Polymer, Vol.161, 190-196, 2019
Tailoring the temperature-dependent viscoelastic behavior of acrylic copolymers by introducing hydrogen bonding interactions
A great challenge of toner design is to improve the storage stability and energy saving. The reciprocal characteristics of endowing high glass transition temperature (T-g) while low fusing temperature (T-f) are essential. In this study, we investigate the influence of hydrogen bonding interactions on T-g and temperature-dependent viscoelastic of styrene/ethyl acrylate random copolymers [P(St-co-EA)] with different ratios of St/EA by the incorporation of small molecule 4,4'-thio-bis(6-tert-butyl-m-methyl phenol) (AO300). The results of FTIR spectra confirm the intermolecular hydrogen bonding between the carbonyl groups of acrylic copolymers and hydroxyl groups of AO300 small molecules. With increasing AO300 content, T-g of the hybrids increases due to the increased number of hydrogen bonding. The universal scaling law of temperature-dependent viscoelastic behavior is indeed valid for pure acrylic copolymers in both the Arrhenius and non-Arrhenius regions. However, the temperature-dependent viscoelastic behaviors of the hybrids are strongly influenced by the ratio of St/EA and AO300 content, showing positive or negative deviations from the universal plot for high and low ratio of St/EA copolymer based hybrids, respectively. The systematic deviations are greater with increasing small molecule content. Such irregular deviations can be attributed to either the disassociation of hydrogen bonding or plasticizing effect by the introduction of AO300. The P(St-co-EA)/AO300 hybrids possessing high T-g and low T-f provides a promising candidate of toner binder resin to realize the storage stability and energy efficient.
Keywords:Hydrogen bonding;Glass transition;Viscoelastic behavior;Universal scaling law;Flow activation energy