Copolymers reactions

The transition temperatures that are combined in Figure 2 show the disappearance of crystallinity in the copolymers as the Ter and Tm flow together moving away from either homopolymer. This reflects the random distribution of monomer units in these copolymers. If the copolymer reactions had given homopolymer mixtures, there would be two separate crystalline melting temperatures. In addition, the 13C NMR indicates that the copolymer products contain a random distribution of C5 and C8 units and that the resulting double bonds are cis from the C8 monomer and largely trans from the C5 monomer (52). 

The synthesis of special initiators is another route to block copolymers. Reaction of XXXVI with an HO-terminated polyester or polyether yields a polymeric azonitrile, which initiates polymerization of a monomer such as styrene [Laverty and Gardland, 1977 Walz and Heitz, 1978],... 

Three unique di-diene have been utilized by Meek (9, 10) in the preparation of Diels-Alder copolymers. Reaction of 1,8-diphenyl-octatetraene with ftts-maleimides in refluxing chloroform for several days affords high yields of polymers with softening temperatures well over 300°, but low intrinsic viscosities. The copolymerization of 1,5-di(9-anthryl)-l,4-pentadiene-3-one and anthralazine with fo s-maleimides employs the diene nature of anthracene to obtain polymers with... 

Photochromic [1,2-b] naphthopyran derivatives, (IV), prepared by Hughes [4] exhibited absorption in the 400-550 nm (brown) range and were used in graft copolymer reactions. 

Isomerization from the secondary to the more stable tertiary carbonium ion precedes reaction with the next molecule of monomer. A 1,3 polymerization has therefore occurred. Similarly, 4-methyl-l-pentene gives a 1,4 polymer (probably involving two successive 1,2 hydride shifts) that has a structure corresponding to an ethylene-isobutylene copolymer (Reaction 25). 

The composition of the PAA-g-PS graft copolymer reaction product and its purification, especially as far as the removal of unreacted PS-MA macromonomer by silica column chromatography is concerned, and the successful selective cleavage of the ferf-butyl ester under acidic conditions to render the graft copolyelectrolyte PAA-g-PS were analyzed by XH NMR spectroscopy and SEC. Figure 8a shows the SEC curves of the polystyrene macromonomer (PS-MA), the crude poly (ferf-butyl acrylate-gra/f-styrene) (PTBA-g-PS) and the PTBA-g-PS the polymethylacrylate (PMA) originates from esterification of the poly (acrylic acid) (PAA) obtained after complete saponification of the graft copolymer and represents the backbone. The XH NMR spectra of PSMA, PTBA-g-PS and of the final reaction product PAA-g-PS are shown in Fig. 8b. 

Fig. 25. GPC chromatograms of a pMMA macroinitiator and a pMMA b-p4VP copolymer. Reaction conditions 40°C [4VP]0=4.62M [4VP]0/[pMMA-Cl]o=710 [pMMA-Cll]0/[Cu-Cl]0/[Me6TREN]o=l/2/2. Reprinted with permission from [198], Copyright (1999) American Chemical Society.

Copolymer Reactions. Rearrangement Reactions. Two poly(DHA-co-4VP) materials with 10-15 mole % DHA were thermolyzed in refluxing DMF (see Reaction 1). A strong nitrogen sparge was used to help remove the tertiary amine. The isolated poly(4-vinylpyridine-co-isopropenyl isocyanate) materials were insoluble in ether but soluble in chloroform, they had a strong band in the IR spectra at 2260 cm"1 and a weak band at 1710 cm"1, and they consisted of 1.5-2.0 wt % NCO. A sample of the thermolysis solution had a shelf life, i.e. lack of gelation, of about five days. 

Melt blending of PA-6 (or 66) with such an anhydride functionalized polypropylene causes a fast graft copolymer reaction between the polyamide and PP at the interface, which subsequently compatibilizes the blend. Some commercial polyamide/polypropylene blends may utilize such types of reactive compatibilization techniques. Properties of commercial PA/PP blends, both unfilled and glass filled grades, are shown in Tables 15.18 and 15.19. Typically, these blends... 

A weighable 10-mL Kel-F or FEP [Zeus] (fluoroethylene propylene copolymer) reaction vessel is best suited for this reaction. The compound HOTeFj is condensed onto XeF (3 g, 17.7 mmol) in about 3-g (12.5-mmol) portions, and the reaction mixture is warmed to a uniform melt. Subsequently, the HF that has formed and the unreacted HOTeF are pumped off at 0° and discarded. Alternatively, the HOTeFj can be freed of HF by trapping at -78° and reused. The above procedure must be repeated about six times, corresponding to a molar excess of HOTeFs of approximately 100%, to shift the equilibrium completely to formation of the product. This displacement is best monitored by weighing until constancy is reached. Yield 10.6 g (96%). 

