In this article, the mechanical, morphological, and dynamic-mechanical properties of the blends of PLA and kenaf bast short fiber were investigated. The composites, with different fiber loading and triacetin content, were prepared by melt blending techniques using a Brabender internal mixer at 60 rpm and 170°C for 10 min and their properties were examined. Pure PLA was used as a reference for the biocomposite samples. Triacetin was used as a plasticizer for PLA and PLA/kenaf composites in order to study the improvement in tensile properties. The tensile strength and stiffness of unplasticized biocomposite materials decreased with the addition of kenaf bast fibers but improved with the addition of triacetin. The optimum fiber loading was 30 wt% kenaf fibers in the PLA matrix with the addition of 5% triacetin. The dynamic mechanical analyses showed that triacetin improved the thermal stability of the biocomposites. The triacetin increased the storage modulus and gave a lower softening temperature for plasticized biocomposites. The micrographs of the tensile specimens and their fractured surfaces, which were examined by scanning electron microscopy, demonstrated that better adhesion between the fibers and the matrix was achieved with the addition of the plasticizer.

The aim of this study is to determine the effect of alkali treatment on water absorption and tensile properties of non-woven kenaf polyester composite. Kenaf fiber mat was treated with 2, 4 and 6% of different sodium hydroxide (NaOH) concentration. The composite was fabricated using compression molding technique. It was found that treatment reduced the overall water uptake of composites. The 6% treated fibre composite was greater in moisture resistance as compared to untreated. The tensile strength of the composites was substantially improved after alkali treatment, and it was similar with the tensile modulus.

This study is focusing on the presence of pigments called anthocyanin in hibiscus, can be used as pH indicator as the pigments react with OH⁻ ions before changing its color depending on the acidity or alkalinity of the surroundings. Hence, a system for pH monitoring based on chitosan, corn starch and phytochemical extract from Hibiscus rosa-sinensis (hibiscus), all inexpensively obtained from renewable sources is developed. Chitosan, corn starch and hibiscus extract were used to produce biopolymer pH indicator for smart food packaging. The system is then characterized by using FT-IR, as well as light microscopy. In order to validate the use of this system as a meat spoilage detection sensor, application tests were conducted with chicken breasts. The results show that the system has good optical and morphological properties and is very sensitive to pH variations. During the application test, the s ystem visually indicated pH changes. This shows a clear response to pH variation of the samples. Therefore, it has potential to be used as a visual indicator of the storage and consumption conditions of food.

This study was conducted to improve the life-span of the biofilm produced from algae by evaluating the decomposition rate with the effect of cinnamon extraction oil (CEO). The biofilm was fabricated using the solution casting technique. The soil burying analysis demonstrated low moisture absorption of the biofilm, thus decelerating the degradation due to low swelling rate and micro-organism activity, prolonging the shelf-life of the biofilm. Hence, the addition of CEO also affects the strength properties of the biofilm. The maximum tensile strength was achieved with the addition of 5% CEO, which indicated a good intermolecular interaction between the biopolymer (algae) and cinnamon molecules. The tensile strength, which was measured at 4.80 MPa, correlated with the morphological structure. The latter was performed using SEM, where the surface showed the absence of a separating phase between the biofilm and cinnamon blend. This was evidenced by FTIR analysis, which confirmed the occurrence of no chemical reaction between the biofilm and CEO during processing. The prolongation shelf-life rate of biofilm with good tensile properties are achievable with the addition of 5% of CEO.

In this study, melt blended compositions of pure PLA with additions of polyethylene glycol (PEG) up to 30 wt% were prepared. Fourier-transform infrared spectroscopy (FTIR), differential scanning calorimeter (DSC), and thermogravimetric analysis (TGA) were used to investigate the properties of PLA/PEG blends, such as structural, thermal, and morphological properties. The results showed that further increments of PEG cause the -OH group of PLA/PEG blends to show a broad peak, indicating that there is hydrogen bonding interaction between PEG and PLA chains. DSC result revealed that the addition of PEG decreases the glass transition temperature from 57 °C to 46 °C and crystallization temperature from 107 °C to 87 °C. Such trends suggest enhanced chain mobility of PLA chains. TGA thermograms showed that further additions of PEG into PLA resulted in a consistent shift to lower temperature and decrease in thermal stability. Optical microscopy (OM) and scanning electron microscopy (SEM) observations of the melt spun PLA/PEG microfibers revealed that the diameter of the microfibers averaged between 15 to 80 microns. ABSTRAK: Kajian ini menganalisa komposisi adunan lebur PLA asli bersama tambahan polietilena glikol (PEG) sebanyak 30%. Penjelmaan Fourier spektroskopi inframerah (FTIR), kalorimeter pengimbasan pembezaan (DSC) dan analisis termogravimetri (TGA) telah digunakan bagi mengkaji sifat-sifat adunan PLA/PEG, seperti struktur, terma dan sifat-sifat morfologi. Keputusan menunjukkan penambahan PEG seterusnya menyebabkan kumpulan -OH campuran PLA/PEG memberikan puncak yang lebar, ini menunjukkan ada interaksi ikatan hidrogen antara rantaian PEG dan PLA. Keputusan DSC menunjukkan penambahan PEG mengurangkan perubahan gelas dari 57 °C kepada 46 °C dan suhu kristalisasi dari 107 °C kepada 87 °C. Trend ini mencadangkan peningkatan pergerakan rangkaian pada rantaian PLA. Termogram TGA menunjukkan dengan penambahan berterusan PEG ke dalam PLA menghasilkan penurunan konsisten pada suhu dan pengurangan kestabilan haba. Pemerhatian mikroskop optik (OM) dan mikroskopi elektron penskanan (SEM) mikrofiber spun lebur PLA/PEG menunjukkan purata diameter mikrofiber ini antara 15 ke 80 mikron.