Polymethylmethacrylate composites

Shamrakov D., Reisfeld R. Superradiant laser operation of red Perylimide Dye doped silica-polymethylmethacrylate composite. Chem. Phys. Lett. 1993 213 47-54 Shamrakov D., Reisfeld R. Super radiant film laser operation of perylimide dyes doped silica-polymethylmethacrylate composite. J. Opt. Mater. 1994 4 103-106 Sorek Y., Reisfeld R., Finkelstein I., Ruschin R. Sol-gel glass wave guides prepared at low temperature. Appl. Phys. Lett. 1993 63 3256-3258... 

Heikkila JT, Aho AJ, Kangasniemi I, Yli-Urpo A. Polymethylmethacrylate composites disturbed bone formation at the surface of bioactive glass and hydroxyapatite. Biomaterials 1996 17 1755-60. 

The soapless seeded emulsion copolymerization method was used for producing uniform microspheres prepared by the copolymerization of styrene with polar, functional monomers [115-117]. In this series, polysty-rene-polymethacrylic acid (PS/PMAAc), poly sty rene-polymethylmethacrylate-polymethacrylic acid (PS/ PMMA/PMAAc), polystyrene-polyhydroxyethylmeth-acrylate (PS/PHEMA), and polystyrene-polyacrylic acid (PS/PAAc) uniform copolymer microspheres were synthesized by applying a multistage soapless emulsion polymerization process. The composition and the average size of the uniform copolymer latices prepared by multistage soapless emulsion copolymerization are given in Table 11. 

In particular, blends of PVDF with a series of different polymers (polymethylmethacrylate [100-102], polyethylmethacrylate [101], polyvinyl acetate [101]), for suitable compositions, if quenched from the melt and then annealed above the glass transition temperature, yield the piezoelectric [3 form, rather than the normally obtained a form. The change in the location of the glass transition temperature due to the blending, which would produce changes in the nucleation rates, has been suggested as responsible for this behavior. A second factor which was identified as controlling this behavior is the increase of local /rans-planar conformations in the mixed amorphous phase, due to specific interactions between the polymers [102]. 

Polymethylmethacrylate can be modified with monoethanolamine to form a water-soluble polymer (Deman). Deman is used as a cement additive to increase the strength in amounts smaller than 0.5% of the total weight of the composition [1595]. The produced plugging stone has improved strength characteristics within a temperature range from —30° to -1-300° C. 

Preparation of nanoparticles can be by a variety of different ways. The most important and frequently used is emulsion polymerization others include interfacial polymerization, solvent evaporation, and desolvation of natural proteins. The materials used to prepare nanoparticles are also numerous, but most commonly they are polymers such as poly-alklcyanoacrylate, polymethylmethacrylate, poly-butylcyanoacrylate, or are albumin or gelatin. Distribution patterns of the particles in the body can vary depending on their size, composition, and surface charge [83-85]. In particular, nanoparticles of polycyanoacrylate have been found to accumulate in certain tumors [86,87]. 

As you can see, bone is a very complex composite material and, as snch, is difficult to artificially replicate. Nonetheless, there are a nnmber of materials of all types that are being nsed as bone replacements. Polymethylmethacrylate (PMMA), titaninm, graphite/polyethyletherketone (PEEK) composites, and tricalcinm phosphate, among... 

Polymer nanotubes composites are now extensively studied. Indeed, one may associate the properties of the polymer with those of nanotubes. This is the case of the mechanical reinforcement of standard polymer for example, but also one can take advantage of the specific electronic properties of the nanotubes. Therefore, we prepared composites with either saturated polymers like polymethylmethacrylate and MWNTs [27]. The electrical conductivity of these compounds as a function of the nanotube content exhibits for example a very low percolation threshold, (a few % in mass) and therefore they can be used as conducting and transparent layers in electronic devices such as Light Emitting Diodes (LEDs). Another type of composite that we have studied is based on the use of a conjugated polymer, polyphenylene-vinylene (PPV) known for its photoluminescence properties and SWNTs. We prepared this composite by mixing SWNTs to the precursor polymer of PPV. The conversion into PPV was subsequently performed by a thermal treatment at 300°C under dynamical vacuum [28],... 

Surface fluorination of several polymers other than polyethylene has been attempted to show the effectiveness of this technique in generating perfluorinated surfaces. Results of formamide contact angle experiments are summarized in Table (3). It appears from these results that under the conditions studied, polypropylene and nylon 6,6 can be perfluorinated but polymethylmethacrylate does not perfluorinate in the time scale shown. The C, XPS spectra and the respective chemical compositions are shown in Figure (7) and Table (3). Even though PMMA shows high... 

Photopolymerizable compositions have found their use in the production of thick (5-100 pm) relief images, especially in the field of printed plates and micromachinery. The compositions contain a monomer, matrix polymer (binder), and photoinitiator. The branched monomers are used most frequently. Many photosensitive compounds generating radical and ion centers upon UV irradiation are used as a part of the compositions. Polymethylmethacrylate and its derivatives are very often used as polymer binders. 

The effect of filler density on the density of filled product can be closely approximated by the additivity rule. If a more precise method of density estimation is required or filler/matrix mixtures are far Ifom being perfect, several corrections are necessaiy. System density becomes nonlinear close to the critical volume concentration (CVC). The critical volume concentration determines the amount of conductive filler which rapidly increases the conductivity of the composite. Figure 5.1 shows that at, or close to the critical volume concentration, density decreases. This density difference can be detected either after the CVC (polyethylene), before (polystyrene) or the two depressions are observed - one before and one after the CVC (polymethylmethacrylate) is reached. This density depression is due to filler-matrix interaction. 

Cement is a binder that sets and hardens by itself or binds other materials together. The most widely known application of cements is in construction a second one is the area of bone cements. Cements used in construction are characterized as hydraulic or nonhydraulic and mostly for the production of mortars and concrete. Hydraulic cements set and harden after combining with water. Most construction cements are hydraulic and based on Portland cement, which consists of calcium silicates (at least 2/3 by weight). Nonhydraulic cements include the use of nonhydraulic materials such as lime and gypsum plasters. Bone cements and bone cement composites refer to compounds that have a polymer matrix with a dispersed phase of particles. For instance, polymethylmethacrylate (PMMA) is reinforced with barium sulphate crystals (for radio-opacity) or with hydroxyapatite... 

Analysis of the infrared spectra requires accounting for thin film interference effects, which, upon shock compression, change the composite reflectivity. To analyze the thin film interference effects, the infrared complex refractive index spectra for ambient samples of PVN, and the inert polymethylmethacrylate (PMMA), were determined as described in the section above. The only modification to the description above is the inclusion here of the dispersive rarefaction wave that releases the pressure [102]. 

Wang, Y Shi, H. Xia, T.D. Zhang, T. Feng, H.X. Fabrication and performances of microencapsnlated paraffin composites with polymethylmethacrylate shell based on nltraviolet irradiation-initiated. Mater ChemPhys 135 (2012) 181-187. 

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