Polymers and Viscosity Demystified

What's a Polymer?

A polymer is basically the consequence of organic blocks called monomers linked together by means of a solvent.Depending on the mix and proportions of crude materials and diverse response conditions, numerous sorts of polymers may be created, for example, polystyrene, polycarbonate, polyethylene and PMMA. Composition of principle crude materials and added substances also result in polymers of different grades. SMM (Polymer) is presently producing 6 distinctive PMMA grades: MH, EX, EXN, MG, LG and LG2.

What's Viscosity?

Viscosity is home of a fluid that gives resistance to its flow. Viscosity is because of the internal friction of molecules and mainly depends on the character & temperature of the liquid. 
The polymerisation reaction is conducted within specific conditions and boundaries. The quality of the PMMA polymer thus developed may be evaluated by viscosity, that will be asignificant characteristic for several materials, especially polymers. For liquids, viscosity determines flow characteristics, heat transfer and mass transfer. For polymers, viscosity is usually a measuring stick. Viscosity data is a must since it helps in predictingbehavioural properties of the polymer. Also, measurement of viscosity is essential in monitoring the SMM (Polymer) process.

Determining Viscosity

How will you determine the viscosity of a solid cube of polymer? 
Polymer viscosities can vary from 103 to 107 Poise so one testing method cannot cover them all. So, two common testing methods are used: melt and solution.

Melt Viscosity

The melt index is really a common testing technique that studies parameters like compression weight and testing temperature, predominantlyin higher viscosity polymers. Obviously, the outcome depend on the kind of polymer. For example, for the melt viscosity test of polyethylene, the analysis parameters add a temperature of 190˚ C and weight of 10 kg. Following a certain time (say 10 minutes), the extruded polymer is weighed. The melt index is then expressed as grams of polymer/10 minutes and this value corresponds to the average molecular weight of the polymer. Polyethylene comes with an average molecular weight of 150,000 g/mole and a melt index near to 0.3 / 10 minutes. 
For processes or final products where easy processing is needed, melt indices above 15 g/ 10 minutes are desirable.Where mechanical properties are essential, melt indices below 1 g/10 minutes are preferred.

Solution Viscosity

Solution viscosity testing involves dissolving the polymer in a solvent, usually followed closely by gentle heat. The perfect solution is is then allowed to visit via an apparatus such as a pipette and the travel is timed. Enough time for the pure solvent to flow through the same apparatus can also be calculated. Both of these values are then compared, producing a relative viscosity – that will be essentially the ratio of the polymer viscosity to the solvent viscosity.

While melt viscositytechnique is carried out by SMM(P) in regular frequency to guarantee the polymer formed is well in check, solution viscosity is executed by SCASS during product certification stage as one last confirmation.

Sumitomo Chemical Singapore is one of leading producers of the polymer - PMMA (Polymethyl Methacrylate), a polymer of MMA (Methyl Metacrylate Monomer).Visit us to find out more about polymers, PMMA and MMA. 

for more information kindly contact  acrylic glass