Transparent Composites Made from Tunicate Cellulose Membranes and Environmentally Friendly Polyester

Abstract

A series of optically transparent composites were made by using tunicate cellulose membranes, in which the naturally organized cellulose microfibrillar network structure of tunicate tunics was preserved and used as the template and a solution of glycerol and citric acid at different molar ratios was used as the matrix. Polymerization through ester bond formation occurred at elevated temperatures without any catalyst, and water was released as the only byproduct. The obtained composites had a uniform and dense structure. Thus, the produced glycerol citrate polyester improved the transparency of the tunicate cellulose membrane while the cellulose membrane provided rigidity and strength to the prepared composite. The interaction between cellulose and polyester afforded the composites high thermal stability. Additionally, the composites were optically transparent and their shape, strength, and flexibility were adjustable by varying the formulation and reaction conditions. These composites of cellulose, glycerol, and citric acid are renewable and biocompatible and have many potential applications as structural materials in packaging, flexible displays, and solar cells.

Large‐Size Transparent Wood for Energy‐Saving Building Applications

“…However,t he intrinsic properties of wood, including low corrosion resistance, poor mechanical performance, flammability,n on-transparency, and non-thermal conductivity,have limited its applicationsinthe building indus-try. [12,13] The modified wood has been extensively utilized in energysaving window applications owing to its comparable optical transmittance, good thermal insulation, and favorable mechanical performance in comparison with the traditional glass. [7][8][9][10] To address the issue of energy shortage, it is highly desired to reduce the energy consumption of residential and commercial buildings, because they account for over 50 %o ft he total energy consumption.…”

“…[11] Recently,d ifferent types of cellulose from various sourcesw eret ested to prepare transparent materials, such as bacterial or tunicate. [12,13] The modified wood has been extensively utilized in energysaving window applications owing to its comparable optical transmittance, good thermal insulation, and favorable mechanical performance in comparison with the traditional glass. [14] The transparent wood was mainly fabricated by removing light-absorbing substancesa nd introducing ar efractive indexmatching polymer.…”

Esterification of citric acid with locust bean gum

“…In this mechanism, The citric acid carbonyl group was protonated and reacts the hydroxyl (OH) group at C-6 atoms of mannose and galactose, produces tetrahedral cation. Oxygen in OH was protonated ( + OH 2 ) to convert the OH loose, H 2 O loss and produce the ester (CA-LBG) [17, 18]. Based on the spectra of Fourier transform infrared (Fig.…”

The comparison of the properties of nanocellulose isolated from colonial and solitary marine tunicates

“…The tunicate cellulose is highly crystalline (85-100%) and contains I β crystal structure [10]. The quality of tunicate cellulose is superior to plant-based cellulose in terms of molecular weight, mechanical properties, water holding capacity, permeability, and thermal stability [11]. Besides, the crystallinity index (CI) of tunicate cellulose is comparable to the CI of algal cellulose and higher than plant-based cellulose and bacterial cellulose [5].…”