Conventional crosslinked polymers and homopolymers both have their own limitations. As a result, core-shell polymer was synthesized to obtain cauliflower-shaped and highly hydroxyl functionalized polymer. For the core, acrylate-based copolymers were synthesized by varying crosslinkers and porogens at different crosslink density. Owing to high surface area (554 m 2 /g), poly(MMA-co-DVB) was used as a core and low-molecular weight (24,600 g/mol) poly(GMA) was used as a shell in core-shell approach. Average particle sizes of the core polymers were in the range of 15-75 μm. In order to evaluate reactivity efficiency of core-shell polymer, hydroxyl content was evaluated with a value of 3.97 mmol/ g. Importantly, hydroxyl content demonstrated the successful increase in reactive sites of the core-shell polymer over conventional crosslinked hydroxyl polymer. Notably, synthesized core-shell polymer has more surface area and pore volume which substantially attributes for better polymer efficiency during application. Scanning electron microscopy images revealed the spherical, uniform, and slightly conglomerated properties of core-shell polymer. Due to higher reactivity, insolubility, and more surface area of hydroxyl functionalized core-shell polymer, its use become inevitably essential.