Effects of different interfacial modifiers on the properties of digital printing waste paper fiber/nanocrystalline cellulose/poly(lactic acid) composites

Abstract

Digital printing waste paper fiber/nano-crystalline cellulose/poly (lactic acid) (DPF/NCC/PLA) composites, modified through γ-methacryloxy propyl trimethoxy silane (KH570), isopropyl tri (dioctylpyrophosphate) titanate (TMC201), sodium hydroxide (NaOH), polyethylene glycol 6000 (PEG6000), and a composite silane coupling agent (KH570/PEG6000), were fabricated by melt blending and injection molding and the effects of different modifiers on the properties of composites were studied. Results showed that mechanical properties of the modified composites generally improved, and the best mechanical properties, including flexural, tensile and impact strength, were achieved PEG6000, KH570/PEG6000, and KH570 modification, respectively. Thermal performance analysis showed improved thermal properties of composites treated by KH570, but the crystallinity of the modified materials was increased. Both water absorption and degradation properties showed a decreasing trend, and water absorption performance was obviously improved after KH570/PEG6000 modification. Under the action of several modifiers, the diffusion coefficient, thermodynamic solubility and permeability of composites were reduced to varying degrees. Furthermore, scanning electron microscopy (SEM) demonstrated that interfacial adhesion and composite compatibility were improved with significantly fewer and smaller pores, as well as a fuzzy boundary among the three phases.

Waste Paper as a Valuable Resource: An Overview of Recent Trends in the Polymeric Composites Field

“…According to the authors, the interfacial adhesion must be improved to produce higher mechanical properties in the composites, which were tested in more recent work. The influence of different coupling agents, such as γ-methacryloxypropyltrimethoxy silane (KH570), isopropyl tri(dioctylpyrophosphate) titanate, sodium hydroxide, poly-ethylene glycol 6000 (PEG6000), and a composite silane (KH570/PEG6000) was evaluated for PLA/NCC/WP composites [ 79 ]. From the microscopy images, it was possible to conclude that all the coupling agents provided interfacial interaction between the polymer and the fillers, enhancing the material’s properties by different degrees depending on the modifier.…”

Advances in Bio-Based and Biodegradable Polymeric Composites

“…These functional groups can be either hydrophilic or hydrophobic. Lyuleeva et al [181] proposed that hydrophilic methacrylic acid (MAA) and hydrophobic tert-butyl acid (t-BMA) functional groups can be grafted onto a moisture-responsive material, as a way of tuning the humidity-sensing performance of the materials.…”

Modification of Cellulose Micro- and Nanomaterials to Improve Properties of Aliphatic Polyesters/Cellulose Composites: A Review

“…A similar effect was recently observed for composites produced by compression molding and based on PCL containing CNF modified by APTES: cellulose modification had virtually no effect on tensile strength and elongation at break, and only a slight improvement was found for Young’s modulus [ 175 ]. Virtually no improvement in mechanical properties was observed in the work of Zhang et al who prepared composites by hot molding from PLA, digital printing waste paper fibers (DPF), and CNC modified with APTES [ 181 ]. Most likely, such a dramatic difference in the properties of composites fabricated with the use of silanized cellulose micro- and nanomaterials is strongly related not only to the properties of different silanes, but also to the effectiveness of the cellulose modification, which, unfortunately, is not given sufficient attention in the recent studies.…”