Polymers with terminal amine or phosphite groups (X) were synthesized from tosylated derivatives of hydrogenated alpha-hydroxy- and alpha, omega-dihydroxy-poly-1,3-butadienes, produced by anionic techniques. Products are semi-telechelic and telechelic polymers with X = NH2 (5), NHPh (6), NHPr " (7), NH(CH2)(3)NMe2 (8), O(CH2)(2)NH2 (9), O(CH2)(2)NH(CH2)(2)NH2 (10), NMe2 (13), OPO2C6H4 (14) of varying ethyl side-group content, controlled molar mass ((M) over bar(n) = 600-3000) and low polydispersity. Characterization of polymers by n.m.r. and i.r. spectroscopy is reported, with comparative studies on short chain model systems. Thermal properties and viscosities have been investigated in relation to molar mass, backbone structure and terminal functionality; comparisons are made with related saturated and unsaturated systems, and with polymers containing terminal ionic functionalities, formed by alkylation, protonation, or coordination with Cu(II), Ni(II) and Fe(III) chlorides. Effects of end-groups on variations in Tg, higher thermal transitions and on melt viscosities are discussed. Oxidation of phosphite end-groups is also observed.