【Basic Knowledge of Glossary Explanations for “Polymers and Materials”-010】Glossary explanations related to polymers
Thread Content
1. Melting range: Crystalline polymers have a wide range of melting temperatures, and this range is known as the melting range. 2. Melting point: The temperature at which the crystalline portion of the polymer melts completely. 3. Shear viscosity: The internal frictional force within a liquid that resists thin-layer flow under the action of shear stress is known as shear viscosity. 4. Yield of polymers: The plastic deformation of polymers under external forces. 5. Time-temperature equivalence principle: Raising the temperature or extending the time has an equivalent effect on molecular motion and the viscoelastic behavior of polymers; a conversion factor αT can be used to transform mechanical data measured at one temperature into those at another temperature.
I’ve learned it, thanks to the original poster for sharing! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !
Do molecules with a higher molecular weight have a higher melting point?
The difference between various aggregation states of molecules is essentially a difference in energy. The higher the energy, the more intense the thermal motion of the molecules, and correspondingly, the greater the distance between them; this gives rise to solid, liquid, and gas states (of course, in addition to these three states, there is also the newly discovered liquid crystal state). Molecular motion requires an energy source, and the larger the molecular weight, the more energy is generally needed. Therefore, as a rule, the greater the molecular weight of a crystal, the higher its melting and boiling points.
This post was last edited by Their crimes have finally come to light on 2015-8-11 10:22. Are there any special circumstances?