Poly methacrylonitrile

8) have been extensively studied. In contrast with the analogous esters 8-10 (Section 5.2.2.1.2), combination is by far the dominant process (Table 5.4). 

Serelis and Solomon found that primary radical termination of oligo(MAN) radicals (16) with 15 also gives predominantly combination. The ratio was found to have little, if any, dependence on the oligomer chain length (n 4). As with PMMA, disproportionation involves preferential abstraction of a methyl 

Cyanoisopropyl radicals (15) undergo unsymmetrical C-N coupling in preference to C-C coupling. The preferential formation of the ketenimine is a reflection of the importance of polar and steric influences. However, the ketenimine is itself thermally unstable and a source of 15, thus the predominant isolated product is often from C-C coupling. 

A ketenimine (21) is the major product from the reaction of the dimeric MAN radical 18 with cyanoisopropyl radicals (15). Only one of the two possible kctcnimincs was observed a result which is attributed to the thermal lability of ketenimine 19. If this explanation is correct then, although C-N coupling may 

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SCHEME 15. Thermolysis of poly(methacrylonitrile peroxide) by homolytic scission of the per-oxy links... 

Nuclear spin relaxation, poly(methacrylonitrile peroxide), 709... 

Polymer immobilization. Mo-peroxide, 427 Polymerization agents, 621, 622 peroxide value, 661, 662 peroxycarboxyUc acids, 698 radical polymerization, 697, 707 styrene, 697, 720 sulfonyl peroxides, 1005 thermochemistry, 155 Polymers aging, 685 autoxidation, 623 hydroperoxide determination, 685 Poly(methacrylonitrile peroxide)... 

Figure 2 shows survey Raman spectra of the hcmopolymers, poly(methyl methacrylate)(PMMA.), poly(3-oximino-2-hutannone methacrylate)(pom), and poly(methacrylonitrile)(PMAN), and one terpolymer(P(M-0M-CN)) with a S/N ratio of about 10 1. Each of the polymers has a band specific to that polymer 8l2 dcm-1 (vg (C-O-C) for IMMA), 1622 hem" (Vg(C=N) for POM), and 2237 dcm l(vg(CHN) for PMAN). Additionally, there is an asymmetric C-H bending mode at 1 53 Acm l, common to all three homopolymers, which serves as an internal standard. These bands are indicated by arrows in Figure 2. A broad fluorescence background is evident, but it can be reduced to acceptable levels by exposure to high laser power for 10-30 minutes, depending on the sample. Residual background fluorescence may be due to the oximino chromophore itself. Figure 3 depicts an example of actual data for a 75 15 10 terpolymer with a S/N ratio of about 50 1.

C02CH2CH(CH3)2 - poly(Isobutyl methacrylate) (PIBM) C02C(CH3)3- poly(tert-butyl methacrylate) (PTBM) CO2CH2CCI3- poly(trichloroethyl methacrylate) (PTCEM) CO2CH2CF2 poly(trifluoroethyl methacrylate) (PTFEM) C02CH(CF3)2 poly(hexafluoroisopropyl methacrylate)(PHFIM) CN - poly(methacrylonitrile)(PMCN)... 

The resorcinol-formaldehyde polymers have been used to prepare highly porous carbon materials, by controlled pyrolysis in an inert atmosphere [144,154], The microstructure of the carbon is an exact copy of the porous polymer precursor. Poly(methacrylonitrile) (PM AN) PolyHIPE polymers have also been used for this purpose. These monolithic, highly porous carbons are potentially useful in electrochemical applications, particularly re-chargeable batteries and super-capacitors. The RF materials, with their very high surface areas, are particularly attractive for the latter systems. 

C6Hj-N = N-C(C6H5)2(OCOCH3) b By membrane osmometry, PM AN = poly(methacrylonitrile) c By GPC, calibrated with polystyrene standards d Grafting efficiency (see Sect. 3.2.7)... 

Fig. 10. Dependence of weight average molecular mass of poly (methacrylonitrile) on conversion. Monomer concentration 1 = 1,2 2 = 2,1 mol/1 [Et3P] = 10 mmol/1...

This method of estimation of 5 was applied to polymethacrylonitrile (PMAN), polymeth-acrylic acid (PMA) and poly(methacrylonitrile-co-methacrylic acid) (MAN/MAA copolymer)... 

MOT Motowoka, M., Fujita, H., and Norisuye, T., Stiff chain behavior of poly(tereph-thaloyl-P an5 -2,5-dimethylpiperazine) in dilute solution, Polym. J., 10, 331, 1978. 1978RED Reddy, G.V. and Santappa, M., Dilute solution properties of poly(methacrylonitrile) and copolymers of methacrylonitrile with methacrylates, Indian J. Chem., 16A, 99,... 

TYPES OF POLYMERIZATION Free-radical or ionic polymerization of methacrylonitrile (2-cyanopropylene) in bulk, emulsion, or solution group-transfer polymerization also has been used. Ionic polymerization in inert solvents can produce either amorphous poly(methacrylonitrile) (by use of anionic catalysts such as n-butyllithium) or primarily isotactic poly(methacrylonitrile) (by use of coordination catalysts such as ethylberyllium or diethylmagnesium). 

Tlie simplest model for the polymerization of MAN is that of the decomposition of AIBN. The cyanoisopropyl radical mimicks the action of a propagating poly(methacrylonitrile) radical. 

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