The glass temperature of dendritic polymers

Abstract

A theoretical treatment of the glass temperature of dendritic polymers is presented. The influences of polymer backbone, end group, initiator core, branching unit, composition and functionality are discussed. In dendritic polymers the glass temperature is dependent only on the generation number of dendritic growth and thus only on the molecular weight of a dendron, but not on the molecular weight of the whole molecule. It is governed primarily by the backbone glass temperature and depends little on branching functionality. Only minor differences between linear polymer and dendrite are obtained, since the influences of end groups and branching compensate each other to a large extent. 0 1995 John Wiley & Sons, Inc.

Modification and Methacrylation of Some New Aliphatic Hyperbranched Polyester Polyols Based on 1,3,5-Tris(2-hydroxyethyl) Cyanuric Acid (THECA) as a Core

“…It has been reported that the T g of dendrimers is dependent on the rigidity of the backbone and the nature of the terminal groups [17]. A marked increase in T g was detected for the samples modified with trimellitic anhydride which contradicts the results reported by Qui et al [16].…”

Influence of End Groups on Dendrimer Rheology and Conformation

“…The behavior for a given type of end group is consistent earlier studies of dendrimer glass transitions. 9,13,14 These studies showed that the T g of a dendrimer increases with molecular weight for the first few generations but reaches a plateau around generation 4, above which the T g is essentially constant.…”

Molecular relaxations in ester-terminated, amide-based dendrimers

“…While most available literature has focused on synthetic routes to these materials, physical characterization, is far from complete. Several investigations of glass-transition temperatures (T g ) in dendrimers [3][4][5][6] and hyperbranched structures [7][8][9] have correlated T g s to the number of chain ends, number of monomer units, molecular weight, and chain end composition. Crystalline 4 and liquid-crystalline 5,10,11 states in these highly branched macromolecules have also been characterized; however, studies probing the viscoelastic nature of these structures (translational, segmental, and side-chain mobility) are sparse.…”