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Yield stress of polymethyl methacrylate subjected to vacuum UV radiation is function of strain rate, tensile test temperature and irradiation dose
Specific heat of amorphous polymethyl methacrylate and polystyrene by pulse method below 4 K, comparing Debye and acoustic values
A procedure is described for the fabrication of complex computer-generated phase holograms in polymethyl methacrylate (PMMA) by means of partial-exposure e-beam lithography and subsequent carefully controlled partial development. Following the development, the pattern appears (rendered in relief) in the PMMA, which then acts as the phase-delay medium. The devices fabricated were designed with 16 equal phase steps per retardation cycle, were up to 3 mm square, and consisted of up to 10 millions of 0.3-2.0-micron square pixels. Data files were up to 60 Mb-long, and the exposure times ranged to several hours. A Fresnel phase lens was fabricated with a diffraction-limited optical performance of 83-percent efficiency.
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Electrokinetic deposition of methylmethacrylate is used to mitigate corrosion in reinforced concrete. The methylmethacrylate (MMA) monomer deposits in the pores in the concrete where it is converted into its polymer, polymethylmethacrylate, thus creating a barrier that also enhances the mechanical properties of the concrete. Previous to the MMA treatment an Electrokinetic deposition is used to transport calcium, sodium and potassium hydroxide particles through the capillary pores of concrete directly to the concrete reinforcement. The intent is to use these compounds as a sacrificial electrode layer during the electrokinetic deposition of methylmethacrylate monomer. Cylindrical reinforced concrete specimens were subjected to electrokinetic treatment and the specimens were tested to characterize porosity reduction and tensile splitting strength showing an increase in the tensile strength. In addition, nine specimens treated electro-kinetically and in long-term atmospheric exposure testing at NASA's Kennedy Space Center, seaside atmospheric exposure test site were tested to determine their corrosion rate.
The loss of strength of cast polymethyl methacrylate plastic as a result of crazing is of considerable importance to the aircraft industry. Because of the critical need for basic information on the nature of crazing and the effects of various treatments and environmental conditions on its incidence and magnitude, an investigation of this phenomenon was undertaken. The following factors were examined: (1) the effect of stress-solvent crazing on tensile strength of polymethyl methacrylate; (2) the critical stress and strain for onset of crazing at various temperatures; (3) the effect of molecular weight on crazing; and (4) the effect of multiaxial stretching on crazing of polymethyl methacrylate and other acrylic glazing materials.
Stress craze development into cracks and fractures of polymethyl methacrylate bars
Glass transition temperature of polymethyl methacrylate as affected by low concentrations of monomer and diethyl phthalate plasticizers
Mechanical properties determined for cross linked polymethyl methacrylate under stress-relaxation test method
Mechanical properties of cross linked polymethyl methacrylate polymers in space environment - tensile stress-strain data, and stress relaxation and swelling measurements
Yield stress master curves for polymethyl methacrylate, polystyrene, polyvinyl chloride and polyethylene terephthalate below glass transition temperature - polymer chemistry
Plastic yield behavior of polystyrene and polymethyl methacrylate
Measurement gage provides instant visual indication of water depth based on capillary action and light diffraction in a group of solid, highly polished polymethyl methacrylate rods. Rod lengths are adjustable to measure various water depths in any desired increments.
Development and testing of ballistic shock loading device with projectile for producing stress waves in polymethyl methacrylate rods
Rapid linear pyrolysis of polymethyl methacrylate
Studying mechanism of flame spreading over surface of igniting polystyrene and polymethyl methacrylate for minimizing fire hazard in space capsules