Ribbon-like microfiber of vulcanized and non-vulcanized natural rubber obtained by the solution blow spinning

Authors: SOUSA, ELIRALDRIN - Universidade Estadual Paulista (UNESP); SANCHES, ALEX OTÁVIO - Universidade Estadual Paulista (UNESP); VILCHES, JOSÉ LUIZ - Universidade Estadual Paulista (UNESP); SILVA, MICHAEL JONES - Universidade Estadual Paulista (UNESP); McMahan, Colleen; MALMONGE, JOSÉ ANTONIO - Universidade Estadual Paulista (UNESP)

Submitted to: European Polymer Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/16/2024
Publication Date: 2/8/2024
Citation: Sousa, E.A., Sanches, A., Vilches, J., Silva, M., McMahan, C.M., Malmonge, J. 2024. Ribbon-like microfiber of vulcanized and non-vulcanized natural rubber obtained by the solution blow spinning. European Polymer Journal. 35(2).Article e6306. https://doi.org/10.1002/pat.6306.
DOI: https://doi.org/10.1002/pat.6306

Interpretive Summary: Natural rubber microfibers are biobased materials produced from a solution blow spinning technique. These ribbonlike structures are soft and flexible, and their porosity properties make them good candidates for use in wound healing and many other applications. In this work, microfibers were produced with and without chemical crosslinkers. Adding the crosslinkers resulted in much stronger fibrous films but with the microfiber morphology intact. The process described operates at higher rates than previously reported, and has flexibility to engineer microfibrous natural rubber membranes with tunable size, strength, porosity, and solubility. Production of self-supporting membranes, with elasticity and porosity, opens up possibilities for new applications such as sensors or small molecule delivery devices which can be targeted to engineered properties of NR microfibers.

Technical Abstract: Natural rubber microfibers were obtained from natural rubber/chloroform solutions with or without vulcanization agents, by a solution blowing spinning technique (SBS). The microfibers showed a ribbon-like morphology with average widths ranging from 15 µm to 45 µm, depending on the processing conditions. Microfibrous NR membranes incorporating vulcanizing agents were treated at temperatures of 70, 80 and 90 °C for 1, 2, 3 and 4 hours. Membrane tensile strength and elongation at break varied with temperature and treatment time. The best result was found with the sample treated at 90 ºC for 3 hours. In this case the tensile strength and elongation at break was (4.9 ± 0.8) MPa and (867 ± 18) % which is about 310% and 330% higher than the values found for the same sample without the incorporation of vulcanizing agents. This expressive increase is attributed to the vulcanization of the rubber, which also provided a shift to a higher value of the glass transition temperature.