New application of poly(butylene succinate) (PBS) based ionomer as biopolymer: a role of ion group for hydroxyapatite (HAp) crystal formation

Sodium sulfonate ionic group bearing PBS ionomer (PBSi) and hydroxyapatite (HAp) composites were prepared by soaking in the simulated body fluid (SBF) solution, which is the biomimetic method, as well as the effects of the ionic group on the HAp crystal formation and growth were investigated. The introduced sodium sulfonate ionic groups operated as the functional groups with negative charge densities, which can bind plentiful Ca²⁺ ions efficiently, consequently serving as active sites allowing HAp crystals to grow on the surfaces of the PBSi matrix. By SEM analysis, it was observed that HAp became growing as the shape with the porous holes. These holes are thought to be very suitable for the ingrowths of the surrounding tissue and the assistance to the bone formation. Based on this finding, it can be clearly concluded that the ionic groups in the PBSi may be decisive factors in growing HAp, and it is anticipated that this novel materials can contribute to excellent biopolymer.