Atoms and Bonds - Lesson Summary
The two types of Atomic Bonds are primary and secondary bonds
In the study of polymers the term linear describes a type of polymer and it refers to the arrangement of the polymerization units.
Polymers consist of long molecular chains of covalently bonded atoms.
Many synthetic polymers are built from multiple structural units and these are known as copolymers.
Thermoplastics only have secondary bonds between chains as opposed to thermosets which have primary bonds.
Thermoplastic polymers can be melted and even molded whereas the Thermosets cannot be melted in a general sense.
Soft Matter includes a large variety of materials, typically composed of polymers, colloids, liquid crystals and other mesoscopic constituents.
In Soft Materials the operative length scales are intermediates between the atomic sizes and the macroscopic scales.
Van der Waals bonds arise from interactions between uncharged, weakly interacting atoms or molecules and are caused by the interaction between dipoles.
The Modulus can be thought of as the storage energy density that is in the system.
In a Perfect Crystalline Solid, there is no mechanism available on any time-scale for the stress to relax.
The Relaxation Time-scales for polymer melts or solutions can be of the order of milliseconds to seconds.