Development of polyamide matrix composites for automotive industries

In recent years, composite materials have been developed in the automotive industry, as in many areas of industry, because of their advantages such as light weight, ease of processing, good corrosion resistance, high mechanical strength and low production cost. The aim of the present study is to improve the properties of polyamide (PA), which is an ideal material for many automobile components such as radiator components, filter housings, interconnect components, cables, seat belt components, airbag and pedals. As a consequence of the study, composite films with improved mechanical and dielectric properties were developed by incorporation of cellulose acetate (CA) biopolymer and inorganic calcium carbonate (CaCO3) into the PA matrix. Ca(NO3)24H2O (KN) was used as the starting material and CaCO3 nanoparticle synthesis processes were conducted by sol-gel citrate method under different synthesis conditions. CaCO3 nanoparticles with homogeneous size distribution were synthesized using citric acid instead of toxic and corrosive chemicals such as hydrazine, which is generally used as a reducing agent in nanoparticle synthesis. The chemical structure of the synthesized CaCO3 nanoparticles was characterized by Fourier transform infrared spectroscopy (FTIR) and the crystal structure was examined by X-ray diffraction (XRD) method. Besides, morphology and size distributions of the synthesized nanoparticles were analyzed by scanning electron microscopy (SEM). Consequently, among the nanoparticles, synthesized under distinct synthesis conditions, the one, synthesized at 125oC and with a SA:KN mole ratio of 0.75:1, were found to exhibit a homogeneous size distribution between 1-100 nm and used as an additive in polymer matrix composite production. The strong interactions between the components of the composite material were investigated by FTIR. Mechanical properties, and thermal degradation behavior of the composite materials were investigated by SEM, tensile tests, and thermogravimetric analysis (TGA), respectively. Based on the tensile tests, it was concluded that a composite film with a tensile strength of 2.2 times that of pure PA film was developed. Also, it was concluded that a composite film with a dielectric constant of 26% higher than that of pure PA film, were developed according to the dielectric constant measurements. Keywords: Composite, Nanocomposite, Polyamide, Calcium carbonate, Cellulose acetate