2,3,5,6-tetramethyl-l, 4-phenylene

The polyamic acids were prepared from 3,3 ,4,4-benzophenone dianhydride (sublimed) and 2,3,5,6-tetramethyl-l,4-phenylene diamine in Cold Label N,N-dimethyl formamide (DMF). All chemicals were obtained from Aldrich. A solution of the anhydride was added over 30 minutes to a solution of the amine with stirring under N2 at room temperature at a net concentration of 15% solids. In general, a slight (1%) excess of the anhydride was needed to give maximum viscosity. 

The model polyimide chosen for this study was the polymer derived from 3,3 ,4,4-benzophenone tetracarboxylic dianhydride and 2,3,5,6-tetramethyl-l,4-phenylene... 

Poly(oxy-2,6-dimethyl-l,4-phenylene) (poly(phenylene oxide) PPO) is widely used as a high-performance engineering plastic, since the polymer has excellent chemical and physical properties, including a high Tg (ca. 210 °C) and mechanical toughness [16]. Initially, PPO was prepared from 2,6-dimethylphenol monomer using a copper/amine catalyst system [36]. By contrast the H RP-catalyzed polymerization of 2,6-dimethylphenol provided the polymer that consisted exclusively of oxy-l,4-phenylene units, although a small amount of Mannich-base and 3,5,3 5 -tetramethyl-4,4 -diphenoquinone units are invariably present in chemically prepared PPO. 

TMDA52,3,5,6-tetramethyl phenylene diamine 6FDA55,5"-(l,l,l-trifluoromethyl)ethylidene)bis-l,3 isobenzoftirandione PP05poly(2,6-dimethyl-l,4-phenylene oxide) temperature 25 °C for PTMSP and poly(4-methyl-l-pentyne) other polymers at 35 °C... 

Poly(2,6-dimethyl-l,4-phenylene oxide) (PPO) is most frequently synthesized by the oxidative polymerization of 2,6-dimethylphenol which should result in a polymer containing one phenyl and one phenolic chain end (PPO-OH) (see also Chapter 28 of Volume 5). However, in all cases, a disproportionation reaction occurs to form the side product 3,3, 5,5 -tetramethyl-4,4 -diphenylquinone, which reacts with PPO-OH according to equation (65) in Scheme 62 to yield a certain amount of PPO containing two phenol chain ends (PP0-20H). More recently, Heitz and co-workers and Nava and Percec have developed procedures to prepare PP0-20H according to equations (64) and (66) in Scheme 62. 

Figure 10 Correlation between polymer density and helium permeability P through polyethylene at 25 °C 1, poly(tetra-methyl-bis-L terephthalate) (1) 2, poly(tetraisopropyl-bis-A sulfone) (2) 3, poly(2,6-dimethyl-1,4-phenylene oxide) (3) 4, poly(tetramethylcyclobutanediol carbonate) (4) 5, poly(tetramethyl-bis-A carbonate) (5) 6, poly(tetramethyl-bis-L sulfone) (6) 7, poly(tetramethyl-bis-A terephthalate) (7) 8, poly(tetramethyl-bis-A sulfone) (8) 9, poly(bis-A carbonate) (9) 10, poly(bis-...

Poly (oxy adipoyloxy-2,6-dichloro-1,4-phenylene-isopropylidene-3,5-dichloro-l,4-phenylene) Poly(oxyadipoyloxy-3,3, 5,5 -tetramethyl-4,4 -biphenylylene)... 

Fig. 2. Reactivity of aromatic diisocyanates 0.02 M with 2-ethyihexanol 0.4 M and diethylene glycol adipate polyester in benzene at 28°C. (A) l-Chloro-2,4-phenylene diisocyanate. (B) m-Phenylene diisocyanate. (C) p-Phenylene diisocyanate. (D) 4,4 -Methylene bis(phenyl isocyanate). (E) 2,4-Tolylene diisocyanate. (F) Tolylene diisocyanate (60%, 2,4-isomer, 40% 2,6-isomer). (G) 2,6-Tolylene diisocyanate. (H) 3,3 -Dimethyl-4,4 -biphenylene diisocyanate (0.002 M) in 0.04 M 2-ethylhexanol. (I) 4,4 -Methylene bis(2-methylphenyl isocyanate). (J) 3,3 -Dimethoxy-4,4 -biphenylene diisocyanate. (K) 2,2,5,5 -Tetramethyl-4,4 -biphenylene diisocyanate. (L) 80% 2,4- and 20% 2,6-isomer of tolylene diisocyanate with diethylene glycol adipate polyester (hydroxyl No. 57, acid No. 1.6, and average molecular weight 1900). Reprinted from M. E. Bailey, V. Kirss, and R. G. Spaunburgh, Ind. Eng. Chem. 48, 794 (1956). (Copyright 1956 by the American Chemical Society. Reprinted by permission of the copyright owner.)...

Fig. 9.59 Plot of temperature of maximum spherulite growth rate, Tmax, against equilibrium melting temperature. I m, for indicated polymers. (1) isotactic poly(styrene) (a) (2) poly(tetramethyl-p-silphenylene siloxane) (b) (3) poly(cis-isoprene) (c) (4) poly(caproamide) (d,e) (5) poly(L-lactic acid) (f) (6) poly(phenylene sulfide) (g,h) (7) poly(R-epichlorohydrin), poly(S-epichlorohydrin), poly(I-RS-epichlorohydrin) (i) (8) poly(ethylene terephthalate) (j,k,l) (9) poly(aryl ether ether ketone) (m,n) (10) poly(ethylene-2,6-naphthalene dicarboxylate) (n) (11) poly(3-hydroxybutyrate) (o) (12) isotactic poly(methyl methacrylate) (q) (13) poly(dioxolane) (r) (14) New TPI poly(imide) (s) (15) poly(methylene oxide) (t) (16) poly(cis-butadiene) (u) (17) poly(propylene oxide) (v,w) (18) poly(imide) BPDA - - 134 APB (x) (19) poly(imide) BPDA - -C12 (x) (20) syndiotactic poly(propylene) (y) (21) poly(3-hydroxy valerate) (z) (22) poly(ethylene succinate) (aa) (23) poly(aryl ether ketone ketone) (bb) (24) poly(phenylene ether ether sulfide) (cc) (25) poly(tetramethylene isophtha-late) (dd) (26) poly(hexamethylene adipamide) (e,ee) (27) poly(tetrachloro-bis-phenol-A adipate) (fQ nylon 6-10 (ee).

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