Abstract
To improve the interfacial adhesion and dispersion of a poplar fiber in a polylactic acid (PLA) matrix, maleic anhydride (MA) and a silane coupling agent (KH550) were used to modify the poplar fiber. The poplar fiber/PLA composites were produced with different modifier contents. The mechanical, thermal, rheological, and physical properties of composites were investigated. A comparison of different natural fiber modifications on the properties of composites was also analyzed. The results showed that both MA and KH550 could improve the interfacial adhesion between the poplar fiber and PLA, resulting in the enhanced mechanical properties of the composite, with 17% and 23% increases of tensile strength for 0.5% MA and 2% KH550, respectively. The thermal properties of the composites were improved at 6% KH550 (a 9% enhancement of T90%) and decreased at 0.5% MA (a 6% decrement of T90%). The wettability of the composites obtained a 11.3% improvement at 4% KH550 and a 5% reduction at 4% MA. Therefore, factors such as mechanical properties, economic efficiency, and durability should be carefully considered when choosing the modifier to improve the property of the composite.
Highlights
With the petroleum crisis growing, biocomposites, such as natural fiber-reinforced polyesters, have been extensively applied in structural and non-structural areas [1,2]
The chemical components of the poplar fiber significantly changed after maleic anhydride (MA) and KH550 modification (Figure 2a)
For the MA-modified poplar fiber, the intensity at 1730 cm−1, which was caused by the carbonyl groups (C=O) in the poplar fiber, enhanced with the increasing of the MA content, and a new peak attributed to the carbon–carbon double bond (C=C) in MA was observed at 1610 cm−1 [27]
Summary
With the petroleum crisis growing, biocomposites (which are produced from natural resources), such as natural fiber-reinforced polyesters, have been extensively applied in structural and non-structural areas [1,2]. Physical treatment (such as thermal treatment [19]), chemical modification (such as acylation), and coupling agents are used to modify natural fibers and improve their compatibility with polymers. Throughout all these methods, chemical modification, especially maleated and silane modification, has become a popular choice because of its beneficial results [1]. A silane coupling agent (such as KH550) has been commonly applied in the composite to improve the interfacial adhesion between fibers and the polymer through an ester-exchange reaction between the silane and hydroxyl groups of the fibers; the mechanical properties of composites have been found to be enhanced, and the serving life of composites has been found to be extended [1,22]. The mechanical, thermal, and rheological properties and the wettability of the composites were analyzed
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
