Polymethylmethacrylate plastic

The problem of high pressure drops with gel entrapped materials has been overcome by entrapping the enzymes in plastic materials snch as polystyrene and polymethylmethacrylate (Wang et al, 1997). The method involves chemical acryloylation of the enzyme to provide a polymerizable functionality, formation of non-covalent ion pairs between the enzymes and a snrfactant, solntion of these ion pairs in an organic solvent followed by addition of vii rl monomers, a crosshnker, and an initiator to give the desired vinyl polymer with the entrapped enzymes. 

Zhu et al. [76] designed and fabricated microfluidic devices on polymethylmethacrylate (PMMA) substrates for electrochemical analysis applications using an improved UY-LIGA process. The microchannel structures were transferred from a nickel mold onto the plastic plates by the hot embossing... 

In spite of Baekeland s success, it was another two decades before the Age of Polymers can really be said to have been born. The 1920s and 1930s saw the invention and/or commercialization of a number of new polymeric products ("plastics") that most consumers now consider to he essential chemicals in their lives. These products include the urea formaldehyde plastics (1923), polyvinyl chloride (PVC 1926), polystyrene (1929), nylon (1930), polymethylmethacrylate (acrylics 1931), polyethylene (1933), the melamine plastics (1933), polyvinylidene chloride (Saran 1933), polyvinyl acetate (PVA 1937), and tetrafluoroethylene (Teflon 1938). 

In comparison to bulk plastics, thermoplastic polymethylmethacrylate (PMMA) is much more expensive. Its particular characteristics are clarity, hardness, low absorbance and resistance to aqueous solutions, acids, alkalis, carbon dioxide and fat. It is attacked or dissolved by polar organic solvents. The world-wide use of PMMA in 1997 was ca. 1.2 x 106 t, principaly for optical articles in cars and buildings and glazing material in aircraft. Typical food contact articles are dishes, cups and silverware. In addition it has orthopedic and denture uses. 

Polymethylmethacrylate (acrylic) Acetone, methyl ethyl ketone, detergent, methanol, trichloroethylene, isopropanol Abrasion. Grit or vapor blast or 100-grit emery cloth followed by solvent degreasing. For maximum strength, relieve stresses by annealing plastic for 5 h at 100°C... 

A very recent series of publications by Locascio and others [54-56] demonstrated successful applications of various plastic materials, such as polydi-methylsiloxane (PDMS), polymethylmethacrylate (PMMA), copolyester, and their combinations, for assembling integrated fluidic structures to perform online sample pretreatment by affinity dialysis and concentration for fast and sensi-... 

N. Brand, Depolymerization of polymethylmethacrylate (PMMA), In Recycling and Recovery of Plastics, J. Brandrup, M. Bitmer, W. Michael and G. Menges (eds), Hanser Press, Munich 1996, pp. 488-493. 

Figure 9.14 Transmission electron micrograph of a section of bicontinuous phase formed by 53 wt% polystyrene and 47 wt% polymethylmethacrylate blended with a Brabender mixer at a rate of 20 rpm, which is roughly equivalent to 90 sec, at 200°C. At this shear rate, the two components have about the same viscosity, around 1000 Pa s. The characteristic domain width is around 1 /xm. (From Miles and Zurek 1988, reprinted with permission from the Society of Plastics Engineers.)...

The products discussed above touch us in every moment of our lives. We wake in the morning to an alarm clock in a polystyrene case we arise from our polyester blend sheets and slip on a pair of slippers glued with polyurethane glue. We flip the polymethylmethacrylate light switch and walk across a Nylon carpet to the bathroom. Our polymethylmethacrylate toothbrush is sitting on the Formica counter top. It has Nylon bristles. The soap we use to wash our face may be hydrocarbon derived sodium lauryl sulfate. We walk to the kitchen with polyvinyl chloride floors and sit at a Formica table. The polyethylene milk carton is at hand to supply the milk for the cereal stored in the polyethylene bag. It is eaten from a urea formamide bowl. The frying pan has a phenolformaldehyde plastic handle and a Teflon interior coating. 

