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Thermophysical property modifications in functional polymers via lanthanide trichloride hydrates
Author(s) -
Belfiore Laurence A.,
Ruzmaikina Izolda Y.,
Das Pronab K.
Publication year - 2001
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.10821
Subject(s) - lanthanide , lutetium , europium , materials science , methacrylic acid , polymer chemistry , glass transition , lanthanum , inorganic chemistry , polymer , denticity , metal , chemistry , copolymer , organic chemistry , ion , yttrium , oxide
Fourteen water‐soluble trivalent metal chlorides from lanthanum to lutetium in the 1st‐row of the f‐block form complexes with poly(vinylamine) and increase the glass transition temperature from 57°C to well above 100°C at very low molar concentrations of the lanthanide. The large ionic radii of these hard‐acid cations allow several hard‐base amino sidegroups in the polymer to occupy sites in the first shell coordination sphere via ion‐dipole (i.e., electrostatic) interactions, which leads to microclustering of the ligands about a single metal center. The enhancement in the glass transition temperature is explained in terms of multi‐functional coordination crosslinklng. f‐Block salts induce larger increases in T g , relative to transition metal‐complexes from the d‐block, however CoCl 2 (H 2 O) 6 performs comparably to some of the more efficient lanthanides. Blends of poly(vinylamine) and trimethoxysilyl‐propylpoly(ethylene imine)hydrochloride form complexes with europium(III) and exhibit synergistic single T g response. Since lanthanides form very stable complexes with chelating (i.e., bidentate) oxygen ligands, it is possible to increase the elastic modulus of commercially important copolymers of ethylene and methacrylic acid via Eu 3+ complexation with the carboxylate anion. This claim is verified by infrared spectroscopy. Temperature and pH‐sensitive applications for drug delivery and removal of contaminants from wastewater streams should increase the utility of these lanthanide complexes.