Mechanical, thermal and morphological properties of poly(lactic acid)/ sugarcane bagasse fiber composites

• Main Author: Khoo, Rong Ze
• Format: Thesis
• Language: English
• Published: 2014
• Subjects: TN263-271 Mineral deposits. Metallic ore deposits. Prospecting; TN275-325 Practical mining operations. Safety measures
• Online Access: http://eprints.usm.my/32960/1/Msc_%28Mix_mode%29_Thesis_Khoo_Rong_Ze_MECHANICAL%2C_THERMAL_AND__2014_MSc_M%26ME_BSB_24.pdf; http://eprints.usm.my/32960/

Komposit poli(asid laktik)/gentian hampas tebu (PLA/SCBF) disediakan dengan menggunakan kaedah penyebatian leburan dan diikuti oleh pengacuanan mampatan. Minyak kacang soya terepoksida (ESO) dipilih sebagai pemplastik bagi komposit PLA/SCBF. Demi mengkaji kesan saiz gentian terhadap sifat-sifat komposit PLA, SCBF yang dirawat alkali (~5 mm) telah dihancurkan ke dalam bentuk serbuk dan dinamakan SCBFP (~500 μm). Sehubungan dengan itu, tiga parameter telah diselidik dalam kajian ini, iaitu kandungan SCBF (5-15 wt%), muatan ESO (5-15 phr) dan kesan SCBFP. Ujian hentaman Charpy digunakan untuk mengkaji kesan hentaman terhadap komposit PLA sementara sifat morfologi dikaji dengan menggunakan mikroskop electron penskanan pancaran medan (FESEM). Sifat terma komposit diperiksa dengan penganalisa mekanik dinamik (DMA), kalorimeter pengimbasan pembezaan (DSC) dan penganalisis thermogravimetrik (TGA). Kekuatan hentaman PLA telah dikurangkan dengan penambahan SCBF. Walau bagaimanapun, kekuatan hentaman komposit PLA/SCBF-10 telah ditingkatkan dengan kehadiran ESO disebabkan kesan pemplastikan. Poly(lactic acid)/sugarcane bagasse fiber (PLA/SCBF) composites were prepared using melt compounding followed by compression molding. Epoxidized soybean oil (ESO) was selected as plasticizer for the PLA/SCBF composites. In order to study the effect of fiber size on the properties of PLA composites, alkali treated SCBF (5 mm length) was grounded into powder form and designated as SCBFP (~500 μm). Accordingly, three parameters were investigated in this research, i.e., SCBF content (5-15 wt%), ESO loading (5-15 phr) and SCBFP effects. Impact properties of PLA composites were characterized by Charpy impact test while morphological properties were studied using field emission scanning electron microscopy (FESEM). Thermal properties of the composites were examined with dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC) and thermogravimetry analysis (TGA). The impact strength of PLA was reduced by the addition of SCBF.Nevertheless, the impact strength of PLA/SCBF-10 composites was improved significantly in the presence of ESO due to the plasticization effect. DMA results showed that the addition of SCBF increased the storage modulus (E’) of PLA, and the effect is more pronounced for the one containing SCBFP.