Polyethylmethacrylate in dilute solution

Karunakaran, K. ; Santappa, M. (1968) Polyethylmethacrylate in dilute solution Die Makromolekulare Chemie, 111 (1). pp. 20-35. ISSN 0025-116X

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Official URL: http://onlinelibrary.wiley.com/doi/10.1002/macp.19...

Related URL: http://dx.doi.org/10.1002/macp.1968.021110103


Polyethylmethacrylate (PEM) was prepared by bulk polymerization and fractionated using acetone/acetone-water (2:1 V/V) mixture. The solution properties of fractionated as well as unfractionated polymers were investigated in various solvents (ethylacetabte, toluene, ethylacetate-ethanol) by light scattering and viscosity at 35°C. Osmotic pressure measurements were also carried out on selected polymer samples for the evaluation of width of distribution. [η]-Mw and (r2)½-Mw relationships for these systems were established. Ethylacetate was found to be a bad solvent compared to toluene and methylethyketone. In the case of unfractionated PEM, the parameters like [η]M, Mw/[Φ], and φ were corrected for molecular weight heterogeneity assuming SCHULZ-ZIMM distribution. For the evaluation of FLORY's constant K, and the unperturbed dimension (r02)½ of the polymer, FLORY-FOX, KURATA-STOCKMAYER, and STOCKMAYER-FIXMAN methods were employed. The K and (r02)½ values evaluated from the FLORY-FOX method were almost similar to those measured in a θ solvent, while the other two methods yielded higher values. A comparison of the measured (r2)w½ and that calculated from KIRKWOOD-RISEMAN and DEBYE-BUECHE theories indicated the polymer coil as conforming to a statistical chain. The molecular weight dependence of A2, the second virial coefficient, for PEM/ethylacetate was established and the value of A2 compared well with that calculated from OROFINO-FLORY equation.

Item Type:Article
Source:Copyright of this article belongs to Huthig & Wepf Verlag, Basel.
ID Code:43347
Deposited On:11 Jun 2011 08:34
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