PMMA, thermoplastic matrix

A series of works has been done in this field of growing interest for the purposes of improving the dispersibility of nanoparticles in solvents and their compatibility in polymers [25]. Mostly, the graft polymerization is conducted via two routes (1) monomers are polymerized from active compounds (initiators or comonomers). PMMA is a commonly used thermoplastic matrix for fibers, sheets, and particles. There have been several studies on PMMA-fiber composites prepared by in situ polymerization [26], solution mixing [27], or melt blending [28]. The last one is already an industrial process for fabricating carbon fiber-reinforced thermoplastic composites. 

After isolation of the final composite, it was concluded that CNTs were homogeneously distributed in the thermoplastic matrix [poly(methyl methacrylate) (PMMA)]. 

Blends of ASA with many of the common thermoplastic materials are state of the art. The properties of the finished products depend to a large extent on the polymer compatibility often induced by the use of reactive polymers. Only a few of these blends have reached a significant commercial status. The largest blend products in this area are ASA-PC blends followed by ASA-PBT and ASA-PC-PMMA blends. Combinations of ASA with high-Tg matrix polymers are also frequently found in commercial products. 

The fibres are surface treated during manufacture to prepare adhesion with the polymer matrix, whether thermosetting (epoxy, polyester, phenoUc and polyimide resins) or thermoplastic (polypropylene. Nylon 6.6, PMMA, PEEK). The fibre surface is roughened by chemical etching and then coated with an appropriate size to aid bonding to the specified matrix. Whereas composite tensile strength is primarily a function of fibre... 

All TP or TS matrix property can be improved or changed to meet varying requirements by using reinforcements. Typical thermoplastics used include TP polyesters, polyethylenes (PEs), nylons (polyamides/ PAs), polycarbonates (PCs), TP polyurethanes (PURs), acrylics (PMMAs), acetals (polyoxymethylenes/POMs), polypropylenes (PPs), acrylonitrile butadienes (ABSs), and fluorinated ethylene propylenes (FEPs). The thermoset plastics include TS polyesters (unsaturated polyesters), epoxies (EPs), TS polyurethanes (PURs), diallyl phthalates (DAPs), phenolics (phenol formaldehydes/PFs), silicones (Sis), and melamine formaldehydes (MFs). RTSs predominate for the high performance applications with RTFs fabricating more products. The RTPs continue to expand in the electronic, automotive, aircraft, underground pipe, appliance, camera, and many other products. 

These foams can be defined as composites consisting of hollow microspheres and a polymeric matrix. This one is made of a thermosetting (PU, PIR, PF, EP, silicone or unsaturated polyester) or of a thermoplastic (PE, PP, PVC, PS, polyimide) [56]. The microspheres can be made of silica, glass, carbon, ceramics or polymers such as PS, PE, PP, polyamide (PA), polymethyl methacrylate (PMMA), divinyl benzene (DVB)-maleic anhydride, and so on [56-58]. The diameter of the tiny hollow spheres is 300 mm or less [35]. They contain an inert gas such as nitrogen or a CFC. The properties of these syntactic foams depend on matrix type, microsphere type (and the contained gas), ratio matrix to microspheres, curing process, production technology. Syntactic foams can be made in combination with the conventional ones. Such a complex composite can be formnlated into a mouldable mass then shaped or pressed into cavities. 

PMMA is a thermoplastic polymer commonly employed as the main component of positive resists for electron and UV photolithography [37, 38], as well as an imprintable material for hot-embossing soft lithography [39]. Because of its excellent transparency in the visible spectrum, PMMA is widely used in optical applications, especially as a matrix for nonlinear optical composite materials [40, 41]. The process of thermoforming PMMA sheets has been used to produce a variety of dental pros-theses that include splints, stents, and bases for occlusal rims. 

For bulk materials, Jin et al fabricated poly (methylmethacrylate) (PMMA)/MWNT nanocomposites by melt mixing. MWNTs were well dispersed in the matrix [90]. Melt compounding is also widely used for the fabrication of composite fibers. Sandler et al mixed polyamide-12 pellets and CNTs in a twin-screw micro-extruder and then the extrudate was chopped and fed into a capillary rheometer with 1 mm die. The CNTs in the spun fibers were uniformly dispersed [91]. Not only can thermoplastic polymers be melt-compounded, polyimide, a thermoset plastic, can be also prepared by mixing the imide oligomer at 320 °C on a steel plate and then cured at 370°C. It was found that the dispersion of CNTs in... 

Thermoplastics used to blend with NR include PS, " polyamide 6, ethylene-vinyl acetate (EVA) copolymer, poly(methyl methacrylate) (PMMA), polypropylene (PP), low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE) " and high-density polyethylene (HDPE). To improve the properties of TPNR, modified NR is also used. ENR is the most frequently used modified NR. TPNR blends are prepared by blending NR and thermoplastics in various proportions. The role of rubber is to improve the impact strength and ductility of the plastic. Depending on the ratio, materials with a wide range of properties are obtained. The stiffness of the rubber is increased with the incorporation of plastic into the rubber matrix. The mechanical properties of TPNR again depend on the proportions of the rubber and thermoplastic components. The elastic properties of TPNR are considerably... 

Polymer blends are physical mixtures of polymers and provide a means of combining the useful properties of the constituent components to achieve an economic or property advantage. There are a number of commercial thermoplastic blends such as PPO/PS, ABS/PC, PVC/PMMA, and so forth currently in use [28], as summarized in Table 1.7. In polymer blends, the individual polymers are chemically different and do not form covalent bonds as in copolymers. The blends are often characterized by their phase behavior as being either miscible or immiscible. Certain blends are completely miscible and form a single phase, whereas others form domains rich in one polymer dispersed within the matrix of the second polymeric component. The degree of thermodynamic compatibility... 

In order to develop composites with better mechanical properties and environmental performance, it becomes necessary to increase the hydrophobicity of the biofibers and to improve the interface between matrix and biofibers. Graft copolymerization of biofibers is one of the best methods to attain these improvements. As of now, only few studies have reported the use of biofiber graft copolymers as reinforcing material in the preparation of composites [33], Mechanical properties of thermoplastic composites reinforced with acrylate-gro/led henequen cellulose fibers were studied. It has been found that best results could be obtained with poly(methyl methacrylate) (PMMA)-grafted cellulose fibers because of better fiber-matrix adhesion. The modulus of poly(vinyl chloride) (PVC) composites is increased when grafted or ungrafted cellulose are used as reinforcement but the composites with... 

The increase of stress at break in thermoplastic-based nanocomposites is usually related to the nature of the interactions between the matrix and the filler. Table 5.1 shows the tensile stress values for different matrix day nanocomposites. Nanocomposites such as exfoliated nylon 6-based nanocomposites [78] or intercalated PMMA-based nanocomposites [80] exhibit an increase in the stress at break. This increase is usually due to the polar (PMMA) and even ionic interactions (nylon 6 grafted onto the layers) between the polymer and silicate layers. In polypropylene (PP) and PS nanocomposites, the interactions between polymer matrix and clay interface are weak, so no enhancements in tensile stress were observed. 

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