Ainul Kahfi Muhlasin, Poppy Puspitasari, Avita Ayu Permanasari, Dieter Rahmadiawan, Hairul Abral, Diki Dwi Pramono
Biodegradable polymer films with improved surface, thermal, and UV-protective properties are increasingly needed for sustainable packaging and protective material applications. In this study, polyvinyl alcohol (PVA) and gambir extract were combined to develop biocomposite films through drying without heating and with different heating durations of 10, 20, and 40 min. The heating duration effect on the morphology, elemental composition, functional groups, crystallinity, wettability, porosity, thermal behavior, and optical properties of the films were systematically investigated. Surface morphology analysis revealed that the sample with 40 min heating duration exhibited a smoother and more homogeneous surface than the unheated film. Elemental analysis confirmed that all films were mainly composed of carbon and oxygen, while Fourier transform infrared analysis showed similar functional group patterns for all samples. The crystallinity index increased with increasing heating duration, indicating enhanced structural ordering. Water contact angle measurements showed that longer heating durations reduced the hydrophilic nature of the films, with the 40 min-heated sample exhibiting the highest contact angle. In addition, this sample showed a smaller average pore diameter, lower glass transition temperature, higher enthalpy of fusion at melting temperature, and higher thermal decomposition temperature. Optical analysis further demonstrated that the PVA/gambir films provided good UV protection, particularly in the UV-B region. Overall, increasing the heating duration, especially to 40 min, improved the physicochemical, thermal, and optical performance of the PVA/gambir biocomposite films. © 2026, Science Society of Thailand under Royal Patronage. All rights reserved.
Department of Mechanical and Industrial Engineering, Faculty of Engineering, Universitas Negeri Malang, East Java, Malang, 65145, Indonesia; Nanomaterials Engineering Research Center, Universitas Negeri Malang, East Java, Malang, 65145, Indonesia; Department of Mechanical Engineering, Universitas Negeri Padang, Sumatera Barat, Padang, 25173, Indonesia; Laboratory of Nanoscience and Technology, Department of Mechanical Engineering, Andalas University, Sumatera Barat, Padang, 25163, Indonesia; Research Collaboration Center for Nanocellulose, BRIN-Andalas University, Padang, 25163, Indonesia
