Polymethyl methacrylate, 413 Table

Polymethyl Methacrylate. Table 4 shows the results obtained for three commercially available polyraethyl methacrylate samples. Again the molecular weight averages obtained with SEC/Viscometry are in good agreement with the nominal values and the K and o values are self-consistent and in excellent agreement with the literature values.(40)... 

Table 1. Propagation constants of polymethyl methacrylate ion-pairs in THF at —98 °C 43)...

Another differential reaction is copolymerization. An equi-molar mixture of styrene and methyl methacrylate gives copolymers of different composition depending on the initiator. The radical chains started by benzoyl peroxide are 51 % polystyrene, the cationic chains from stannic chloride or boron trifluoride etherate are 100% polystyrene, and the anionic chains from sodium or potassium are more than 99 % polymethyl methacrylate.444 The radicals attack either monomer indiscriminately, the carbanions prefer methyl methacrylate and the carbonium ions prefer styrene. As can be seen from the data of Table XIV, the reactivity of a radical varies considerably with its structure, and it is worth considering whether this variability would be enough to make a radical derived from sodium or potassium give 99 % polymethyl methacrylate.446 If so, the alkali metal intitiated polymerization would not need to be a carbanionic chain reaction. However, the polymer initiated by triphenylmethyl sodium is also about 99% polymethyl methacrylate, whereas tert-butyl peroxide and >-chlorobenzoyl peroxide give 49 to 51 % styrene in the initial polymer.445... 

In Table 3 results axe summarized which were obtained at three different temperatures for a solution of 2.5 g polymethyl methacrylate in 10 g vinyl acetate containing 50 mg benzoyl peroxide (203). 

Table 3. Grafting of vinyl acetate on polymethyl methacrylate...

This tertiary amine group terminated polymer can undergo transfer in the presence of a second monomer (25, 26), e.g. with acrylonitrile or methyl acrylate which show an exceptionally high transfer constant with such groups (see Table 2). By this method acrylonitrile blocks are bounded to polymethyl methacrylate sequences the overall composition of these block copolymers may be represented by... 

Table 4 shows the analyses of the spectra of a number of free radical polymethyl methacrylates prepared under conditions varying as indicated the spectra are interpreted in terms of the proportions of i, h, and s units. In Fig. 14, these results have been fitted to the probability curves by placing the s points on the curve and letting the other points fall where they may. 

Table 6. The Stereochemical Configuration of Free Radical Polymethyl Methacrylate as a Function of the Temperature of Polymerization...

TABLE 1. Storage modulus testiug of homopolymers aud a-acetoxyacrylate copolymers. Polymethyl methacrylate is provided as a reference. 

Reimers and Schork [144] have used polymethyl methacrylate as the costabilizer for methyl methacrylate miniemulsion polymerization. A portion of the results are shown in Table 10. In this case, the miniemulsion has a narrower particle size distribution than the equivalent macroemulsion. 

Table 10 Polymethyl methacrylate as costabilizer with methylmethacrylate monomer (from [144])...

X-ray and neutron diffraction measurements on polyion hydration give the number of water molecules involved per repeat group in the structures. About one water molecule per repeat group is the result for polymethyl methacrylate. The results of hydration for a variety of proteins are given in Table 2.31. 

For the remainder of this section, three examples illustrating the behavior predicted in Table 6.4 are discussed. Singer et al. (28) have extensively investigated field-induced alignment for the azo dye Disperse Red I in polymethyl methacrylate (PMMA). Using a dopant molecule number density of 2.74 X 10 /cm, they showed the reasonably linear behavior of Xxxx pohng field when the film was poled above its Tg and quenched in the... 

Swelling of polymethyl methacrylate latex particles with methyl methacrylate. Table IV lists the swelling ratios and interfacial tensions for the different-size polymethyl methacrylate latexes with added Aerosol MA and sodium dodecyl sulfate emulsifiers. Comparison of the data with the theoretical curves from Model I (Figure 2) defines an apparent interaction parameter of 0.45 and the semi-empirical equation ... 

It may be seen from Table IV that values of a found for solutions of polyvinyl acetate in toluene are systematically higher than for those for corresponding solutions of polymethyl methacrylate. This confirms the known fact that the polyvinyl chain has a greater mobility than the polymethacrylate chain. 

SMA copolymers and terpolymers have also been used for blending with PVC to improve the heat distortion temperature and processability of PVC. These blends also contain a rubbery component for impact modification that is usually a high rubber ABS or a polymethyl methacrylate grafted styrene-butadiene rubber (MBS). For improved weatherability, acrylic rubber modified PVC has been used for blending with SMA copolymers and terpolymers (Table 15.4). The market for SMA/PVC blends is still relatively low in volume with only a few applications such as in business machine housings as a low cost replacement for flame retarded ABS. 

Table 111. Cellular Adhesion from Blood of Normal and Decomplemented Animals Exposed to Nylon and Polymethyl Methacrylate...

The most common conhguration for performing on-chip detection has been the embedded hber type of device as listed in Table 1. A typical setup, shown in Fig. 1, includes a light source and fiber for delivery, exit fiber connected to a detection system, microfluidic channel, and liquid delivery components. The fibers are usually embedded in chip materials consisting of polydimethylsiloxane (PDMS), SU-8 epoxy, polymethyl methacrylate (PMMA), or glass [3]. 

The stoiometry described in Table 1 supports the estimate that about 15% of the polymethyl methacrylate is not hydroxyl modified. 

Because it is more corrosive than fresh water, salt water not only attacks metals but also degrades even the so-called inert polymers polyethylene, polypropylene, polystyrene, polymethyl methacrylate, etc. (26). Indeed, salt water is very corrosive to adhesive joints. For example, it was reported (27) that exposure to a 5% salt spray for three months had a more severe effect on aluminum joints (stressed DCB) than exposure to a semi-tropical environment for three years. In Table 1, McMillan (27) compares the severity of salt spray with a natural, semi-tropical environment and various in-service conditions. 

The Henry s law constant for a given polymer can be correlated with the e/ k factor (see Table 5-4). Such correlations are shown in Figs. 5-12 and 5-13. A more generalized correlation is shown in Fig. 5-14, where the Henry s law constant is correlated with the gas critical temperature for thermally softened polymers (polyisobutylene, polystyrene, and polymethyl methacrylate). Figure 5-14 offers the possibility of estimating a Henry s law constant for a polymer for which there are no data. 

It is seen in Table 11.1 that commonly used polymers (e.g., polyolefins and their copolymers, polymethyl methacrylate) and polytetrafluoroethylene have very poor resistance to gamma irradiation and should not be used in applications in which exposure to this type of irradiation occurs. 

Acid-base parameters of some materials are shown in Table 2.5. The surface of polymethyl methacrylate (PMMA) is alkaline, the surface of Si02 is acidic, and the surface of a-Fe203 is alkaline. 

Prehydrolyzed bagasse led to composites of distinctly low polymer load 2.0%, when Using sodium bisulfite-soda lime glass system as initiator for grafting polymethyl methacrylate (sample 16, Table... 

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