What is the unit of average molecular weight?
What is the unit of average molecular weight?
A gram molecular weight, or gram-mole, is the amount of polymer whose weight in grams is numerically equal to the molecular weight (in amu).
How can we determine the viscosity average molecular weight?
Viscosity average molecular weight (Mv): The viscosity average molecular weight is obtained form the measurement of viscosity and is given by- Page 5 CHEM3020: POLYMER CHEMISTRY UNIT-4 Molecular weight of polymers Where Ni is the number of molecules of molecular weight Mi, α is the exponent in the Mark-Howkin-Sakurada …
What is the relation between molecular weight and viscosity?
The limiting or intrinsic viscosity [η], quantity is related to the molecular weight of the polymer by the semi-empirical Mark-Houwink equation,(1) [ η ] = K M v α where K and α are constants for a given polymer, solvent and temperature.
What is molecular weight MP?
Mp is the molecular weight corresponding to that of the maximum of the chromatographic peak. Peak-position calibration using narrow MWD polystyrene standards (PS) of different molecular weights was also per- formed. The MW of polystyrene standards were 210500, 28500, 10850, 5460, and 2050 (Polymer Laboratories).
What is viscosity method?
Viscosity can also be measured by applying oscillating vibrations to the sample and monitoring the damping effects of the fluid. These can be assessed by monitoring power input, the decay time of oscillations, or changes in the resonated frequency.
Is MW the same as Mr?
The molecular mass (abbreviated Mr) of a substance, formerly also called molecular weight and abbreviated as MW, is the mass of one molecule of that substance, relative to the unified atomic mass unit u (equal to 1/12 the mass of one atom of carbon-12).
How does molecular weight affect on viscosity?
Resistance of a liquid to flow is called viscosity. It is related to the ease with which molecules can move past each other. Viscosity increases with stronger intermolecular forces caused by increase in the molecular weight, and decreases with higher temperature.
How molecular weight averages are calculated?
The number average molecular mass is the ordinary arithmetic mean or average of the molecular masses of the individual macromolecules. It is determined by measuring the molecular mass of n polymer molecules, summing the masses, and dividing by n .
Are viscosity and molecular weight (MW) related?
You should check the viscosity average molecular weight and number average molecular weight by GPC. This will confirm the relativity of viscosity and molecular weight. Always viscosity is related to MW. Assuming the wt% of the solute is the same throughout the different samples, yes . The viscosity as a general rule should be proportional to the MW.
Is viscosity related to weight?
In general viscosity is related to molecular weight . It increases with increase in mol. weight. Polymers melts – melt flow index (as PMMA), however polymer solutions by traditional cheap…