Agar-Based Composite Films as Effective Biodegradable Sound Absorbers

Abstract

We investigated the use of seaweed-derived agar-based composite films as sound absorbers. Nonporous and porous films of varying concentrations of agar (1% to 5% w/v) and their composite films with glycerol (5% w/w) as the plasticizer and nanocrystalline cellulose (2% to 10% w/w) as the reinforcement material were fabricated. Porous films, of about 80% porosity, were obtained by a freeze-drying technique and nonporous films by drying in a hot air oven. Scanning electron microscopy study showed that porous films had interconnected walls with a pore size of 10 μm. Measured acoustic absorption coefficients using the twomicrophone transfer function method revealed that the porous films were effective in sound absorption. The films of 5% w/v agar concentration had the highest sound absorption. The addition of glycerol enhanced sound absorption, due to the damping nature induced by it, whereas the addition of nanocrystalline cellulose to the glycerol-added films did not alter its acoustic properties.

Burst and Physicochemical Characteristics of Glycerol-Added Chitosan Films for Food Packaging

“…The morphologies of all films were examined using a field emission scanning electron microscope (FESEM) (ΣIGMA, Carl Zeiss, Germany). 9 Since the films were nonconducting, Pt−Au coating was done using a sputtering unit (SC7620 mini sputter coater, UK). Imaging was performed at 5 kV and energy dispersive spectroscopy (EDS) was performed at 20 kV.…”

“…Toward fitting in the United Nations 17-point agenda for sustainable development, , efforts have increased to develop alternative synthetic packaging materials from biological sources such as agricultural waste , and animals. Fossil fuel-based biodegradable polymers are polybutylene adipate terephthalate (PBAT), polybutylene succinate (PBS), and polyhydroxyalkanoate (PHA).…”

Binder‐free, non‐carcinogenic surfactant‐based cellulose‐rich bagasse foams as acoustic panels

“…The acoustic absorption coefficient and transmission loss (TL) of bagasse board and foams were measured in an acoustic impedance tube built 11 according to ASTM standards 53,54 . The measurements of and TL required different configurations.…”

“…Toward sustainable development, the United Nations 10 in the year 2015 emphasized recyclability and biodegradability for all materials; these include sound‐absorbing materials. Hence, efforts focused on developing biodegradable materials from abundant natural materials available in abundance 11,12 using green fabrication methods. The materials explored can be classified into three types: (i) naturally available fibrous agricultural residue 13,14 ; (ii) engineered materials comprising recycled paper and other scrap materials, such as wool and nonwoven polyester fabric have been explored 15 ; and (iii) a combination of thermosetting polymers and biomaterials 16 .…”

Mechanically flexible and flame-retardant cellulose nanofibril-based films integrated with MXene and chitosan

“…Polymer materials based on natural biopolymers (e.g., starch, alginate, and so on) [1][2][3][4] that integrate mechanical flexibility, biodegradability and inexpensiveness are of great importance for achieving the goals of carbon neutrality and sustainable development. Cellulose nanofibrils (CNFs), as bio-based nanomaterials with a filamentous morphology [5] and tunable surface charge characteristics [6] , have attracted tremendous research interest due to their abundant reserves and excellent overall performance [7,8] .…”