Related Experiment Video
Updated: Aug 25, 2026
Synthesis of Soft Polysiloxane-urea Elastomers for Intraocular Lens Application
Published on: March 8, 2019
Physical and mechanical properties of PMMA resins containing gamma-methacryloxypropyltrimethoxysilane
1Department of Biomaterials Science, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan. einak@dentb.kagoshima-u.ac.jp
Abstract:
The polymethylmethacrylate (PMMA) resins containing gamma-methacryloxypropyltrimethoxysilane (gamma -MPS) of 0, 2, 4, 6, 10, 15, 20 and 30 mo1%, added to methylmethacrylate, were prepared using a monomer-polymer technique and stored in air or water at 37 +/- 0.5 degrees C for 28 days. The flexural strength and flexural modulus of the PMMA resins containing gamma -MPS of 20 and 30 mo1% were significantly smaller than those containing 2-6 mo1% and the same statements were true for the adhesive strength to porcelain tooth. However, its value of adhesive strength to Co-Cr alloy was remarkably less than to porcelain tooth. By contrast, there was no significant difference among the Knoop hardness of the PMMA resins examined. On the other hand, the thermal expansion had an increasing tendency with an increase of a gamma -MPS content. The dynamic shear modulus within a temperature measured (20-140 degrees C) decreased s1ightly as the gamma -MPS content of the PMMA resins increased, and the peak temperature of mechanical loss tangent also tended to decrease. These results indicated that the PMMA resin containing gamma -MPS of 6 mol% was the best composition from the standpoint of an excellent adhesive strength against porcelain, although its water absorption was 1.9 times that of PMMA.
Insights
The best polymethylmethacrylate (PMMA) resin for dental applications contains 6 mol% gamma-methacryloxypropyltrimethoxysilane (gamma-MPS), offering excellent adhesive strength to porcelain. Higher gamma-MPS concentrations reduced strength but improved thermal expansion.
Area of Science:
- Materials Science
- Polymer Chemistry
- Biomaterials Engineering
Background:
- Polymethylmethacrylate (PMMA) is a widely used dental material.
- Improving the mechanical properties and adhesion of PMMA is crucial for dental restorations.
- Gamma-methacryloxypropyltrimethoxysilane (gamma-MPS) is a silane coupling agent explored for enhancing polymer properties.
Purpose of the Study:
- To investigate the effect of varying gamma-MPS concentrations on the physical and mechanical properties of PMMA resins.
- To determine the optimal gamma-MPS content for improved adhesive strength, particularly to porcelain.
- To evaluate the impact of gamma-MPS on flexural strength, modulus, hardness, thermal expansion, and water absorption.
Main Methods:
- PMMA resins with 0-30 mol% gamma-MPS were synthesized using a monomer-polymer technique.
- Specimens were stored in air or water at 37°C for 28 days.
- Evaluated properties included flexural strength, flexural modulus, adhesive strength to porcelain and Co-Cr alloy, Knoop hardness, thermal expansion, and dynamic mechanical analysis (DMA).
Main Results:
- PMMA resins with 20-30 mol% gamma-MPS showed significantly lower flexural strength and modulus compared to those with 2-6 mol% gamma-MPS.
- Adhesive strength to porcelain was highest for PMMA with 6 mol% gamma-MPS, while adhesive strength to Co-Cr alloy was consistently lower than to porcelain.
- Knoop hardness remained largely unaffected, but thermal expansion increased with higher gamma-MPS content. Dynamic shear modulus decreased and the peak temperature of the mechanical loss tangent tended to decrease with increasing gamma-MPS.
Conclusions:
- The optimal composition for excellent adhesive strength to porcelain is PMMA with 6 mol% gamma-MPS.
- While this composition enhances adhesion, it also results in approximately 1.9 times higher water absorption compared to pure PMMA.
- Higher gamma-MPS concentrations negatively impact mechanical strength and modulus, suggesting a trade-off between adhesion and other material properties.
