Preparation of Transparent Fast-Growing Poplar Veneers with a Superior Optical Performance, Excellent Mechanical Properties, and Thermal Insulation by Acetylation Modification Using a Green Catalyst

Abstract

There has been growing interest in transparent conductive substrates due to the prevailing flexible electron devices and the need for sustainable resources. In this study, we demonstrated a transparent fast-growing poplar veneers prepared by acetylated modification, followed by the infiltration of epoxy resin. The work mainly focused on the effect of acetylation treatment using a green catalyst of 4-Dimethylpyridine on the interface of the bulk fast-growing poplar veneer, and the result indicated that the interface hydrophobicity was greatly enhanced due to the higher substitute of acetyl groups; therefore, the interface compatibility between the cell wall and epoxy resin was improved. The obtained transparent fast-growing poplar veneers, hereafter referred to as TADPV, displayed a superior optical performance and flexibility, in which the light transmittance and haze were 90% and 70% at a wavelength of 550 nm, respectively, and the bending radius and bending angle parallel to grain of TADPV were 2 mm and 130°, respectively. Moreover, the tensile strength and tensile modulus of the TADPV were around 102 MPa and 198 MPa, respectively, which is significantly better than those of the plastic substrates used in flexible electron devices. At the same time, the thermal conductivity tests indicated that TADPV has a low coefficient of thermal conductivity of 0.34 Wm−1 K−1, which can completely meet the needs of transparent conductive substrates. Therefore, the obtained TADPV can be used as a candidate for a flexible transparent substrate of electron devices.

One-pot cellulose etherification and self-crosslinking via a mild hydroxyl–yne click reaction in a homogeneous system

“…[1][2][3][4] Cellulose-based materials are considered one of the best biobased alternatives to fossil-based plastic polymers due to their sustainability, biocompatibility, excellent mechanical properties, and low price. 7,8 However, due to the lack of UV-shielding moieties, cellulose-based materials show inferior anti-ultraviolet aging ability, which limits their practical applications. 9,10 In this regard, chemical modification of cellulose towards achieving excellent UV-blocking properties is an appealing way to broaden the utilization of cellulose.…”

Acetylation of Nanocellulose: Miscibility and Reinforcement Mechanisms in Polymer Nanocomposites

“…There are numerous reports on improvement of mechanical properties of nanocomposites based on acetylated nanocellulose . It is not unusual to make the statement that improved properties are a result of improved compatibility between the cellulosic reinforcement and the polymer matrix, , often based on the intuitive perception that acetylation leads to hydrophobization. This view is supported by the significantly reduced hygroscopicity of acetylated cellulosic fibers. ,, However, using the term compatibility in this nonspecific manner is imprecise, as it simply reflects a general improvement of properties when components are mixed, while the actual mechanisms remain speculative.…”