Preparation and Characterisation of Cellulose-Shellac Biocomposites

Abstract

Composite materials comprising a mixture of shellac resin as the matrix and cellulose as the reinforcement were developed. The influence of the reinforcement content and the concentration of additives on the mechanical performance and processing were investigated. A high content of cellulose and low concentrations of ethanol and polyethylene glycol produced biocomposites with high stress resistance and a high Young's modulus, whereas a low content of cellulose and a high concentration of additives gave samples a low Young's modulus and high elasticity. Two types of cellulose-based reinforcements with different polarity, namely, mechanically refined wood pulp and cellulose acetate butyrate particles, were compared. The efficiency of the composite over the two model reinforcements, i.e., hydrophilic and hydrophobic components, respectively, was also studied. Although particle reinforcement was easier to process and evenly dispersed into the matrix, its mechanical performance was lower compared with refined fibres. Scanning electron microscopy showed that the matrix better coated the fibres than the particles, resulting in better adhesion and mechanical performance. The morphology of reinforcement played a key role; long fibres oriented in the pulling direction ensured a better mechanical resistance than particle fillers.

Topochemical Engineering of Cellulose-Based Functional Materials

“…On the basis of the characterization of cellulose–shellac composites, they can be classified from hard material ( E = 1731 ± 300 MPa) to soft ( E = 0.40 ± 10 MPa). 55 These composite materials will potentially find a place in reinforced fiber applications such as building components, packaging, and fabrics. The disadvantage associated with this material is that it cannot be used in applications where the temperature is above 80 °C as shellac might start to melt if it is used in its dewaxed form.…”

“…PEG acted as a plasticizer and improved the interfacial interaction between cellulose and shellac by its C–O–C- and O–H-initiated dipolar interaction and hydrogen bonding. On the basis of the characterization of cellulose–shellac composites, they can be classified from hard material ( E = 1731 ± 300 MPa) to soft ( E = 0.40 ± 10 MPa) . These composite materials will potentially find a place in reinforced fiber applications such as building components, packaging, and fabrics.…”

Sicilian Byzantine Icons through the Use of Non-Invasive Imaging Techniques and Optical Spectroscopy: The Case of the Madonna dell’Elemosina

“…The similarities found between the FT-IR spectra (in the stretching zone of the C-H (3000-2800 cm −1 and below 1800 cm −1 , Figure S11)) allow us to state that the nature of the analyzed surface is similar in all the analyzed areas, which is in agreement with what was observed under UV light. Alcoholic groups with a large peak centered at 3400 cm −1 (stretching -OH aliphatic), C-H stretching at 2926 and 2859 cm −1 and at 1726 cm −1 (aldehyde/aliphatic ketone C-O-C, carboxylic acid stretching), and ester, acid, and alcoholic groups at 1250, 1165, and 1060 cm −1 , respectively, are present [35], ascribable to the shellac resin. Furthermore, the presence of the double peak at 730 and 720 cm −1 is ascribable to a partially crystalline hydrocarbon chain, Ref.…”

Penggunaan Sekresi Kutu Lak pada Pembuatan Biokomposit dari Sabut Kelapa

“…Struktur kimia kutu lak sangatlah komplek dan utamanya terdiri dari berbagai asam, asam aleuritis dan asam jalaris (Obradovic et al, 2017) sebagai mana ditunjukkan di Gambar 2. Menurut Reshma et al, (2018) kutu lak terdiri dari resin berjumlah 68 sampai 90%, dye berjumlah 2 sampai 10%, malam berjumlah 5 sampai 6%, bahan-bahan mineral berjumlah 3 sampai 7% bahan albuminous berjumlah 5 sampai 10%, dan air berjumlah 2 sampai 3%.…”