Natural Rubber Composites With Dual Mechanical and Antioxidant Properties Enabled by Orange Peel Hydrolyzates

ABSTRACT Orange peel is rich in cellulose, lignin, and natural antioxidants. In this work, an alkaline hydrolysis method combined with an in situ dispersion strategy was employed to treat orange peel powder (OPP). Subsequently, the hydrolyzed orange peel (HOP) dispersion was incorporated into natural rubber (NR) latex. NR composites were prepared: antioxidant‐free (NR‐xN) and with antioxidant 4010NA (NR‐x), varying HOP content (x phr). The static and dynamic mechanical properties, crosslink density, and thermo‐oxidative aging resistance of NR/HOP composites were tested. The results indicated that HOP serves as a significant reinforcing agent and antioxidant for NR. Notably, the addition of 2 phr of HOP to NR (NR‐2) resulted in a 32% increase in tensile strength compared to the control sample (NR‐0), reaching 34.5 MPa. After thermo‐oxidative aging (100°C, 24 h), the aged NR‐2 sample achieved a tensile strength of 20.8 MPa, representing a remarkable 201% increase over NR‐0. Crosslink density, tube model, and DMA analyses indicated HOP restricts NR chain mobility and enhances energy dissipation. HOP primarily interacts with NR chains mainly via physical entanglement; chemical crosslinking decreased with increasing HOP. This approach offers novel perspectives for developing high‐performance bio‐based rubber composites.