Table 4.

Summary of selective studies on the preparation, modification and morphology of natural fiber-reinforced PBS.

PBS/Natural Fiber Composites	Preparation Methods	Modification	Summary of the Results	Refs
PBS/alfa fiber	Compression molding method	Alkaline treatment	Fiber alkaline treatment resulted in: -Removal of pectin, lignin, waxes and hemicellulose. -Improved interfacial adhesion. -Fibers embedded into PBS matrix.	[126]
PBS/Cotton fiber	Compression molding at 150 °C for 5 min	Silane treatment	-Poor interfacial interaction in the absence of fiber treatment. -Improved interfacial adhesion due to fiber treatment.	[127]
PBS/rice straw fiber	Injection molding	Amino silane treated	Treatment of fibers with 3-(2-aminoethylaminopropyl)-trimethoxysilane (AEAPTMES) achieved the best interfacial bonding results.	[128]
PBS/Kenaf fiber (KF)	Melt mixing method	----------------	Fibers were embedded in the PBS matrix; however, there was a phase separation between kenaf and PBS.	[129]
PBS/Cellulose fiber (Cellulose extracted from kenaf fiber and commercial cellulose)	Melt mixing at 200 °C for 5 min	Hydrochloric acid (HCl) and sodium hydroxide (NaOH) treatment	-The morphology of the PBS/KTH, PBS/EC, and PBS/CC composites were reported. -In this study, KTH denotes kenaf treated with HCl, EC is the extracted cellulose fiber and CC stands for commercial cellulose. -All composites showed visible gaps between the fiber and matrix, due to poor interaction.	[130]
PBS/lignocellulosic fibers (coconut, sugarcane bagasse, curaua, sisal)	Thermo-pressing mold method	Ethanol and cyclohexane extraction process	-All composites, to some extent, showed voids and fiber pull outs; however, a better interaction between the two phases was reported. -The surface roughness of the curaua and sisal fibers promoted mechanical bonding between PBS and Fibers	[131]
PBS/ramie fiber Fabric (RFF)	Thermal compressive process	Treatment with 2% of 3 Triethoxysilylpropylamine (KH550)	-KH550 treated fibers were embedded into the PBS matrix due to improved interfacial bonding.	[132]
PBS/curaua fibers	Compression molding	Enzymatic treatment	-Homogenous distribution of untreated and treated fibers in the PBS matrix at 10 wt.% fiber loading. -Strong adhesion between the fiber and polymer matrix with no voids.	[133]
PBS/bamboo fiber	Hot press molding	Acetoxylation	-Presence of strong van der Waals and hydrogen-bond interactions as well as physical adsorption between functional groups of composites. -Tensile strength and the initial decomposition temperature of Acetylated-BF/PBS were improved by 18% and 12.2 °C, respectively, due to the fiber modification	[134]