Consequences of linking charged and uncharged monomers to binary copolymers studied in dilute solution. Part II: Non-additivity effects in the viscometric behavior. (March 2017)

• Record Type: Journal Article
• Authors: Bercea, Maria; Wolf, Bernhard A.
• Is Part Of: European polymer journal. Volume 88(2017)
• Page Start: 422
• Page End: 432
• Publication Date: 2017-03
• Subjects: Intrinsic viscosity -- Charged block copolymers -- Aqueous solution -- Extra salt effect; Polymers -- Periodicals; Polymerization -- Periodicals; Polymères -- Périodiques; Polymérisation -- Périodiques; Polymerization; Polymers; Periodicals; Electronic journals; 547.705
• DOI: 10.1016/j.eurpolymj.2016.12.007
• Languages: English
• ISSNs: 0014-3057

Abstract

Graphical abstract: Segregation ( σ > 0) or clustering ( σ < 0) of uncharged and charged monomers in isolated coils; R = N, N-dimethyl aminoethyl methacrylate, R + = [2-(methacryloyloxy)ethyl] trimethylammonium iodide. Highlights: Uncharged and charged block copolymers were studied in aqueous solution by viscometry. Non-additivity effects upon the formation of binary copolymers from dissimilar monomers. Effects of extra salt in the case of the charged copolymers was investigated. Segregation or clustering of uncharged and charged monomers in isolated coils is discussed. Abstract: Copolymers of ethylene oxide (EO) and N, N -dimethyl aminoethyl methacrylate (R) or [2-(methacryloyloxy)ethyl] trimethylammonium iodide (R + ) were studied in dilute solution: P ( EO p – b – R n ) ( I ), P(R n (1− f ) – ran – R + n f ) ( II ), and P ( EO p – b – R n + ) ( III ) ; n and p give the numbers of monomers and f is the degree of charging. ForII (variable f ) andIII (variable n ) the effects of charging on the intrinsic viscosities [ η ] are well described by Boltzmann sigmoids. The deviation of [ η ] from [ η ] add (calculated from the corresponding homopolymer data, assuming additivity of the individual contributions) are quantified by σ = [ η ] / [ η ] add - 1 measuring the segregation ( σ > 0 ) or clustering ( σ < 0 ) of dissimilar monomers in isolated coils. ForII, σ changes from negative at low f to positive at high f .I andIII pass maxima as n becomes larger, where σ is positive at low and negative at high n forI, but always larger than zero forIII . The investigation of salt effects using NaCl, CaCl2 and NaI corroborates the observations for the homopolymers.