In: Mechanical Engineering
If the bond stiffness and bond length of the carbon to carbon bond are 90 N/M and 154 pm respectively estimate the youngs modulus of diamond. B) The structure of thermoplastics also contain many carbon to carbon bonds, but the elastic moduli of thermo =plastics are commmonly two orders of magnitude lower than that of diamond. Why?
The structure of thermoplatic is such that these materials have many intramolecular covalent bonds because of presence of carbon, but they also have secondary bond with weak VANDERWAL FORCE which can be easily broken down by heat and they also interact through intramolecular and intermolecular VAN DER WALL'S bond and we know that vanderwal bonds are weaker than covalent bonds and DIAMOND is a covalent solid in which carbon atoms form a tetrahedral lattice which interact through covalent bond which are very much stronger than vanderwaal bond .thats why elastic modulus of thermoplastic are lower than that of diamomd..