Thermoplastic agar/chitosan blend was prepared by a rheomix process, and the effect of concentration agar: chitosan on the material properties forms were investigated. This research aimed to observe the physical properties of bioplastic agar/chitosan produced through rheomix. Bioplastic was produced by mixing 65 % solid material (agar: chitosan) and 35% glycerol, the ration through the melting process at an initial temperature of 100°C. The weight ratio of agar : chitosan was 65% : 0% (F0/control), 52% : 13% (F1), 39 % : 26% (F2), 26 %: 39% (F3). The tensile strength and elongation of bioplastic were decrees with a higher chitosan concentration. The color and the opacity of bioplastic were affected by the ratio of agar: chitosan. The moisture content and the water vapor transmission rate (WVTR) of bioplastic were increased by increasing the chitosan ratio. The SEM micrograph of bioplastic showed that the blend agar and chitosan seem to have a rough and inhomogeneous surface than pure bioplastic agar. The best blend was bioplastic with agar: chitosan 52%: 13% (F1), which have properties of : tensile strength 4.95 ± 0.56 MPa, elongation at break 34.94 ± 0.99 %, moisture content 15.33 ± 0.43%, WVTR 3259.39 ± 28.12 g/m2.24 h.

Starch–carboxymethyl cellulose (CMC) bioplastics have limited mechanical properties. Carrageenan from seaweed is a potential reinforcement material for improving the mechanical properties of bioplastics. This study aimed to determine the effect of Kappa (κ)-carrageenan on the mechanical and thermal properties and biodegradability of starch–CMC bioplastics. In this study, carrageenan at concentrations of 0%, 10%, 15%, 20%, 25% and 30% was used. The melt-mixing process was conducted at 130 °C for 4 min, using a mixer and then hot-pressing (30 kgf/cm2) at 150 °C for 5 min. The results indicated that the higher κ-carrageenan concentration increased the strength of bioplastics up to 15.7 MPa. The fracture analysis via scanning electron microscopy–energy-dispersive X-ray spectroscopy indicated the distribution of sulfur (S) elements that described the dispersion of κ-carrageenan. The Fourier transform infrared spectroscopy spectra revealed that the interaction between the starch–CMC matrix and κ-carrageenan formed a tight hydrogen bond network. The lowest mass reduction observed by thermogravimetric analysis occurred in bioplastics with 25% carrageenan, decreasing by 48% compared with bioplastics without κ-carrageenan. The addition of κ-carrageenan was identified as not affecting the biodegradability of the bioplastics.

THE PHYSICOCHEMICAL CHARACTERISTICS OF RECYCLED-PLASTIC PELLETS OBTAINED FROM DISPOSABLE FACE MASK WASTES. The government policy to wear a face mask during the COVID-19 pandemic has increased disposable face mask wastes. Thus, to reduce such wastes, it is necessary to evaluate the physicochemical characteristics of disposable face masks wastes before the recycling process and the recycled products. In this study, physicochemical characterization of the 3-ply disposable face masks and the recycled plastic pellets after disinfection using 0.5% v/v sodium hypochlorite were evaluated. A set of parameters including the characterization of surface morphology by a scanning electron microscope (SEM), functional groups properties by a fourier transform infra-red spectroscopy (FT-IR), thermal behavior by a differential scanning calorimetry (DSC), tensile strength and elongation at break were evaluated. The surface morphological of each layer 3-ply disposable face mask showed that the layers were composed of non-woven fibers. The FT-IR evaluation revealed that 3-ply disposable face mask was made from a polypropylene. At the same time, the DSC analysis found that the polypropylene was in the form of homopolymer. The SEM analysis showed that the recycled plastic pellets showed a rough and uneven surface. The FT-IR, tensile strength and elongation at break of the recycled plastic pellets showed similarity with a virgin PP type CP442XP and a recycled PP from secondary recycling PP (COPLAST COMPANY). In summary, recycling 3-ply disposable face mask wastes to become plastic pellets is recommended for handling disposable face mask wastes problem.

SYNTHESIS L-LACTIC ACID FROM FERMENTATION OF CASSAVA PULP BY USING TEMPEH INOCULUM. This study used cassava waste pulp as a fermentation substrate to produce lactic acid using a tempeh inoculum. Tempeh inoculum is a mixed culture of Rhizopus with Rhizopus oligosporus as the primary fungus. Lactic acid is an organic acid most widely used in the food, pharmaceutical, cosmetic and chemical industries. One of the important uses of lactic acid is as a raw material for producing Polylactic Acid (PLA) biopolymers, namely polymers that can decompose naturally in a relatively fast time. The analysis was performed using the Response Surface Methodology (RSM) method and the Box Behnken Design (BBD) experimental design with substrate concentration parameters, inoculum concentration, and incubation time on lactic acid. The fermentation process is carried out using a flask shaker at a temperature of 30 ºC, pH 6.0, and a rotational speed of 150 rpm. The optimum yield for lactic acid is 6.65 g/L. It was acquired at substrate 20 g/L, inoculum concentration 0.30 % (w/v) at an incubation time of 72 hours.

Microcrystalline cellulose (MCC) is pure cellulose isolated from alpha cellulose. The demand for renewable and sustainable raw materials for the industry has developed as one of the most pressing challenges in recent decades. The seaweed processing industry produces a large amount of solid fibrous waste, which can be utilized as an additional source of cellulose feedstock. The increase in seaweed production continues to increase, as well as waste that can be used as another source of cellulose raw materials. This study used red seaweed i.e., Gracilaria verucosa and Echeuma cottonii to produce high-quality MCC. Gracilaria verucosa and Echeuma cottonii are treated chemically through alkali, bleaching, and acid hydrolysis to obtain pure MCC. Following the X-ray diffraction (XRD) analysis result, MCC in the standard had a crystallinity of 67.2%, while the Gracilaria verucosa-MCC (GV-MCC) sample was 53.0% and Echeuma cottonii-MCC (EC-MCC) was 58.4%. Fourier transform infrared (FTIR) spectroscopy showed that GV-MCC and EC-MCC almost resemble the MCC standard. The morphology characteristic from Scanning electron microscope (SEM) analysis presented the difference between raw material before and after isolation into MCC. According to the Particle size analyzer (PSA) result, the mean sizes of EC-MCC and GV-MCC are 0.786 and 0.522 µm, respectively. The isolation of MCC from red seaweed has the potential to be used in a wide range of industries.