In Situ High Aspect Ratio Development of Phosphate Glass Fillers in Polybutylene Succinate‐Based Composites

ABSTRACT Reinforcing polymers by incorporating fibers is a common practice in the polymer materials industry. However, the processing stages are sometimes complicated because of the flowing difficulties of the melt polymer filled with solid fibers of which the fraction is, in fact, limited. In this work, the feasibility of in situ creating a fibrillar phosphate glass (P‐glass) reinforcing phase in a polybutylene succinate (PBS) during the processing stage is demonstrated. This is ensured using a P‐glass of peculiarly low glass transition temperature. Thus, during the processing stages, in this case, injection molding and spinning, nodules are converted into fibrils or needles with a very high aspect ratio. However, particular caution must be taken to avoid the possible premature P‐glass crystallization that prevents its easy deformation afterwards. In practice, it is shown that the previous blending of P‐glass in PBS at ambient temperature in a powder form is much more efficient than melt blending to avoid this crystallization. As an important size issue, the possibility of producing yarns of PBS/P‐glass composite is also shown. The mechanical behavior of the obtained injected parts and yarns clearly exhibits the stiffening effect of the P‐glass filler, especially if the filler is of fibrillar shape. Nevertheless, whether on yarns or injected specimens, the presence of fillers unfortunately led to an important reduction of the deformation at break. To complete, the Halpin‐Tsai model was successfully applied to describe the Young modulus using filler aspect ratio values consistent with the morphological observations.