OTM-containing polymers were constructed from 21 and 22 by reaction with an excess of a preformed 1/1 styrene/maleic anhydride copolymer. Reaction of ca. 5 mole percent 21 with the preformed polymer resulted in chemical incorporation of 3.0 mole percent of the substituted organometallic (Scheme XIV x=3.0). A similar reaction of the preformed polymer with 1.0 mole percent 22 gave a material which contained 0.7 mole percent cluster (Scheme XIV x=0.7). 

Entrapment in polyacrylamide gel over a platinum grid matrix Glutaraldehyde-mediated reaction with a nylon-polyethyleneimine copolymer Reaction with macroporous aminated silo chrome coated with an acrolein-vinylpyridine copolymer Adsorption onto tannin coupled to amino hex y 1-cellulo se Entrapment in cellulose fibres Carbodi-imide-mediated reaction with chitosan... 

Carbodi-imide-mediated reaction with carboxyhexyl-agarose Reaction with nylon imidate Adsorption onto nylon activated with triethyloxonium tetrafluoroborate glutaraldehyde cross-linking onto a nylon-polyethylene-imine copolymer Reaction with nylon imidate... 

Physical blends of bisphenol-A polycarbonate (PC) and a poly-arylate (PAr) exhibit by thermal analysis two amorphous phases a pure PC phase and a PAr-rIch miscible mixed phase. On controlled thermal treatment, transreaction between PC and PAr takes place mainly in the mixed phase, producing a new copolymer. Reaction progression from block to random copolymers has been traced by DSC, 13c NMR and CPC. The final product of transreaction is an amorphous copolymer showing a single T depending on the original binary composition. ... 

With Q-e values (20), the reactivity ratios of comonomers, rj and r, can be estimated using Equations 2 and 3. Monomer reactivity ratios can also be determined empirically by carrying out a series of copolymerizations and determining the polymer composition at low conversions. (20b) The reactivity ratios can be used to predict the nature of the copolymer type from a polymerization. For example, when the product of q and r has a value of zero, an alternating copolymer is likely to result from the copolymerization. On the other hand, when the product is near the value of one, the copolymer is likely to be a random copolymer. In a copolymerization process, if one of the comonomers does not homopolymerize, such as in the copolymerization of styrene (rj=0.019) and maleic anhydride (rj=0.0) at 50 °C (20,21), the polymer produced would be an alternating copolymer (Reaction 4). 

Using the more successful arm-first approach, in-chain functionalized stars were prepared. 2,3-Dicarbomethoxynor-bomadiene was polymerized with the same catalytic systems followed by the addition of the difunctional monomer, leading to the desired functionalized star polymers. SEC revealed the presence of 10-20% unreacted homopolymers. Using the same procedure, star-block copolymers can also be prepared. 2,3-Dicarbomethoxynorbomadiene was initially polymerized followed by the addition of norbomene for the synthesis of the living diblock copolymers. Reaction of these living diblocks with the difiinctional monomer afforded the star-block copolymers with complete consumption of the living arms (Scheme 56). 

Adipic acid-diethylenetriamine copolymer, reaction product with epichlorohydrin. Wet strength resin (30)... 

Compatibilization by a Redistribution Reaction to Produce Block and Random Copolymer Reaction Type 1... 

Compatibilization by Ionic Interaction to Form Copolymer Reaction Type 5... 

TABLE 12. Synthesis of random and block copolymers. Reaction conditions Solvent CH2CI2, 5-40% monomer concentration, 3 wt% 4 (relative to monomer) as catalyst, 24 h, 20-40°C. 

Chen, J. H., et al. Influence of Heat Transfer Phenomenon in Nylon Block Copolymer Reaction Molding. SPE-ANTEC, pp. 577-82, May 1989. 

Polymer reaction monitoring has been studied by Siesler [36]. Optical-fiber remote NIRS has been used to monitor the composition of methyl methacrylate (MMA) during the polymerization process, the copolymer reaction of styrene/maleic anhydride with 6-aminohexanoic acid, and the structural changes during the formation of PET film. 

MA copolymer reaction, 283, 430 polyester Michael reaction, 490 Aniline-formaldehyde resins, MA condensations, 513, 516... 

Asymmetric induction polymerization, MA with optically active monomers, 318, 383 Atropine, MA copolymer reaction, 443 Auramine O, EMA resin interactions, 433 Azelaic acid, 151 Azeotrpic copolymer index, 291 Azeotropic copolymerizations, pressure effects, 291 Azepine, acryloyl derivative MA copolymerization, 382... 

Mesityl oxide, MA copolymer reactions, 430, 442 Mesoxalic acid... 

Prednisolone, MA copolymer reaction, 443 Pressure polymerization, MA monomer, 239,... 

It may be observed that before or at the early stage of copolymer reaction the PER/PBNCO mixture is separated into droplet-like domains (see Fig. 32). In contrast, the mixture at the end of the... 

---