Polymethyl-methacrylate polymer surface

Uses. Production of polymethyl methacrylate polymers for use in acrylic sheet and acrylic molding, extrusion powder, acrylic surface coatings, printing inks, and adhesives used in surgery and dentistry... 

The main experimental techniques used to study the failure processes at the scale of a chain have involved the use of deuterated polymers, particularly copolymers, at the interface and the measurement of the amounts of the deuterated copolymers at each of the fracture surfaces. The presence and quantity of the deuterated copolymer has typically been measured using forward recoil ion scattering (FRES) or secondary ion mass spectroscopy (SIMS). The technique was originally used in a study of the effects of placing polystyrene-polymethyl methacrylate (PS-PMMA) block copolymers of total molecular weight of 200,000 Da at an interface between polyphenylene ether (PPE or PPO) and PMMA copolymers [1]. The PS block is miscible in the PPE. The use of copolymers where just the PS block was deuterated and copolymers where just the PMMA block was deuterated showed that, when the interface was fractured, the copolymer molecules all broke close to their junction points The basic idea of this technique is shown in Fig, I. 

Liu and Rauch (2003) of Motorola investigated oligonucleotide probe attachment onto polystyrene (PS), polycarbonate (PC), polymethyl methacrylate (PMMA), and polypropylene (PP) plastic surfaces. They utilized three different immobilization processes SurModics surface modification solution (that allows attachment of adsorbed reactive groups to a surface by photoactivation of polymers at 254 nm). Pierce Reactive-Bind coating solution, and CTAB (cetyltrimethylammonium bromide, a cationic detergent). Not surprisingly, the microarray performances on these plastics varied. 

Figure 1 contains micrographs of polymethyl methacrylate (PMMA), polycarbonate (PC) and polytetrafluoroethylene (PTFE) surfaces which have undergone erosive wear by the impingement of glass beads. With all three polymers loss from the surface occurs by flake formation as indicated in each of the micrographs. 

Microfluidic Boards Microfluidic board interconnection technologies seek to mimic the electronic printed circuit board for ease of use, reliability, and versatility. In microfluidic board technologies, the substrate contains the passive microfluidic channels and reservoirs, with active components (e.g., sensors, valves) mounted on top (e.g.. Ref. [2]) (see Fig. 1) similarly to electronic components mounted on a printed circuit board (PCB) or multichip modules (MCM) in surface-mount technologies (SMT). Electronic coimections between components are provided on top of the board, while fluidic interconnection is usually provided in the board material itself. Microfluidic circuit boards can be made from a variety of materials, including silicon, glass, and polymers, e.g., polydimethylsiloxane (PDMS), epoxy, or polymethyl methacrylate (PMMA). Microfluidic boards can be as simple... 

Of course, it is impossible to find particles with zero adhesion to confirm the theoretical argument that spheres should form a face-centered cubic structure above 0.49 volume fraction. However, certain types of polymer latex can be made to approximate to the theoretical nonadhesion conditions above. Polymethyl methacrylate particles were polymerized in a dispersion and polymer molecules were grafted to the surface to provide a steep repulsive force on close approach. The solvent was chosen to reduce the van der Waals force to a low level, by matching the refractive index to the spheres, obtaining an almost transparent suspension from the milky preparation. 

A factor that has been only rarely considered, but was pointed out by Vilanove et al. to be of importance, is the microstructure of the polymer stereochemistry. This is particularly relevant to methacrylates since their tacticity is determined by the synthetic method used. Isotactic polymethyl methacrylate displays expanded liquid isotherm behaviour whereas the syndiotactic polymer has an isotherm of the condensed liquid type. Given that this difference in behaviour was first remarked on some 30 years ago, the lack of appreciation of the importance of polymer stereochemistry in determining surface layer behaviour is surprising. Values of the exponent v at 25 "C obtained from the isotherms for the two stereoisomers of polymethyl methacrylate are 0.53 for the syndiotactic polymer and 0.78 for the isotactic polymer (Henderson et al. 1991). An additional factor here is that the relative molecular mass distribution for the isotactic poljmier is... 

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