1. CSIR, Materials Science and Manufacturing, Polymers and Composites, Nonwovens and Composites Research Group PO Box 1124, Port Elizabeth, 6000, South Africa,
2. CSIR, Materials Science and Manufacturing, Polymers and Composites, Nonwovens and Composites Research Group PO Box 1124, Port Elizabeth, 6000, South Africa and Department of Textile Science, Nelson Mandela Metropolitan University Port Elizabeth, South Africa