Mohd Sapuan Salit

Materials selection and design

Material selection and design are integrated terms in the development of any product with a competitive cost. It is difficult to select appropriate material for any product design without having the knowledge on the importance of material selection in design. This chapter thus gives an overview on the new product development activities and some basic features of materials selection. Several new case concepts on the development of product are also introduced.

Preparation, Characterization and Thermal Degradation of Polyimide (4-APS/BTDA)/SiO2 Composite Films

Polyimide/SiO2 composite films were prepared from tetraethoxysilane (TEOS) and poly(amic acid) (PAA) based on aromatic diamine (4-aminophenyl sulfone) (4-APS) and aromatic dianhydride (3,3,4,4-benzophenonetetracarboxylic dianhydride) (BTDA) via a sol-gel process in N-methyl-2-pyrrolidinone (NMP). The prepared polyimide/SiO2 composite films were characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM) and thermogravimetric analysis (TGA). The FTIR results confirmed the synthesis of polyimide (4-APS/BTDA) and the formation of SiO2 particles in the polyimide matrix. Meanwhile, the SEM images showed that the SiO2 particles were well dispersed in the polyimide matrix. Thermal stability and kinetic parameters of the degradation processes for the prepared polyimide/SiO2 composite films were investigated using TGA in N2 atmosphere. The activation energy of the solid-state process was calculated using Flynn–Wall–Ozawa’s method without the knowledge of the reaction mechanism. The results indicated that thermal stability and the values of the calculated activation energies increased with the increase of the TEOS loading and the activation energy also varied with the percentage of weight loss for all compositions.

Manufacturing of Natural Fibre Reinforced Polymer Composites

In this chapter, a study of design for manufacturing of natural fi bre composites is presented. Initially, the link between design for manufacturing and manufacturing itself is discussed in the context of natural fi bre composites. An account of the manufacturing processes to produce products from natural fi bre composites is given. Various activities of design for manufacturing of natural fi bre composites in various industries are reviewed. Design for sustainability, a recent topic within design for manufacturing or concurrent engineering, in relation to natural fi bre composites is discussed and reviewed. Current work on development of packaging materials from sugar palm fi bre reinforced biopolymer composites encompassing materials selection of biopolymers and some testing is discussed. Finally, a case study on the application of design for sustainability guides for a natural fi bre composite product is presented.

Comparison of In Situ Polymerization and Solution-Dispersion Techniques in the Preparation of Polyimide/Montmorillonite (MMT) Nanocomposites

In this paper, Polyimide/Montmorillonite Nanocomposites (PI/MMT NCs), based on aromatic diamine (4-Aminophenyl sulfone) (APS) and aromatic dianhydride (3,3′,4,4′-benzophenonetetracarboxylic dianhydride) (BTDA) were prepared using in situ polymerization and solution-dispersion techniques. The prepared PI/MMT NCs films were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM) and thermogravimetric analysis (TGA). The XRD results showed that at the content of 1.0 wt % Organo Montmorillonite (OMMT) for two techniques and 3.0 wt % OMMT for the in situ polymerization technique, the OMMT was well-intercalated, exfoliated and dispersed into polyimide matrix. The OMMT agglomerated when its amount exceeded 10 wt % and 3.0 wt % for solution-dispersion and in situ polymerization techniques respectively. These results were confirmed by the TEM images of the prepared PI/MMT NCs. The TGA thermograms indicated that thermal stability of prepared PI/MMT NCs were increased with the increase of loading that, the effect is higher for the samples prepared by in situ polymerization technique.

Tropical Natural Fibres and Their Properties

In this chapter, a background of the importance of natural fibres is presented. The advantages and disadvantages of tropical natural fibres are listed. The chapter elaborates seven types of tropical natural fibres commonly being studied and used. The information about fibre extraction process, the application of fibres and other important topics are discussed.

