Relative strength of H‐bonding groups on biodegradable polymer‐based blends in solution

Abstract

ABSTRACT:The intermolecular hydrogen bonding interactions between poly(3-hydroxybutyrate) and poly(styrene-covinyl phenol) copolymers with mutual solvent epichlorohydrin were thoroughly investigated by steady-state fluorescence and viscosity techniques. Fluorescence spectroscopy along with viscosity technique was used to asses the intermolecular hydrogen bonding between poly-(3-hydroxybutyrate) and its blends with five copolymer samples of styrene-vinyl phenol, containing different proportions of vinyl phenol but similar average molecular weight and polydispersity index. In the case of very low OH contents (2-4 mol %), as expected, both components of poly(3-hydroxybutyrate) and poly(styrene-co-4-vinylphenol) chains are well separated and remain so independently of the mixed polymer ratio and overall polymer concentration as well. Conversely, when the OH content reaches 5.8 mol % or more, a significant decrease of the intrinsic fluorescence intensity emitted by the copolymer is detected upon addition of aliquots of poly(3-hydroxybutyrate). In these cases, an average value for the interassociation equilibrium constant, K A ϭ 8.7, was obtained using a binding model formalism. A good agreement of these results with those obtained from complementary viscosity measurements, through the interaction parameter, ⌬b, was found.

Miscibility and crystallization behavior of poly(ethylene‐co‐vinylalcohol)/poly(maleic anhydride‐alt‐ethylene) blend

“…The reduced viscosity measurements of PEVA, PEMAH, and their blends were realized at 30 C in DMF using a viscosimeter Ubbelohde Scott Gerate type Avs 310. The description of the technique used and methods of measurement have been detailed by Soria et al 19 The specific and intrinsic coefficients of each copolymer viscosity in the DMF/polymeric binary or DMF/copolymer/copolymer ternary systems have been determined by infinite-dilution extrapolation of the copolymer with the DMF/polymer binary mixture, i.e., if the system is a named solvent (S)/ copolymer(Cx)/copolymer(Cy), the values of the intrinsic coefficient of viscosity of copolymer (Cx) in a dilute solution of polymer (Cy) were obtained by zero-concentration extrapolation of Cx in a binary mixture, in which the concentration of Cx was constant.…”

Miscibility study of poly(vinyl chloride)/poly(methyl methacrylate‐co‐4‐vinylpyridine) by viscosimetry, DSC, and FTIR

“…The description of the used technique and methods of measurement have been detailed by Soria et al23 The specific and intrinsic coefficients of viscosity of each polymer or copolymer, in the chloroform/polymeric solute binary, or chloroform/copolymer/polymer ternary systems, have been determined by infinite‐dilution extrapolation of the copolymer with the chloroform/polymer binary mixture, i.e., if the system is named solvent (S)/copolymer(Cx)/polymer(P), the values of the intrinsic coefficient of viscosity of copolymer (Cx) in a dilute solution of polymer (P) are obtained by zero‐concentration extrapolation of Cx in a binary mixture, in which the concentration of P is constant.…”

Modelling the hydrogen-bonding interactions in a copolymer/biodegradable homopolymer blend through excess functions

“…The proton donor species used in the present work were poly(styrene-co-4-vinyl phenol) random copolymers (PSVPh-x.x) with different vinyl phenol content (denoted by x.x in mole%). The copolymers were synthetized in our lab according to a procedure recently described, 46 and were characterized by size-exclusion chromatography (SEC) and the phenol content determined by proton NMR spectroscopy ( 1 H-NMR) at room temperature. The proton acceptor polymer was poly(3-hydroxybutyrate) (PHB) from Aldrich Chemical Co. (Wisconsin, USA).…”