Specialty natural rubber latex foam: foamability study and fabrication process

Ramli, Roslim; Chai, Ai Bao; Ho, Jee Hou; Kamaruddin, Shamsul; Rasdi, Fatimah Rubaizah Mohd; De Focatiis, Davide S. A.

Abstract

Specialty natural rubber (SpNR) latex namely deproteinized natural rubber (DPNR) latex and epoxidized natural rubber (ENR) latex have been produced to meet specific product’s requirements. However, SpNR is normally used in the form of block rubber to manufacture dry rubber products such as tires and automotive parts. This study aims to diversify the applications of SpNR latex into latex foam products. This study found that, foamability of SpNR latex is lower compared to normal latex (LATZ), but shows longer stability time after foamed. This study also found that, foam collapse and foam coagulate are two main challenges in the fabrication process of SpNR latex foam. Despite these challenges, SpNR latex foam can be fabricated at different density levels. During the foaming process, additional foaming agent is required to fabricate a SpNR latex foam, which is different from fabricating a normal NR latex foam, especially at low latex foam density. Consequently, a higher level of sodium silicofluoride, used as the gelling agent, is required to set the cell structure of the foam. This study also found that, foam density influenced the gelling time and volume shrinkage of the SpNR latex foam. In this work, an ideal compounding, foaming and gelling formulation to fabricate SpNR latex foam via Dunlop batch foaming process have been developed. Morphological study showed that all latex foams are open-cell structure, with lower density foam exhibits higher porosity and mean pore size. Comparison on hysteresis behavior between DPNR and ENR latex foam indicated that, ENR latex foam exhibits higher hysteresis loss ratio compared to DPNR latex foam.

Citation

Ramli, R., Chai, A. B., Ho, J. H., Kamaruddin, S., Rasdi, F. R. M., & De Focatiis, D. S. A. (2022). Specialty natural rubber latex foam: foamability study and fabrication process. Rubber Chemistry and Technology, 95(3), 492-513. https://doi.org/10.5254/rct.21.78938

• Journal Article Type: Article
• Acceptance Date: Oct 23, 2021
• Online Publication Date: Dec 27, 2021
• Publication Date: 2022-07
• Deposit Date: Oct 25, 2021
• Publicly Available Date: Dec 27, 2021
• Journal: Rubber Chemistry and Technology
• Print ISSN: 0035-9475
• Electronic ISSN: 1943-4804
• Publisher: Rubber Division, ACS
• Peer Reviewed: Peer Reviewed
• Volume: 95
• Issue: 3
• Pages: 492-513
• DOI: https://doi.org/10.5254/rct.21.78938
• Keywords: Materials Chemistry; Polymers and Plastics
• Public URL: https://nottingham-repository.worktribe.com/output/6536121
• Publisher URL: https://meridian.allenpress.com/rct/article-abstract/doi/10.5254/rct.21.78938/475834/SPECIALTY-NATURAL-RUBBER-LATEX-FOAM-FOAMABILITY?redirectedFrom=fulltext
• Additional Information: This document is the Accepted Manuscript version of a Published Work that appeared in final form in Rubber Chemistry & Technology, copyright © Rubber Division, ACS after peer review and technical editing by the publisher. To access the final edited and published work see https://doi.org/10.5254/rct.21.78938