Open Access

ARTICLE

Biobased Additives as Biodegradability Enhancers with Application in TPU-Based Footwear Components

Isabel Patrícia Fernandes¹, Mariana Barbosa¹, Joana Soares Amaral², Vera Pinto³, José Luís Rodrigues³, Maria José Ferreira³, Maria Filomena Barreiro^1*
1 Laboratory of Separation and Reaction Engineering (LSRE), Associate Laboratory LSRE/LCM, Polytechnic Institute of Bragança, Campus Santa Apolónia Ap. 1134, 5301-857 Bragança, Portugal
2 REQUIMTE-LAQV, Rua Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal and Polytechnic Institute of Bragança, Campus de Santa Apolónia Ap 1134, 5301-857 Bragança, Portugal
3 Portuguese Footwear Technological Centre (CTCP), Rua de Fundões - Devesa Velha, 3700-121 S. João-da-Madeira, Portugal
*Corresponding author:

Journal of Renewable Materials 2016, 4(1), 47-56. https://doi.org/10.7569/JRM.2015.634126

Abstract

Among the wide variety of materials employed in the manufacture of shoes, thermoplastic polyurethanes (TPUs) are one of the most widely used. Given its widespread use, and associated waste management problems, the development of more biodegradable and evironmentally compatible solutions is needed. In this work, a polyester-based TPU used in the footwear industry for outsoles production was modifi ed by compounding with lignin, starch and cellulose at content of 4% (w/w). The biodegradability was evaluated by using agar plate tests with the fungi Aspergillus niger ATCC16404, the Gram-negative bacteria Pseudomonas aeruginosa ATCC9027 and an association of both (consortium), and soil tests at 37 °C and 58 °C. The obtained results evidenced a positive effect of the tested biobased additives, the most favourable results being registered with lignin. These results were corroborated by the structural modifi cations observed by FTIR analysis. Additionally, mechanical tests prove the suitability of using the lignin modifi ed TPUs for footwear outsoles production.

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Keywords

Thermoplastic polyurethanes, biodegradation, compounding, biobased additives

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