Optical and mechanical properties of optically transparent poly(methyl methacrylate) composites

2004 ◽  
Vol 32 (5) ◽  
pp. 344-350 ◽  
Author(s):  
Hongy Lin ◽  
Delbert E. Day ◽  
James O. Stoffer

An optically transparent material with enhanced physical-mechanical properties was synthesized, which is based on the in situ formed sequential interpenetrating polymer networks of poly(methyl methacrylate)/polyurethane with an oligoester component. The kinetic features of polymerization of methyl methacrylate in these systems were studied. It was established that the polymerization rate of methyl methacrylate increases with an increase in the content of a polyurethane component, which results from an increase in the system viscosity. Irrespective of the content of polyurethane (15, 20 or 25 wt.%), optically transparent materials with a light transmission coefficient of about 90% were formed. The method of dynamic mechanical analysis showed that the modification of cross-linked poly(methyl methacrylate) with cross-linked polyurethane led to a decrease in the value of the elastic modulus; the value of the loss modulus being increased with an increase in polyurethane content. This indicated bot a decrease in fragility and the improvement in impact strength of the glass-like material. According to the study of physical-mechanical properties of the materials, the presence of polyurethane in their composition resulted in an increase in the impact strength and relative breaking elongation and in the reduction of the Young modulus. It was found that the interpenetrating polymer network containing 20% of polyurethane showed the best values of breaking strength, breaking elongation and Charpy impact.


2020 ◽  
Vol 54 (18) ◽  
pp. 2449-2459
Author(s):  
Ömer Bahadır Mergen ◽  
Ertan Arda ◽  
Gülşen Akın Evingür

In this study, we report the preparation of poly (methyl methacrylate)/multi-walled carbon nanotube (MWCNT) composite thin films by simple and efficient solution mixing and ultrasonic method and the electrical, optical, and mechanical characterizations. Scattered light intensity ( I sc), tensile modulus ( E), and surface conductivity ( σ) of these composites have increased with the addition of MWCNT into the composite. The observed behavior in electrical, optical, and mechanical properties of the poly (methyl methacrylate)/MWCNT composites was interpreted by site and classical percolation theory. The optical mechanical and electrical percolation thresholds of poly (methyl methacrylate)/MWCNT composites were determined as φ op = 3 wt%, φ m = 0 wt%, and φσ = 5 wt%, respectively. The optical ( t op), mechanical ( t m), and electrical ( t σ) critical exponents were calculated as 2.23, 0.43, and 0.11, respectively. Both the tensile modulus and tensile strength of poly (methyl methacrylate)/MWCNT composites were increased with increasing MWCNT content until it reaches to 10 wt%. However, above φ = 10 wt%, the mechanical properties of the composites were decreased due to the aggregation of MWCNTs, while the toughness does not show a significant change until φ = 10 wt% MWCNT content, whereas it was decreased above this value.


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