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Environmental degradation and biofouling of ‘green’ plastics including short and medium chain length polyhydroxyalkanoates
Author(s) -
Woolnough Catherine A,
Yee Lachlan H,
Charlton Tim,
Foster L John R
Publication year - 2010
Publication title -
polymer international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.592
H-Index - 105
eISSN - 1097-0126
pISSN - 0959-8103
DOI - 10.1002/pi.2746
Subject(s) - rugosity , polyhydroxyalkanoates , biofouling , polymer , degradation (telecommunications) , biodegradable polymer , polymer chemistry , contact angle , polystyrene , chemistry , materials science , chemical engineering , organic chemistry , composite material , ecology , telecommunications , biochemistry , genetics , membrane , habitat , bacteria , computer science , engineering , biology
Biopolymers derived from natural resources are potential alternatives to recalcitrant synthetic plastics; however, studies investigating the degradability of these biopolymers in natural environments are relatively few. This study compares the environmental degradation of polymers described as ‘green plastics’ in garden soil in terms of weight loss, topographical changes and biofilm attachment. Poly(3‐hydroxybutyrate) (PHB) and poly[(3‐hydroxybutyrate)‐ co ‐(3‐hydroxyvalerate)] (P(HB‐ co ‐8HV)), (copolymer containing 8 mol% HV) films degraded rapidly, losing 50% of their initial weight in 50 days. In contrast, after burial for 380 days, the medium chain length polyhydroxyoctanoate (PHO) lost 60% of its weight, poly( D , L ‐lactide) (PDLL) 18% and poly[( D , L ‐lactide)‐ co ‐glycolide] (PDLLG) 35%. Polystyrene (PS) and ethyl cellulose (EC) showed no significant degradation. Both weight loss and biofouling occurred in the following sequence: P(HB‐ co ‐8HV) = PHB > PHO > PDLLG > PDLL > PS = EC. The surface rugosity and surface areas of PHB and P(HB‐ co ‐8HV) increased three‐ and twofold, respectively, during degradation, indicating surface erosion. The surface rugosity of PHO increased twofold and the surface area increased by 25%. This in situ study demonstrates a quantifiable relationship between biofilm attachment, surface rugosity and polymer degradation. PHB and P(HB‐ co ‐8HV) showed greater biofouling and increased surface rugosity, and degraded significantly faster than the other polymers studied. Copyright © 2009 Society of Chemical Industry