title: Effect of pH on the physico-mechanical properties and miscibility of methyl cellulose/poly(acrylic acid) blends.
abstract: The miscibility behavior and physico-mechanical properties between methyl cellulose (MC) of different molecular weights (4 × 10(4) and 8.3 × 10(4)g/mol) and poly(acrylic acid) (PAA) were studied by viscometry, differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), tensile strength and scanning electron microscopy (SEM) using water as a solvent. Various formulations were designed to investigate the effects of process variables such as pH on the physico-mechanical and miscibility properties of MC/PAA blends. The rheological features for the obtained blends are strongly dependent on the molecular weight of the MC used and pH. The viscosity measurements showed that all blends have non-Newtonian shear thinning (pseudoplastic) behavior. These blends have a single glass transition indicating that these blends are able to form a miscible phase due to the formation of hydrogen bonds between the hydroxyl group of MC and the carboxyl group of PAA. The MC/PAA blends exhibit good mechanical properties, thermal stability, characteristics of a MC-PAA polymer network. SEM of the blends showed no phase separation, when compared with the pure MC and PAA.
authors.affiliation: Faculty of Science and Engineering, University of Wolverhampton, Wulfruna Street, Wolverhampton, West Midlands WV1 1LY, UK. Electronic address: elashmawi5@yahoo.com.
authors.forename: E S M
authors.initials: ES
authors.lastname: Negim
authors.forename: Zh A
authors.initials: ZhA
authors.lastname: Nurpeissova
authors.forename: R A
authors.initials: RA
authors.lastname: Mangazbayeva
authors.forename: J M
authors.initials: JM
authors.lastname: Khatib
authors.forename: C
authors.initials: C
authors.lastname: Williams
authors.forename: G A
authors.initials: GA
authors.lastname: Mun
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008747:Methylcellulose / Q000737:chemistry*; D055585:Physical Phenomena; D012212:Rheology; D013718:Tensile Strength
chemical_list: D000180:Acrylic Resins; C006903:carbopol 940; D008747:Methylcellulose
keywords: Interpolymer complexes; Methyl cellulose; Miscible blends; Rheology