Investigating the properties of maleated poly(lactic acid) and its effect on poly(lactic acid)/cellulose nanofiber composites

Abstract

<jats:title>Abstract</jats:title><jats:p>In this research, maleated poly(lactic acid) (PLA-g-MA) was manufactured by different levels of maleic anhydride (MAH). Also PLA-g-MA effects as a compatibilizer were investigated on PLA/cellulose nanofiber (CNF) composites. The grafting reaction was performed in the presence of dicumyl peroxide (DCP) as an initiator at constant level (0.2 phr) via reactive extrusion. Furthermore, the effects of four different levels of MAH (1–4 phr) were studied on the physical properties of PLA grafted films. We used the Fourier transform infrared (FTIR) and titration methods for confirmation of the grafting process. Based on the titration method, the greatest amount of yield was gained by 4 phr of MAH in grafting. Contact angle analysis shows that increasing the amount of MAH led to a decrease in the contact angle of films. Moreover, the glass transition temperature (T<jats:sub>g</jats:sub>) and % crystallinity were decreased by increasing MAH content. PLA-g-MA was added to the composites in two levels of 3% and 5% in total. CNF was used at a constant level of 5%. The thermal, morphological and mechanical properties of nanocomposites were determined as a function of PLA-g-MA content using thermogravimetric analysis, heat distortion temperature (HDT) and tensile testing. All the prepared nanocomposite materials showed improvement in the mechanical and thermal properties compared to neat PLA.</jats:p>

Poly(Lactic Acid)-Based Graft Copolymers: Syntheses Strategies and Improvement of Properties for Biomedical and Environmentally Friendly Applications: A Review

“…Nevertheless, the results obtained for the compatibility of various PLA-based blends are significant. Examples of variations in mechanical properties are shown in Table 2 in blends of PLA/cellulose nanofibers (CNF) [24].…”

“…Nevertheless, the results obtained for the compatibility of various PLA-based blends are significant. Examples of variations in mechanical properties are shown in Table 2 in blends of PLA/cellulose nanofibers (CNF) [24]. The following paragraphs show the main PLA graft copolymers obtained from PLA-g-MA with their principal properties and applications.…”

“…The consequences of this poor interfacial compatibility between polymer and filler are poor properties of the final blend. The compatibilization of PLA/cellulosic derivatives blends to improve many of the blends' properties, especially mechanical properties, while maintaining a natural source, are the most widely described in the literature [24,25]. Because PLA-g-MA acts as a reactive compatibilizer, a PLA-g-cellulose copolymer is formed as a result of the reaction between the anhydride of PLA-g-MA, and alcohol functions of the cellulosic derivative (Figure 6) [21].…”

“…Because PLA-g-MA acts as a reactive compatibilizer, a PLA-g-cellulose copolymer is formed as a result of the reaction between the anhydride of PLA-g-MA, and alcohol functions of the cellulosic derivative (Figure 6) [21]. The presence of a very low percentage of PLA-g-MA (<1%) in the original blend significantly improved the properties of the blend [24]. Tensile strength, tensile modulus and strain at break were increased by 55.3%, 15.45% and 30.4%, respectively, over neat PLA by adding 5 wt.% of cellulose nanofibers (CNFs), and by 169.2%, 36.3% and 139.1%, respectively, by adding 5% of PLA-g-MA to the blend PLA/CNF.…”

Combined Effects of Cellulose Nanofiber Nucleation and Maleated Polylactic Acid Compatibilization on the Crystallization Kinetic and Mechanical Properties of Polylactic Acid Nanocomposite

“…Although CNF has gained substantial market interest as an alternative to inorganic nano-sized reinforcements in nanocomposite materials, the main challenge of using nanofiber is the difficulties of achieving good nanofiber dispersion in a non-polar medium due to their polar surfaces [ 35 ]. CNF has been shown to be compatible with PLA based on previous studies, but agglomeration was observed to occur at a certain amount of CNF, notably at higher loading.…”