251. A hydroxyl-containing hyperbranched polymer as a multi-purpose modifier for a dental epoxy.
- Author
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Xing, An, Sun, Qiannan, Meng, Yan, Zhang, Yongyi, Li, Xiaoyu, and Han, Bing
- Subjects
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DENTAL resins , *GLASS transition temperature , *DENTAL materials , *EPOXY resins , *FLEXURAL strength , *POLYMERS , *BISPHENOL A , *EPOXY coatings - Abstract
Despite the high cure shrinkage, inadequate degree of cure, and toxicity, dimethacrylate dental resins have remained the dominant matrices for dental composites. Bisphenol-A free cycloaliphatic epoxy resins have lower shrinkages due to the ring-opening nature; however, its mechanical strength needs to be improved. In order to reduce cure shrinkage and toxicity simultaneously improve mechanical strength, which has long been a challenge, a hydroxyl-containing hyperbranched polymer (HBP–OH) was synthesized and used as a multi-purpose modifier for a cycloaliphatic dental epoxy system. Results show that cure shrinkage of neat dental epoxy (3.46%) is about half of that of the dimethacrylate dental resin (7.65%); HBP–OH modified epoxy further reduces shrinkage to ca. 2%. Addition of HBP–OH also reduces cytotoxicity and increases the flexural strength. Addition of 7 wt% HBP–OH increases the flexural strength of the dental epoxy from 90.8 to 109.8 MPa. In addition, effects of HBP–OH addition on the reactivity, glass transition temperature, and water uptake were also reported. Results suggest that HBP–OH shows great potentials as a multi-purpose modifier for dental epoxy resins. Unlabelled Image • Addition of HBP–OH simultaneously improved several properties of the dental epoxy. • Addition of HBP–OH further reduced the cure shrinkage of dental epoxy to ca. 2%. • The cytotoxicity of cured dental epoxy was effectively reduced by adding HBP–OH. • The flexural strength of curing system was also improved. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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