Physico-chemical properties of some Poly(methyl methacrylate) blends

Abstract

In this thesis, studies on plasticized and non-plasticized polymer blends of Poly (methyl methacrylate) (PMMA) and Cellulose acetate (CA) and its derivatives with varying blend compositions prepared by solution casting method is presented. Miscibility, water uptake, ion exchange capacity (IEC), proton conductivity and dielectric properties of these blends have been studied. Dimethyl formamide (DMF) is used as solvent. Dimethyl phthalate (DMP), Diethyl phthalate (DEP), Dipropyl phthalate (DPP), Dibutyl phthalate (DBP) and Propylene carbonate (PC) have been used as plasticizers. Fourier transform infrared spectra (FTIR) and Differential scanning calorimetric (DSC) measurements have been used to analyze the miscibility of the plasticized and non-plasticized blends. Up to PMMA with CA and its derivatives with a composition of 50/50 for both plasticized and non-plasticized blends, water uptake amount of the blends showed an increasing trend. Ion exchange capacity for both plasticized and non-plasticized blends decreased with increase in PMMA content of the blends. The variations in the blend properties have been attributed to the presence of specific interactions and exchangeable groups in the blend system. Impedance analysis has been performed in order to calculate the blend conductivity. The proton conductivity of the plasticized and non-plasticized blends is in the order of 10-3 S cm-1. The dielectric constant and dielectric loss measurements of the blends indicated the absence of any relaxation phenomenon in the blend system. Among the plasticized blend system, polymer blends with low percentage (2.5%, 5%, 7.5% and 10%) of PC, DMP, DEP, DPP and DBP have shown decreasing trend for water uptake test and an increasing trend for ion exchange capacity test as well as proton conductivity measurement. This attributes to the effect of plasticizers on the studied blend system.