Well-defined organic–inorganic core–shell structure IPN-P(AA-co-AM) polymer spheres by modified suspension polymerization

Organic–inorganic interpenetrating network poly (acrylic acid- co -acrylamide) IPN-P(AA-co-AM) polymer sphere with core–shell structure has been synthesized by modified suspension polymerization, which the core is high cross-linked and shell is light cross-linked, respectively. The dispersed phase (water phase) and continuous phase (oil phase), as well as core and shell crosslinking agent are screened based on the water absorption capacity of the polymer spheres. In addition, SiO 2 is applied to endow polymer spheres with excellent thermal and water absorption properties. FTIR, TG, SEM, and XPS analyze the chemical structure, thermal properties, morphology and surface element of polymer spheres, respectively. Particularly, the forming mechanism of polymer spheres and water absorption dynamic model are discussed in detail. The results show that the Organic–inorganic IPN-P(AA-co-AM) polymer spheres are successfully synthesized. The polymer spheres could be wrapped effectively when the SiO 2 content up to 2%. Compared to polymer spheres without SiO 2 , the thermal stability is greatly improved. The optimum core and shell crosslinking agent are pentaerythritol triacrylate (PETA) and sodium alginate, respectively. The maximum absorption capacity of polymer spheres for distilled water and 0.9wt% sodium chloride can up to 922.22 g/g and 93.87 g/g, respectively. Finally, the water absorption of IPN-P(AA-co-AM) polymer spheres dynamic model is closed to second-order.