Fabrication of bio-based polymer microcapsule containing fragrances via interfacial photo-initiated crosslinking

Home fragrance (F) products such as laundry detergent and fabric softener use fragrance or essential oils as key components. Typically, the fragrance is enclosed within a polymer. The shell enhances the longevity of the scent due to its durability. However, there is growing environmental concern about utilizing fossil polymers, which decompose slowly and harm the ecology and food chain. Biopolymers are also highly expected to be used as alternative polymers to prepare environmentally friendly microcapsules. This research aims to use poly cinnamyl methacrylate (PCMA) as a biopolymer to prepare microcapsules encapsulated fragrance via interfacial photo-initiated crosslinking. The CMA monomer was prepared by the esterification of cinnamyl alcohol with methacrylic anhydride and synthesized via radical polymerization to form PCMA with a molecular weight of 6,400 g/mol. The PCMA and PCMA/F particles were obtained when the PCMA and PCMA/F droplets dispersed in water were UV-irradiated at 60 W for 8h, giving PCMA and PCMA/F particles contained the highest crosslinking (60–75%). Both PCMA and PCMA/F particles were spherical and smooth outer surfaces where their particle sizes of ∼2 and 7 µm for PCMA and PCMA/F particles were obtained, respectively. The larger size of PCMA/F particles was due to encapsulation, where the encapsulation efficiency of fragrance in PCMA/F particles was approximately 100%. Moreover, the fragrances remaining in the microcapsule particles after 40 days of storage were over 90%. This technique was simple, had high potential microencapsulation, and was environmentally friendly, so the developed microcapsules would express great potential for textiles and laundry formulations.