The DRAW disc which offers the facility to make one recording consists of a plastic substrate such as polycarbonate (PC) or polymethylmethacrylate (PMMA) and a recording layer made in amorphous colourants. The thickness of the recording layer is approximately 30-100 nm. The principle of the optical DRAW disc memory, called heat mode system, is shown in Fig. 1. In this system, microscopic pits in the coloured recording layer of a disc are formed by thermal energy transformed from photo energy of a... 

Protein immobilization on solid phase has provided versatility in separation techniques and IA formats. Most proteins can be adsorbed onto plastic or glass solid-phase support surfaces (139). Cellulose acetate, cellulose nitrate, polymethylmethacrylate disk, filter paper, and other synthetic solid-phase supports have been used (140,141). Noncovalent hydrophobic, electrostatic, and hydrophilic bonds form between proteins and the surface of the solid phase (142-144). Covalent linkages between proteins and solid-phase supports can also be developed (145). Some solid-phase supports with activated surface groups are commercially avail-... 

The adhesive transfer of organic plastics has some special features of it own. Makinson and Tabor [24] observed that polytetrafluoroethylene sliding on glass left transferred material on the counter surface in the form of lumps, ribbons, sheets or very thin films, depending on the rubbing conditions. Pooley and Tabor [25], who studied the transfer process more intensively, also reported the behavior of other polymers such as fluorocarbon copolymers, polyethylene, polypropylene, polystyrene, polymethylmethacrylate and polyvinyl chloride. Descriptions of transfer in relation to wear were reported for PTFE by Tanaka tt ai. [20] and for polyethylene by Miller a.1. [21]... 

Polymethylacrylate (PMA) and polymethylmethacrylate (PMMA) were discovered, respectively, in 1880 and 1930. The resins have been used for the production of transparent plastic sheets, viz. Plexiglas or Perspex , used for the military aircraft cockpit canopies, gunner s turrets and the like [Riddle, 1954]. Acrylic elastomers (ACM or ANM) were developed by Rohm in 1901, and commercialized in 1948 as Hycar vulcanizable copolymers of ethyl acrylate, allyl maleated lactones, chloroethyl vinyl ether, butadiene, isoprene, acrylonitrile, etc. [Mast et al., 1944]. Since the 1950 s, a wide variety of acrylic compatibilizers and impact modifiers have been developed. 

The substrate must be clean and free from particulate matter. Adhesion to acrylic plastics is normally excellent. We have found that the combination of isopropanol and acetic acid will gently attack and swell a polymethylmethacrylate (PMMA) surface and is more aggressive as the molecular weight of the PMMA is decreased. Excellent adhesion to polycarbonate can be obtained by heating the polycarbonate for two hours at 125°C before the coating is applied. 

CF4, CF4 h O2 1. Enhancement of wettability of plastic surfaces Polyethylene (PE), polyoxymethylene (aeetal), polystyrene (PS), polypropylene (PP), polytetrafluoroethylene (PTFE), polymethylmethacrylate (PMMA), polyimide (PI)... 

Obtain DSC thermal curves of several semicrystaUine polymers such as polymethylmethacrylate (PMMA), polystyrene, polycarbonate, high-density polyethylene, low-density polyethylene and look for the glass transition in these polymers. The DSC run may need to be repeated twice with rapid cooling between runs. Many as received polymers will show a small peak on top of the glass transition on the first mn due to relaxation effects in the polymer. The second run should not show this peak , but only a step change in the baseline. Compare your values of Tg to literature values. Deviations may indicate the presence of plasticizers or other additives in the polymer. 

Ono [39] showed in 1986 that carbon powders coated with polymethylmethacrylate were directly moldable into sheets that had excellent thermal properties and could also be used as electric conductive plastics. 

Whereas polymethylacrylate (PMA) is within its main plasticization range at room temperature (Tg at 5 °C), polymethylmethacrylate (PMMA) is still in the vitreous state at this temperature (Tg at 105 °C). Because of the statistical copolymerization of MMA with MA, there a downward shift of the glass transition... 

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