In:
Journal of Polymer Engineering, Walter de Gruyter GmbH, Vol. 34, No. 7 ( 2014-9-1), p. 605-609
Abstract:
Different generation hyperbranched polyurethanes (HBPUs) were synthesized through the A 2 +B’B 2 strategy. The molecular structures and viscosity were characterized by nuclear magnetic resonance (NMR) spectroscopy and gel permeation chromatography (GPC). The NMR results confirmed the formation of the branched units between the segments contained in the HBPU structure. The GPC with a four-capillary bridge design differential viscometer and the Ubbelohde viscometer showed a different viscosity. For the HBPUs, the viscosity first increased to higher values then decreased to lower values, and finally increased with increasing weight, which can be attributed to the spherical structure. The growth degree of HBPUs spherical structure depends on the forming hydrogen bonds; when the hydrogen bonds reach a certain degree, the spherical structure becomes compact.
Type of Medium:
Online Resource
ISSN:
2191-0340
,
0334-6447
DOI:
10.1515/polyeng-2013-0312
Language:
English
Publisher:
Walter de Gruyter GmbH
Publication Date:
2014
detail.hit.zdb_id:
2602430-5
Permalink