*2.2. Composite Preparation*

The PLA resin and pulp fibers were dried at 80 ◦C for 5 h under vacuum. PLA/pulp fiber composites were manufactured according to two methods (Figure 1): (1) Pulp fiber (NPF), epoxidized Tung oil and PLA were mixed directly; (2) epoxidized Tung oil soaked pulp fibers (SPF) were mixed with PLA (Sce. To soak the pulp fibers with epoxidized Tung oil, epoxidized Tung oil was dissolved in methyl ethyl ketone (ratio of 1/20) and sprayed onto the pulp. After that, the mixtures were dried in an oven at 80 ◦C for 5 h for the reaction between Tung oil and pulp fiber to take place.

**Figure 1.** Two fabricating methods for Poly (lactic acid) (PLA)/pulp fiber (PF) composites.

The separated pulp fibers and epoxidized Tung oil or epoxidized Tung oil-soaked pulp fibers were melt-blended with PLA resin in an internal mixer model Plastograph® EC (Duisburg, Germany) at 150 ◦C with a rotor speed of 50 rpm for 6 min. The pulp fiber/PLA composites were compressed and moulded into 3-mm-thick plates on a GoTech hot press at 170 ◦C at a pressure of 50 psi for 5 min. Moulded samples were cut into specimens according to ASTM D638 and ISO 178 to determine tensile properties and flexural properties respectively. To study the effect of pulp fiber contents on the properties of composite, the pulp fibers were adding into PLA with different fiber contents (0%, 10%, 20%, 30%, 40% and 50%) in the presence of epoxidized Tung oil (in amount of 10% of fiber). To study the effect of pulp fiber contents on the properties of composite, the used epoxidized Tung oil contents were 0%, 5%, 7.5%, 10%, 15%, respectively.