Condition Structural Index using Principal Component Analysis for undamaged, damage and repair conditions of carbon fiber–reinforced plastic laminate

This article deals with the data reduction technique using the principal component analysis applied to the carbon fiber–reinforced plastic panels for structural health monitoring approaches. Two carbon fiber–reinforced plastic panels subjected to damage and repair coincide with typical aircraft repair procedures found in the aircraft structural repair manual. The panels were simulated with 30 mm diameter of partial and full penetration damages using a diamond-coated router. The data (50 observations) were captured for the undamaged, damaged, and repaired conditions by placing lead zirconate titanate smart sensors at 100 mm across the damaged and repaired structures. A time-based data response was captured for post analysis during the interrogation on the structure at each condition. The raw data were captured in a Lamb waveform, and the interested features were extracted using Morlet wavelet analysis to evaluate the Condition Structural Index and Amplitude-Based Assessment for each condition retrieved from the Gaussian-like distribution. The results were evaluated using the principal component analysis technique in order to distinguish the characteristic of the undamaged, damaged, and repaired conditions. The results showed that in all cases considered, it was possible to distinguish the conditions of undamaged, damaged, and repaired states with promising accuracy and repeatability of the data.

Mechanical Failure of Materials

This chapter describes the major causes of mechanical failure of the engineering components or structure. Various level of materials performance is introduced. Failures due to fracture, fatigue, creep, wear and corrosion have been explained in order to understand the common mechanical failure. A case study on the failure analysis of an electrical disconnector has been presented with the recommendation to prevent the failure.

Pre-treatment by water retting to improve the interfacial bonding strength of sugar palm fibre reinforced epoxy composite

Polymer composites using natural fibres as the reinforcing agents have found their use in many applications. However, they do suffer from a few limitations, due to the hydrophilicity of the natural fibres which results in low compatibility with the hydrophobic polymer matrices. This paper presents the alternative low-cost methods of sugar palm (Arenga pinnata) fibre surface treatments to improve the fibre-matrix interfacial adhesion. Fibre surface modifications were carried out by water retting process where the fibres were immersed in sea water, pond water and sewage water for the period of 30 days. The results showed that the tensile and flexural strengths of the treated fibre reinforced composites increased as the fibre treatment duration increased. This indicates that the treatments had significantly improved the fibre-matrix bonding strength.

Life Cycle Assessment of Natural Fiber Polymer Composites

Widespread environmental awareness towards achieving product sustainability has spurred great efforts in using more environmental-friendly materials in product design. Among the most promising solutions to address the needs is by using natural fibers to reduce the dependence on synthetic fibers as reinforcement and filler materials for polymer composites’ construction. Many efforts have been made to fully quantify the advantages of natural fiber composites (NFC) for diverse applications such as automotive, building materials, and household appliances. Life cycle assessment (LCA) is among the efforts being undertaken related to NFC with the primary aim to determine the overall potential environmental impact of using such materials on the surroundings. Among the major advantages of performing LCA is its capability to provide a more holistic overview of the environmental impact whereby it covers the whole product life cycles from raw material extraction to end-of-life stages, hence enabling justified decisions on the suitability of using NFC for specific applications to be made scientifically. In this chapter, an overview of the LCA method is explained and subsequently followed by description of its applications involving NFC in different applications. The advantages and limitations of the LCA method related to the NFCs are also discussed as well as a final conclusion on the future directions of LCA application for NFC.

Natural fiber composites

The increasing prices of petroleum, combined with the depletion of their resources, have resulted in a new trend to utilize new natural resources, as well as the bio-based composites. These composites are based on renewable plants and agricultural stocks. The natural fiber composites have now a wide range of applications. However, various issues can influence their characteristics and performance. This chapter presents information on natural fibers that are available as reinforcements for polymeric-based composites. It also provides details on natural fiber composites, such as their advantages and drawbacks, matrix system, fiber and matrix interfacial bonding, including mechanical, thermal, environmental, chemical and physical properties of natural fiber composites and their applications. This chapter, moreover, discusses the challenging task of expanding the applications of natural fiber composites for several industrial applications.