Papers by Author: Ahmed M. Al-Jumaily

Abstract: The introduction of plastic materials has revolutionised our society. However, excessive use of traditional, non-biodegradable plastic materials, especially for packaging applications, has created many environmental issues. During the past few decades, many biodegradable polymers, bio-based and petroleum-based, have been developed to address the above problem. Several research has been carried out on various biodegradable polymer blends and composites. However, their widespread application is still limited. This paper gives an overview and progress made on biodegradable polymers for flexible packaging applications, a critical analysis of their performance characteristics and recommendations on priority areas for further research. This Paper shows that, among the polyesters, though PHAs is most attractive concerning biodegradability, its low elongation at break, narrow processing temperature and high production cost limit their use for flexible packaging application. For flexible packaging applications, PBS (Polybutylene succinate) is better than PLA (Polylactic acid) and PHAs (Polyhydroxyalkonates), considering thermal characteristics and tensile elongation. In addition, PBS is biodegradable in compost, soil, lake and seawater, though its rate of biodegradation is reported to be slower compared to PHAs.

Abstract: Nowadays, developing highly biodegradable polymer films for flexible packaging applications is one of many researchers' demanding and challenging tasks. Conventional plastics/polymers are still being extensively used, creating environmental pollution. Because most of the commercially available plastic products are marketed as biodegradable are not truly biodegradable and have several limitations for making flexible packaging films. The main objective of this work is to manufacture biodegradable polymer blends, with the best performance characteristics, for flexible packaging applications. The paper focused on improving the properties, i.e., tensile, barrier, and biodegradation properties, of commercially available polymers such as Polybutylene succinate (PBS), Polyhydroxybutyrate (PHB), and Polylactic acid (PLA) by blending with Polycaprolactone (PCL) for flexible packaging application. Polymer films of various compositions such as PBS-PCL, PHB-PCL, and PLA-PCL blends were fabricated by injection molding and hot pressing. The characterization analysis included analyzing polymer blends' tensile and water vapor barrier properties, as per ASTM D882-18 method and ASTM E96-16 method, respectively, following that biodegradation analysis in compost (ASTM D5338-15 method) and seawater medium (ASTM D6991-17 method) of the polymer blends, and analysis of PCL blends' effect. The research showed that compared to the pure polymer blends such as PBS, PHB, and PLA blends, polymer blends with 20% of PCL has increased tensile elongation by 26.3%, 68%, and 171%, respectively, and the water vapor barrier properties were increased by 28.3%, 26.8%, and 30.3%. the biodegradation rate in compost medium was increased by 21.9%, 6.4% and 21.2%, and the biodegradation rate in seawater medium was increased by 31%, 7.5%, and 16.6%, respectively, even though a slight decrease in tensile strength. In conclusion, the polymer blends with 20wt% of PCL provide overall improved of polymer properties.

Abstract: Nowadays, biodegradable polymers such as Polybutylene succinate (PBS), Polyhydroxybutyrate (PHB), and Polylactic acid (PLA) are widely used commercially, especially in flexible packaging applications, but these polymers have certain limitations in their properties. The main aim of this study was to develop biodegradable polymer films with improved performance characteristics. This paper focused on developing and enhancing the characterization such as tensile properties, water barrier properties, and biodegradation properties of PBS-PCL(Polycaprolactone), PHB-PCL, and PLA-PCL blends, with the addition of 5wt% of plasticizer [GTA (Triacetin/ glycerol triacetate), a monomeric plasticizer P1, Ultramoll, a polymeric plasticizer P2; and mixed plasticizer P3 (1: 1 mix of P1 and P2)] for flexible packaging application. The plasticized polymer films (thickness 0.25mm) was prepared by injection molding and hot pressing method, and analyze the characterization such as tensile properties (ASTM D882-18 method), water vapor barrier properties (ASTM E96-16 method), and the biodegradation properties in compost (ASTM D5338-15 method), and seawater (ASTM D6991-17 method) medium, and analysis the effect of plasticizers on plasticized polymer blends. The research shows that compared to polymers blends such as PBS, PHB, and PLA, with 20wt% of PCL, there was a significant increase in tensile elongation by 22%,76.6%, and 139.3%, respectively and an increase in biodegradability by 19.5%, 3.6%, and 38.9% in compost medium, and 22.1%, 1.8%, and 41.0% in seawater medium, respectively, with the addition of all three 5wt% plasticizers (Ultramoll), though the tensile strength and water vapor properties were decreased. The plasticizer study shows that plasticized polymer blends using mixed plasticizer (P3) provide the best overall performance enhancement.

Abstract: Polymer nanocomposites based on carbon nanotubes attract a great deal of attention recently due to their excellent performance. The dispersion state of CNTs embedded in the matrix is the primary and key issue to realize the potential of the nanocomposite. Here, this paper considers how the boiling point of solvent affects the performance of the nanocomposite when the ultrasonication dispersion method is employed. It is found that solvent with a low boiling point is conducive to save evaporation time so that CNTs can maintain the homogenous dispersion state as much as possible after ultrasonication. Therefore, the stretchability and tensile strength can be improved, while the electrical conductivity has an obvious enhancement as well.

Abstract: The preliminary results of gel swelling experiments are reported, and then compared to predictions made by a recently-developed finite element model (FEM). This model utilises energy transport between different energy domains, and is being used to simulate gel swelling dynamics. Initial experiments have revealed the model does capture the general behaviour of polymer hydrogel swelling dynamics and further improvements are necessary for better accuracy.