Preparation and Polymerization Behavior of 2,4-Dicyanostyrene and 2,4,6-Tricyanostyrene

distribution will be considered. In conclusion, we have demonstrated the pronounced effect of laser repetition rate on the molecular weight distribution of photopolymerized methyl methacrylate. The narrow peaks found in the GPC chromatogram of poly(methy1 methacrylate) generated by firing the laser at a repetition rate of 40 Hz (25 ms between successive pulses) have been initially described by a simple kinetic model based upon a series of Poisson distribution functions. Complete details of the computer simulation of the molecular weight distributions as a function of pulsing frequency as well as several refinements to our current approach, will be published in a full paper. This paper serves to provide a basis for describing the crucial effect of laser parameters on the polymerization of monofunctional monomers. Extension of this work to encompass multifunctional monomers is in progress. Acknowledgment. This research is supported by National Science Foundation Grant DMR 85-14424 (Polymers Program). Acknowledgement is also made to NSF for assistance in purchasing the laser system utilized in the course of this investigation (Grant CHE-8411829-Chemical Instrumentation Program). References and Notes Registry No. PMMA, 9011-14-7. (1) Decker, C. ABSTRACT: 2,4-Dicyanostyrene (DCS) was successfully prepared in 18% yield via a series of six reactions and 2,4,6-tricyanostyrene (TCS) was barely in 0.15% yield via five reaction steps. It was found that DCS and TCS are polymerizable with radical and anionic initiators. DCS and TCS are copolymerizable in a random and an alternating fashion, respectively, with styrene (St) in the presence of 2,2'-azobis(isobutyronitrile) (AIBN) in acetonitrile to afford the monomer reactivity ratios rl(DCS) = 1.85 f 0.03 and rz(St) = 0.08 f 0.03 for the DCS-St system at 60 O C and r,(TCS) = 0.02 i 0.02 and rz(St) = 0.04 i 0.01 for the TCS-St system a t 60 "C. By using these values, the Alfrey-Price's Q and e values were determined to be Q = 4.10 and e = +0.58 for DCS and Q = 2.83 and e = +1.86 for TCS. When DCS or TCS was mixed with p-(dimethy1amino)styrene (DMASt), the former system was colored pale yellow and did not undergo further reaction, while the latter one was colored red and underwent spontaneous reaction to give polymeric product containing homopolymers of TCS and DMASt, suggesting that anionic polymerization of TCS and cationic one of DMASt occur at the same time. Introduction Only a few compounds have been reported of the electron-accepting group substituted styrenes carrying more than two strongly electron-withdrawing groups on the benzene nucleus, such as 2,4,6-trinitrostyrene (TNS),1-3 2,4,6-tris(trifluoromethyl)styrene (TFS),4 and 2,5-, 3,5-, and 3,4-bis(trifluoromethyl)styrenes.6 Although the cyano (up = 0.674)6 group is strongly electron withdrawing and its character is just intermediate between that of nitro (up = 0.778)6 and trifluoromethyl (ap = O l~3 2 )~ groups, polycyano-substituted styrenes have not yet been found in any literature, but 0-, m-, and p-monocyanostyrenes7-9 wer

P.G.; “Scaling Concepts in Polymer

2633 5.3 X cm2 s-l within an experimental error of 10% from the linear plot of the relaxation time 7, of the decay profile of the diffraction intensity vs. d2, the square of the grating spacing. The value is larger than Dslow by a factor of about 5, even ABSTRACT Time-average and time-dependent intensity of light scattered by linear polyethylene (LPE), Dutch State Mines sample L30-4-6, in a good organic solvent, 1,2,4-trichlorobenzene at 135 "C, was measured as a function of polymer concentration at scattering angles between 35 and 145O. Molecular properties determined were the z-average radius of gyration, = 50 nm, the z-average hydrodynamic radius, (Rh-');l = 27 nm, the weight-average molecular weight, (M)w = 570, the weight distribution, Fw(M), and the second virial coefficient, Az = 1.5 X lom3 g" mL mol. The main purpose of this article was to determine F J M ) for a LPE based on (M)w, (R:),, A2, and the characteristic line width distribution G(r) computed from an inverse Laplace transform of the measured single-clipped time correlation function, Gk@)( 7). We have demonstrated thh nonintrusive technique to be particularly useful in obtaining an approximate Fw(M) for polydisperse synthetic high polymers which are difficult to characterize by more established analytical techniques such as gel permeation chromatography (GPC)