2004 Fiscal Year Final Research Report Summary
Development of New Tissue Conditioners used poly (butyl methacrylate)
| Project/Area Number |
15592041
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
補綴理工系歯学
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| Research Institution | Tohoku University |
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Principal Investigator |
KATAKURA Naoyuki Tohoku University, Graduate School of Dentistry, Associate Professor, 大学院・歯学研究科, 助教授 (70005031)
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| Co-Investigator(Kenkyū-buntansha) |
IZUMIDA Akio Tohoku University, Graduate School of Dentistry, Research Associate, 大学院・歯学研究科, 助手 (40333827)
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| Project Period (FY) |
2003 – 2004
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| Keywords | Tissue conditioner / Copolymer / Poly (isobutyl methacrylate) / Plasticizer / Dibutyl sebacate / Rheology / Flow property / Dynamic viscoelasticity |
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| Research Abstract |
The purpose of this study was to develop the new tissue conditioners, which consist of poly (butyl methacrylate) and the liquid plasticizer without an endocrine disrupter.
1.Syntheses of polymers
Homopolymers (isoPBMA, PEMA) and copolymer of isobutyl methacrylate (isoBMA) and ethyl methacrylate (EMA) were synthesized by suspension polymerization in aqueous gelatin.
2.Particle size and molecular weight of polymers
The particle size of polymer powder is related to flow properties and gelation time of powder/liquid mixtures. The particle sizes of polymer powders of isoPBMA, PEMA, and copolymer were 32μm, 29μm, and 35μm, respectively. The molecular weight of polymer is related to viscoelastic properties of powder/liquid mixtures after gelation. The weight average molecular weight. of isoPBMA and copolymer was 280,000, and that of PEMAwas 210,000.
3.Flow properties of powder and liquid mixtures
The viscosity-time curves of mixtures of copolymer powder and plasticizer dibutyl sebacate (DBS) containing ethanol were measured by the cone-plate viscometer. After two or three minutes, the viscosities of mixtures increased rapidly with gelation. It was found that ethanol content of 13〜15% and powder/liquid ratio of 1.3〜1.4 were useful and practical for a tissue conditioner.
4.Dynamic viscoelasticity of powder and liquid mixtures
The viscoelastic properties of mixtures of copolymer powder and DBS containing 13% ethanol after gelation were investigated by the dynamic method. The viscoelastic data of storage modulus G' and loss tangent tan δ versus frequencies at different temperatures were superimposed to a master curve by application of the time-temperature superposition principle. These viscoelastic properties of new experimental materials were similar to those of a commercially available tissue conditioner. This study indicates that a new tissue conditioner without an endocrine disrupter can be made by use of copolymer and DBS.
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