Synthesis and characterization of polylactic acid (pla)/inear low-density polyethylene (lldpe) nanocomposites / Waleed Ali Murshed Hasan Alhadadi
Waleed Ali Murshed Hasan Alhadadi,
Synthesis and characterization of polylactic acid (pla)/inear low-density polyethylene (lldpe) nanocomposites / Waleed Ali Murshed Hasan Alhadadi - xii, 153 pages : illustrations 30 cm. + 1 CD-ROM
College of Engineering
Thesis (Master of Science) -- Universiti Malaysia Pahang – 2022
Includes bibliographical references
Bioplastic derived from renewable biomass and an eco-friendly material; poly(lactic) acid (PLA) has high potential in substituting petrochemical based plastics. However, despite the good strength, the weakness such as poor toughness making it not ready for the application in industry. Nevertheless, the properties of PLA can be toughened by adding other polymers such as linear low-density polyethylene (LLDPE) which is tough, durable and strong. The binary blend of PLA/LLDPE can result in an immiscible blend with low strength. In order to enhance the chemical interactions in the binary blend by using PE-g-MA as compatibilizer (revise sentence). Graphene nanoplatelet could be incorporated in the compatibilized binary blend of PLA/LLDPE to increase the mechanical strength and thermal stability. The goal of this study was to prepare and characterize poly(lactic) acid (PLA)/linear low-density polyethylene (LLDPE)/graphene nanoplatelets (GNP) nanocomposites. The samples were prepared using a twin-screw extruder with the temperature between 150 and 190 ºC and 60 rpm of screw speed. The nanocomposites blends were characterized based on morphological, mechanical, thermal and chemical properties. The findings provided that the optimum ratio of PLA/LLDPE binary blend was at 10% wt of LLDPE (PLA90/LLDPE10) with elongation at break enhanced by 23%. The tensile strength, elongation at break and Young’s modulus were observed to increase with the addition of 3 phr of PE-g-MA compatibilizer into PLA90/LLDPE10 blend by 5, 3 and 2.3%, respectively. It was observed that the morphological images by SEM show the presence of PE-g-MA compatibilizer contributed to the reduction of voids size in the blend. The nanocomposites were prepared using GNP with two different average particle diameters (5 microns (GNP M5) and 25 microns (GNP M25)) at 3 phr. It was found that the optimum ratio of PLA/LLDPE/PE-g-MA was 3 phr of GNP M5. The elongation at break and tensile strength improved by 40% and 4%, respectively in relative to the pristine PLA. On the other hand, it was noted that the GNP M25 decreased in relative to tensile strength by 6% and increased the elongation at the break by 84% as compared to pristine PLA. Morphological analysis from FESEM images revealed that the compatibilized binary blend with GNP M25 displays better uniformity and more homogenous morphology compared to GNP M5. The better uniformity of nanocomposites indicates a remarkable degree of dispersion of the GNP, which contributed to the increase in thermal and mechanical properties. The presence of GNP contributed to the slight improvement of degradation temperatures especially at higher loadings of GNP in the compatibilized binary blend systems. From the FTIR and Raman results, it can be suggested that no chemical interaction existed with polymer matrices when GNP nanofiller was added. This study shown that the brittle PLA can be toughened by LLDPE, compatibilized with PE-g-MA and reinforced by GNP.
THE0009534 (Local)
College of Engineering--Dissertations
Universities and colleges--Dissertations
Theses--Dissertations
Synthesis and characterization of polylactic acid (pla)/inear low-density polyethylene (lldpe) nanocomposites / Waleed Ali Murshed Hasan Alhadadi - xii, 153 pages : illustrations 30 cm. + 1 CD-ROM
College of Engineering
Thesis (Master of Science) -- Universiti Malaysia Pahang – 2022
Includes bibliographical references
Bioplastic derived from renewable biomass and an eco-friendly material; poly(lactic) acid (PLA) has high potential in substituting petrochemical based plastics. However, despite the good strength, the weakness such as poor toughness making it not ready for the application in industry. Nevertheless, the properties of PLA can be toughened by adding other polymers such as linear low-density polyethylene (LLDPE) which is tough, durable and strong. The binary blend of PLA/LLDPE can result in an immiscible blend with low strength. In order to enhance the chemical interactions in the binary blend by using PE-g-MA as compatibilizer (revise sentence). Graphene nanoplatelet could be incorporated in the compatibilized binary blend of PLA/LLDPE to increase the mechanical strength and thermal stability. The goal of this study was to prepare and characterize poly(lactic) acid (PLA)/linear low-density polyethylene (LLDPE)/graphene nanoplatelets (GNP) nanocomposites. The samples were prepared using a twin-screw extruder with the temperature between 150 and 190 ºC and 60 rpm of screw speed. The nanocomposites blends were characterized based on morphological, mechanical, thermal and chemical properties. The findings provided that the optimum ratio of PLA/LLDPE binary blend was at 10% wt of LLDPE (PLA90/LLDPE10) with elongation at break enhanced by 23%. The tensile strength, elongation at break and Young’s modulus were observed to increase with the addition of 3 phr of PE-g-MA compatibilizer into PLA90/LLDPE10 blend by 5, 3 and 2.3%, respectively. It was observed that the morphological images by SEM show the presence of PE-g-MA compatibilizer contributed to the reduction of voids size in the blend. The nanocomposites were prepared using GNP with two different average particle diameters (5 microns (GNP M5) and 25 microns (GNP M25)) at 3 phr. It was found that the optimum ratio of PLA/LLDPE/PE-g-MA was 3 phr of GNP M5. The elongation at break and tensile strength improved by 40% and 4%, respectively in relative to the pristine PLA. On the other hand, it was noted that the GNP M25 decreased in relative to tensile strength by 6% and increased the elongation at the break by 84% as compared to pristine PLA. Morphological analysis from FESEM images revealed that the compatibilized binary blend with GNP M25 displays better uniformity and more homogenous morphology compared to GNP M5. The better uniformity of nanocomposites indicates a remarkable degree of dispersion of the GNP, which contributed to the increase in thermal and mechanical properties. The presence of GNP contributed to the slight improvement of degradation temperatures especially at higher loadings of GNP in the compatibilized binary blend systems. From the FTIR and Raman results, it can be suggested that no chemical interaction existed with polymer matrices when GNP nanofiller was added. This study shown that the brittle PLA can be toughened by LLDPE, compatibilized with PE-g-MA and reinforced by GNP.
THE0009534 (Local)
College of Engineering--Dissertations
Universities and colleges--Dissertations
Theses--Dissertations