Biodegradable Coco Peat‐Reinforced <scp>PLA</scp> / <scp>PBS</scp> Mulch Films: Enhanced Moisture Retention and <scp>UV</scp> ‐Induced Degradation for Sustainable Agriculture

ABSTRACT Conventional polyethylene mulch films cause serious environmental concerns, driving the search for sustainable biopolymer alternatives. In this study, cocopeat, a lignocellulosic agro‐waste, was incorporated into a Polylactic acid/Polybutylene succinate (PLA/PBS, 75:25 wt%) blend to improve soil‐moisture retention and photodegradability. Cocopeat loading (0–7 phr) significantly affected film performance. The water‐vapor transmission rate decreased from 160 g m −2 day −1 for neat PLA to 132 g m −2 day −1 for the PLA/PBS blend and rose slightly to 152 g m −2 day −1 at 7 phr cocopeat. Tensile strength remained above 28 MPa at 3–5 phr loading, while swelling capacity increased to 2.7%, indicating better water retention. After 360 h of UV exposure, the carbonyl index increased by about 35% in films containing 7 phr cocopeat, confirming faster photodegradation. Fourier‐transform infrared analysis showed hydrogen bonding between polymer carbonyl and filler hydroxyl groups, supported by scanning electron microscopy that revealed uniform filler dispersion at low concentrations. Overall, films containing 3–5 phr cocopeat achieved an optimal balance of strength, moisture regulation, and degradability, representing a promising biodegradable alternative to polyethylene mulch films for sustainable agriculture.