The thermal stability of composites consisting of EFB/PLA, EFB/Kenaf/PLA, and EFB/Kenaf/MAH/PLA is evaluated and presented in Figure . A three-step deterioration process is visible in the TGA thermograms of the EFB/PLA and EFB/kenaf hybrid composites without coupling agent treatment. This first step starts at about 100°C and leads to the loss of water.