Polystyrene (PS) is a synthetic organic polymer made from the polymerization of styrene monomers. Polystyrene comes in solid pieces or foamed articles. General purpose polystyrene is a clear, hard, and brittle plastic. Since it is relatively inexpensive, it has become the one of the most widely used polymer in the industry. Applications include insulation sheets, construction supplies, shipping peanuts, various food/kitchen containers and disposable table wares. Solution Viscosity is a key property control in the manufacturing process. The purpose of this App Note is to demonstrate the repeatability of the HMJ DSV technique. The samples were analyzed using an HMJ Y501 Dual Capillary Relative Viscometer system. The analysis conditions are listed below.

Solvent	THF
Sample Concentration	0.5 g/dL
Prep Temperature	25C
Dissolution Time	60 Minutes
Analysis Temperature	30C

RSD of DSV data is typically less than 1% and the following data supports that claim.

Samples	IV (dL/g)		Samples	IV (dL/g)
			Value
PS-1A	0.8321		PS-3A	0.8372
PS-1B	0.8425		PS-3B	0.8363
PS-2A	0.8358		PS-4A	0.8402
PS-2B	0.8366		PS-4B	0.8401

Average = 0.8376 SD = 0.0032 RSD = 0.39%

In addition to the precision of the data demonstrated above, the DSV technique presents an easy opportunity to automate a rather laborious solution viscosity measurement. Automation can range from a simple autosampler system to fully automated Vortex operation.