Transparency and thermal insulation performance of LDH/LLDPE composite films designed based on Si-O-M covalent bond interfaces

Linear low-density polyethylene (LLDPE) films have garnered significant attention. However, their poor thermal insulation properties and limited functionality severely restrict applications. This study prepared an LDH/LLDPE composite film (LD-1.5%K) with excellent optical properties and high-performance infrared insulation by blending γ-(methacryloyloxy) propyltrimethoxysilane (KH570) dry-modified layered double hydroxide (D200) with LLDPE. D200 exhibits a refractive index close to LLDPE. Its incorporation significantly reduces the average infrared transmittance of LLDPE films. Surface modification of D200 with KH570 promotes uniform blending with LLDPE. As a result, the LD-1.5%K film delivers outstanding optical properties (high visible light average transmittance of 90.8%, and low haze of 23.5%) The film also achieves low infrared average transmittance. This low infrared transmittance endows LD-1.5%K film with excellent heat retention (up to 4°C) and recyclable stability. Consequently, this approach promotes crop growth and offers good economic value. Applying LD-1.5%K in areas with strong ultraviolet radiation and cold climates is effective. It provides a promising solution for future cultivation in harsh environments.