No abstract

Packaging is an essential component in food industries. Packaging protects food from spoilage between processing and usage by the consumer. In this study, biocomposites of poly(lactic acid) (PLA) reinforced with durian skin fibre (DSF) were prepared by extrusion and compression moulding. Epoxidized palm oil (EPO) was added into PLA/DSF biocomposite as a plasticizer. The results showed that the thermal stability of PLA/DSF biocomposite with EPO has not much difference compared to without EPO. The degradation time of PLA/DSF biocomposite also faster after it was disposed to the landfill as it took around 65 days to degrade. Fourier transform infrared (FTIR) confirmed the stability of EPO where the oxirane group of EPO existed in the PLA/DSF biocomposite. Therefore, PLA/DSF biocomposite with addition of EPO can be effectively used for food packaging application.

Biopolymer products that is biodegradable presently attracting an attention from researchers and industry. The biodegradable packaging based on polylactic acid (PLA), durian skin fibre (DSF), epoxidized palm oil (EPO) and incorporated with cinnamon essential oil (CEO) as antimicrobial agent have been developed and showed to be a promising field of research. This paper reported the effects of supercritical carbon dioxide on the degradation and antimicrobial properties of PLA biocomposite films produced via solvent casting. The biocomposites underwent supercritical carbon dioxide (SCCO2) treatment at two different conditions under 40 °C temperature and at 100 bar and 200 bar pressure. Water absorption test showed that the untreated PLA biocomposite absorbed most water as compared to treated PLA biocomposite with SCCO2 at 5.1%. This is due to the hydrophilic nature of the fibre that absorbed water molecules. Soil burial test showed that the treated PLA biocomposite possessed the highest value of weight losses after 80 days with 97.8%. Biocomposite with the presence of CEO demonstrated antimicrobial activity against both gram-positive and gram-negative bacteria. This showed that SCCO2 significantly improved the properties of PLA biocomposite films. The supercritical fluid treatment of PLA biocomposite could be an alternative for active packaging industries to ensure that the packaging product meets the requirement by consumers as well as being an eco-friendly product. ABSTRAK: Produk biopolimer yang biodegradasi pada masa ini menarik perhatian dari penyelidik dan industri. Pembungkusan biodegradasi berasaskan polilaktik asid (PLA), serat kulit durian (DSF), minyak kelapa sawit terepoksi (EPO) dan ditambah dengan minyak pati kayu manis (CEO) sebagai agen antimikrobial telah dibangunkan dan menjadi bidang penyelidikan. Artikel ini melaporkan kesan karbon dioksida superkritikal terhadap sifat-sifat degradasi dan antimikrobik dari filem biokomposit PLA yang dihasilkan melalui pemutus pelarut. Biokomposit telah menjalani rawatan superkritikal karbon dioksida (SCCO2) pada dua keadaan yang berbeza di bawah suhu 40 °C pada 100 bar dan 200 tekanan bar. Ujian penyerapan air menunjukkan bahawa biocomposite PLA yang tidak dirawat menyerap kebanyakan air berbanding komposisi lain dengan 5.1%. Ini disebabkan sifat hidrofilik serat yang menyerap molekul air. Ujian penanaman dalam tanah menunjukkan bahawa biocomposite PLA yang dirawat mempunyai nilai kehilangan berat tertinggi setelah 80 hari dengan 97.8%. Biokomposit dengan kehadiran CEO menunjukkan aktiviti antimikrobial terhadap bakteria gram-positif dan gram-negatif. Ini menunjukkan bahawa SCCO2 meningkatkan sifat-sifat filem biocomposite PLA. Rawatan cecair superkritikal PLA biocomposite boleh menjadi alternatif bagi industri pembungkusan untuk memastikan produk pembungkusan memenuhi keperluan pengguna serta menjadi produk mesra alam.

The exploration of new biocomposites that are environmental friendly is gain attention due to depletion of petroleum resources and increasing global environmental concern. Therefore, the investigation of environmental friendly and sustainable materials requires to substitute the synthetic based materials. This project is conducted to investigate the effect of supercritical carbon dioxide on tensile properties of PLA/DSF biocomposite films. The PLA/DSF biocomposites are produced via solvent casting method. Then, the samples are treated under supercritical carbon dioxide (SCCO2) at 40 o C and at 200 bar pressure. From tensile properties, it was found that the tensile strength and modulus for untreated and treated PLA/DSF biocomposite are higher compared to net PLA which are 24.9 MPa and 23.5 MPa. Thus, the addition of durian skin fiber improved the mechanical strength PLA polymer. But, the presence of foams and pore in treated PLA/DSF biocomposites decreased its tensile properties by 1.4 MPa less compared to untreated samples as confirmed by morphological observations under scanning electron microscope.

Durian skin fibre (DSF) reinforced high-density polyethylene (HDPE) composite was fabricated by melt-blending and then compression moulded. As DSF is polar and hydrophilic in nature, while HDPE is non-polar and hydrophobic, thus the adhesion between them is low. Therefore, maleic anhydride-grafted-polyethylene (MAPE) was added to enhance the interaction of HDPE and DSF. This paper highlight the effect of MAPE on UV degradation exposure on HDPE/DSF composite. DSF content from 10, 20, 30 and 40 wt% were immersed in water for 70 days. In the absence of MAPE, water absorption increased with DSF loadings. Furthermore, tensile properties of HDPE/DSF composite was degraded after 500, 1000 and 2000 h of UV radiation exposure. Morphological observation under SEM showed that the fibre and matrix became less interacted after exposed to UV radiation. Voids and gaps between HDPE and DSF in the presence of MAPE were reduced as revealed under SEM micrographs. The colour index of the HDPE/DSF composite was increased and became whiter with UV radiation exposure. This showed that MAPE significantly improved the interaction of HDPE/DSF composite.