Scale formation is a major problem in the oil and gas industry. Through different production processes seawater and formation water mix. The minerals present in each cause sparingly soluble salts to precipitate and deposit. This scale formation can if left untreated block pipelines, damage equipment and cause production and revenue loss. Scale inhibitors are chemicals designed to prevent or delay scale build-up and are the most common way to combat this issue. Inhibitors containing phosphonate are particularly effective and are the focus of this study.Ball milling reactions and mechanochemistry are relatively new and promising approaches to chemical synthesis. They offer unique opportunities in unlocking new reactions, improving efficiency, and steering the industry as a whole towards a greener approach to synthesis. They allow for the exclusion of bulk solvents, in addition to cutting down reaction times. In this study, ball milling was successfully used to synthesise phosphonate-based scale inhibitors using a solvent-free version of the Moedritzer-Irani reaction with no additional acid. The synthesised compounds were tested against calcite and gypsum scale. Phosphonated chitosan (PC) has showed very promising results in inhibition performance, thermal stability, and calcium compatibility.