Impact of the Incorporation of Nano-Sized Cellulose Formate on the End Quality of Polylactic Acid Composite Film

Abstract

Polylactic acid (PLA) films with good sustainable and biodegradable properties have been increasingly explored recently, while the poor mechanical property of PLA limits its further application. Herein, three kinds of nano-sized cellulose formate (NCF: cellulose nanofibril (CNF), cellulose nanocrystal (CNC), and regenerated cellulose formate (CF)) with different properties were fabricated via a one-step formic acid (FA) hydrolysis of tobacco stalk, and the influence of the properties of NCF with different morphologies, crystallinity index (CrI), and degree of substitution (DS) on the end quality of PLA composite film was systematically compared. Results showed that the PLA/CNC film showed the highest increase (106%) of tensile strength compared to the CNF- and CF-based films, which was induced by the rod-like CNC with higher CrI. PLA/CF film showed the largest increase (50%) of elongation at the break and more even surface, which was due to the stronger interfacial interaction between PLA and the CF with higher DS. Moreover, the degradation property of PLA/CNF film was better than that of other composite films. This fundamental study was very beneficial for the development of high-quality, sustainable packaging as an alternative to petroleum-based products.

Preparation of Antibacterial Dialdehyde Nanocellulose Using LiBr·3H2O Non-Dissolving Pretreatment Promoted Periodate Oxidation

“…XRD was used to further investigate the crystalline structure of cellulose after LBTH non-dissolving pretreatment. As shown in Figure e, the XRD patterns of cellulose samples without LBTH pretreatment showed typical peaks at 14.8, 16.5, and 22.6°, which were consistent with peaks of cellulose Iβ. , On the other hand, the XRD patterns of samples after LBTH pretreatment only presented a broad highly amorphous peak located at 20.8°, which is consistent with the previously reported maximum peak of typical amorphous cellulose regenerated by ILs. , According to the peak deconvolution method, the CrI values of HDP, the sample after LBTH pretreatment for 30 min (L30), and the samples after LBTH pretreatment for 60 min (L60) were 83.23, 48.70, and 36.56%, respectively (Figure f). Thus, after LBTH pretreatment, the crystalline structure of HDP was changed from cellulose Iβ to a highly amorphous structure, and the crystallinity of cellulose clearly decreased due to the de-crystallization and de-construction effect of LBTH on HDP.…”

“…48,49 As shown in Figure 6b, the crystalline structure of oxidized samples without LBTH pretreatment (such as HDP, the sample after NaIO 4 oxidized for 24 h, and the sample after NaIO 4 oxidized for 48 h) were cellulose Iβ (14.8, 16.5, and 22.6°). 36,37 However, after the LBTH pretreatment and oxidation process, the crystalline structure of LBTH-pretreated samples largely changed from cellulose Iβ (14.8, 16.5, and 22.6°) to amorphous structure (20.8°), and the crystallinity of cellulose clearly decreased due to the deconstruction and de-crystallinity effects of LBTH nondissolving pretreatment. 34 Furthermore, as shown in Figure 6c,d, the T o and T max of HDP after NaIO 4 oxidation for 48 h were 264.1 and 329.1 °C, respectively.…”

“…As shown in Figure 2e, the XRD patterns of cellulose samples without LBTH pretreatment showed typical peaks at 14.8, 16.5, and 22.6°, which were consistent with peaks of cellulose Iβ. 36,37 On the other hand, the XRD patterns of samples after LBTH pretreatment only presented a broad highly amorphous peak located at 20.8°, which is consistent with the previously reported maximum peak of typical amorphous cellulose regenerated by ILs. 34,38 According to the peak deconvolution method, the CrI values of HDP, the sample after LBTH pretreatment for 30 min (L30), and the samples after LBTH pretreatment for 60 min (L60) were 83.23, 48.70, and 36.56%, respectively (Figure 2f).…”

Biocomposites Films Based on Polylactic Acid and Olive Wood-Flour: Investigation on Physical, Thermal and Mechanical Properties

“…The Tg of PLA drops to 40.08°C for OW10, it is clear that OWF lowers the Tg because it makes the chains more mobile in the matrix due to their plasticization. 41 Due to its plasticizing effect, lignin can improve the fluidity of PLA chains, promotes crystal growth and increases crystallinity compared to neat PLA which increases from 29.22% to 43.42% for OW10 that is the higher crystallinity obtained (Table 3). Indeed, the crystallinity of the PLA matrix increases significantly as the OWF content increases, this may be due to the increase of cellulose in the biofilms, OWF could also act as nucleation agents to form a more ordered crystalline structure and PLA crystal.…”

“…The Tg of PLA drops to 40.08°C for OW10, it is clear that OWF lowers the Tg because it makes the chains more mobile in the matrix due to their plasticization. 41 Table 2. Films Thermal degradation temperatures (T5%, T10%, T25%) of the films at 5, 10 and 25 wt% mass losses and the maximum mass loss temperature (Tmax).…”