremic, Sanja; Djokic, Lidija; Nikodinovic-Runic, Jasmina ^[2]; Cosovic, Vladan R. ^[3]; Djonlagic, Jasna ^[1]

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1. University of Belgrade, Faculty of Technology and Metallurgy (Serbia)
2. University of Belgrade, Institute of Molecular Genetics and Genetic Engineering (Serbia)
3. University of Belgrade, Institute of Chemistry, Technology and Metallurgy (Serbia)

Hydrolytic, enzymatic degradation and composting under controlled conditions of series of triblock PCL/PEO copolymers, PCEC, with central short PEO block (M{sub n} 400 g/mol) are presented and compared with homopolymer (PCL). The PCEC copolymers, synthesized via ring-opening polymerization of ε-caprolactone, were characterized by {sup 1}H NMR, quantitative {sup 13}C NMR, GPC, DSC and WAXS. The introduction of the PEO central segment (< 2 wt%) in PCL chains significantly affected thermal degradation and crystallization behavior, while the hydrophobicity was slightly reduced as confirmed by water absorption and moisture uptake experiments. Hydrolytic degradation studies in phosphate buffer after 8 weeks indicated a small weight loss, while FTIR analysis detected changes in crystallinity indexes and GPC measurements revealed bulk degradation. Enzymatic degradation tested by cell-free extracts containing Pseudomonas aeruginosa PAO1 confirmed high enzyme activity throughout the surface causing morphological changes detected by optical microscopy and AFM analysis. The changes in roughness of polymer films revealed surface erosion mechanism of enzymatic degradation. Copolymer with the highest content of PEO segment and the lowest molecular weight showed better degradation ability compared to PCL and other copolymers. Furthermore, composting of polymer films in a model compost system at 37 °C resulted in significant degradation of the all synthesized block copolymers.

• OSTI ID: 22788127
• Journal Information: Journal of Polymers and the Environment, Journal Name: Journal of Polymers and the Environment Journal Issue: 6 Vol. 26; ISSN 1566-2543
• Country of Publication: United States
• Language: English

Related Subjects

77 NANOSCIENCE AND NANOTECHNOLOGY
ATOMIC FORCE MICROSCOPY
COMPOSTING
COPOLYMERS
ENZYME ACTIVITY
FILMS
INFRARED SPECTRA
MOLECULAR WEIGHT
MORPHOLOGICAL CHANGES
NUCLEAR MAGNETIC RESONANCE
OPTICAL MICROSCOPY
PLASMA SWITCHES
SURFACES