Correlation between solution relative viscosity and the microstructural properties of the poly(3-hydroxybutyrate-co-3-hydroxyvalerate) – PHBV solution blow spun mats

Abstract

In this study, we produced poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) fibrous mats via solution blow spinning (SBS) and evaluated their microstructural properties. We propose here the utilization of the theoretical estimative of relative viscosity (RV) as an independent variable in a statistical design of experiments (DoE) to account for the polymer’s molecular weight (Mw) effect on the determination of the diameter and morphology of the fibers. The RV of the solution (42.3・103–287.4・103) and air pressure – AP (70–140 kPa) were varied. The analysis of variance (ANOVA) indicated that the increase in RV favored an increment in fiber size and resistance to alignment. Higher AP produced aligned and thinner fibers with higher crystallinity. The spinnability regions were determined based on the estimated RV of the PHBV solutions and the AP levels. Fibers were formed at 70 kPa from solutions with RV ranging from 10・103 to 106, while at 140 kPa, from 42・103 to 106. Nanofibers were produced from less viscous solutions (RV = 42.3・103–124.4・103), while microfibers were produced from solutions with RV = 287.4・103. The developed ANOVA model predicted with good accuracy (R2adj. = 0.96) the average diameter of the PHBV fibers produced from the SBS technique using polymers with distinct Mw values, including those available in the literature data.

Keywords

• solution blow spinning (sbs)
• micro- and nanofibers
• processing technologies
• biodegradable polymers
• design of experiment (doe)
• biopolymer
• poly(hydroxy alcanoate)
• microfibers
• morphology
• nanofiber
• image processing
• viscosity