Starch‐MMT composite films: Effects of bio‐inspired modification on MMT

Abstract

Montmorillonite (MMT) was modified by bio-inspired polydopamine (PDA) to obtain an exfoliated structure. Then, the modified MMT (MMT-D) and the original MMT were incorporated into starch to fabricate individual composite films. MMT lamellae were mostly intercalated in starch, while those of MMT-D were more likely to be exfoliated and presented better dispersibility, as revealed by the surface morphologies and XRD patterns of the composite films. Although MMT provided greater thermal protection to starch, MMT-D improved the tensile properties of the composite films more effectively. The composite film containing 2% MMT-D displayed a tensile strength as high as 8.1 MPa and a Young's modulus as high as 416.4 MPa, which were 2.1 and 3.8 times the values of the pure starch film, respectively. However, the composite films containing MMT had reduced tensile strength and modulus. This study showed that PDA pre-modification of MMT could improve the performance of starch-based nanocomposites, thus accelerating their acceptance in food packaging applications.

Nanoclays in Food and Beverage Packaging

“…Several attempts have been made to improve the interface interactions of MMT-Na + and starch by many strategies such as addition of various plasticizers or hydrophilic premodification of MMT-Na + with cationic exchange [74]. Zhou and Xu [76] reported that surface modification of MMT-Na + with polydopamine (PDA) can improve the interface interactions between starch and nanoclay, resulting in an exfoliated structure and greater tensile strength and Young's modulus. While the unmodified MMT nanocomposite showed only the intercalated structure, it was believed that the catechol groups from PDA was prone to form hydrogen bonding with hydroxyl groups residing in the starch polymer chain.…”

Starch‐based composites using mature fine tailings as fillers

“…The MMT crystalline peaks are mostly absent in their composites (Figure ), proving that starch disrupts the crystalline order of pristine MMT, and also confirming the hypothesis we raised above when discussing the SEM micrographs of these composites. Special attention is paid to the peak at 2 θ = 9° because it determines interlayer distance . This translates in an interlayer distance of 0.98 nm for the MMT used in our composites.…”

Green Design of Novel Starch-Based Packaging Materials Sustaining Human and Environmental Health

“…Scientists designed nacre-mimetic artificial materials, especially in combination with clay (such as montmorillonite), exhibiting excellent mechanical properties and good thermal stability, for applications in food packaging [282] among others. Montmorillonite (MMT) is one of the most extensively utilized natural clay minerals due to its low-cost, good biocompatibility, high specific surface area, excellent TS and good thermal stability, and gas barrier properties [283,284]. MMT belongs to the smectite group, encompassing two fused siloxane tetrahedral sheets sandwiching an edge-shared octahedral sheet made up of aluminum or magnesium hydroxide [285].…”