Poly condensation copolymerization

Poly( w-carborane-siloxane) rubbers are most commonly prepared by a ferric chloride-catalyzed bulk condensation copolymerization of dichloro- and dimethoxy-terminated monomers with alkylchloro- or arylchloro-siloxanes.16... 

Comparison of the Two Reactions Step-Growth Polymerization in More Detail Making PET in the Melt Interfacial Poly condensation Chain-Growth Polymerization in More Detail Free Radical Chain Polymerization Going One Step Better Emulsion Polymerization Copolymerization Ionic Chain Polymerization It Lives ... 

The low heat deflection temperature of PLA limits its use for several application fields, such as in packaging materials and electronic components. The introduction of rigid building blocks [63] or cross-links [64] is known, for instance, to increase the glass transition temperature and/or heat resistance of lactic acid based polymers. The effect of different amounts of comonomers in the prepolymers on the Tg and mechanical properties of poly(ester-urethane)s is demonstrated in Table 3.2. The heat resistance of poly(ester-ure-thane)s can be improved by the copolymerization of lactic acid with D,L-mandehc acid. This broadening of the operating temperature range is of clear practical importance. The incorporation of other comonomers that impede rotation and make polymer chains less mobile also causes an increase in Tg, even if the same comonomers can depress the rate of poly condensation [50]. 

For several decades, carbon black and fumed silica have been used in tires, tubings, sealants and so on.[162,163] More recently, functionalized silica nanoparticles were reported to copolymerize with MMA to produce transparent films with good surface finish and controllable refractive index. [162] The sol-gel process is another research topic to prepare the polymer nanocomposites. The principal sol-gel process includes two steps the formation of a colloidal suspension, i.e. sol, and the gelation of the sol to formulate a network in a continuous liquid phase, i.e. gel. For example, the hydrolysis and poly condensation of silicon alkoxides in the presence of MMA will produce a polymer nanocomposite with superior optical and mechanical properties.[163]... 

PEAs can be synthesized by statistical condensation copolymerization of polyamide monomers (PA 6 or PA 6.6), adipic acid, and 1,4-butanediol (Scheme 11.4). A variety of amino acids and aliphatic diols, poly(ethylene glycol), or cyclic diols like dianhydrosorbitol or dianhydromannitol have also been used to prepare PEAs [109,119, 120]. 

VDP Polyimides. Polyimide films have also been prepared by a kind of VDP (16). The poly(amic acid) layer is first formed by the coevaporation and condensation of two monomers, followed by copolymerization on the substrate. The imidization is carried out in a separate baking step (see POLYIMIDES). 

Apart from poly(ethylene glycol), other hydroxyl-terminated polymers and low-molecular weight compounds were condensed with ACPC. An interesting example is the reaction of ACPC with preformed poly(bu-tadiene) possessing terminal OH groups [26]. The reaction was carried out in chloroform solution and (CH3CH2)3N was used as a catalyst. MAIs based on butadiene thus obtained were used for the thermally induced block copolymerization with styrene [26] and dimethyl itaconate [27]. 

Only syntheses which involve the formation of new glycosidic linkages will be considered in this article. This restriction excludes many interesting examples of copolymerization in which only one of the monomers is a carbohydrate (or carbohydrate derivative), the polymerization of carbohydrate derivatives which contain a polymerizable group4 (such as acrylate), and the polymerization of sugar lactones.1 Many of these topics have already been discussed in reviews.1-8 Also outside the scope of this article is the chemical modification of naturally occurring polysaccharides thus, we have excluded the industrially important process of dextrini-zation,10 except as it may pertain to acid condensation processes. The radiation-catalyzed polymerization and modification of carbohydrate poly-... 

The process for preparing linear poly-p-xylylenes by pyrolytic polymerization of di-p-xylylenes has been extended to include the formation of p-xylylene copolymers. Pyrolysis of mono-substituted di-p-xylylenes or of mixtures of substituted di-p-xylylenes results in formation of two or more p-xylylene species. Copolymerization is effected by deposition polymerization on surfaces at a temperature below the threshold condensation temperature of at least two of the reactive intermediates. Random copolymers are produced. Molecular weight of polymers produced by this process can be controlled by deposition temperature and by addition of mercaptans. Unique capabilities of vapor deposition polymerization include the encapsulation of particulate materials, the ability to replicate very fine structural details, and the ability of the monomers to penetrate crevices and deposit polymer in otherwise difficultly accessible structural configurations. 

Copolymerization of Chloro- and Dichloro-/>-xylylene. Trichloro-di-p-xylylene (XVIII) was obtained by chlorination of di-p-xylylene with three molar equivalents of chlorine. Pyrolysis yielded monomers XV and XIX, which were condensed and polymerized on a 90 °C. surface. A quantitative yield of product was obtained. The product was transparent, tough, self-extinguishing, had a softening point above 280°C., and exhibited the correct elemental analysis for copolymer XX. Owing to the low solubility of the chlorinated poly-p-xylylenes, no attempts... 

Polyamide copolymers containing a macromolecular graft substituent were prepared by condensing 4-amino-benzoic acid or a mixture of 1,4-phenylene diamine and adipic acid with 33%, 66%, and 90% 5-(poly(n-butylacrylate)cysteine macromonomer. A second macromolecular monomer, 5-(poly(methyl methacrylate)-cysteine, was also prepared and free radically copolymerized with perfluoromethyl methacrylate. 

The telechelica,(i -bis(2,6-dimethylphenol)-poly(2,6-dimethylphenyl-ene oxide) (PP0-20H) [174-182] is of interest as a precursor in the synthesis of block copolymers [175] and thermally reactive oligomers [179]. The synthesis has been accomplished by five methods. The first synthetic method was the reaction of a low molecular weight PPO with one phenol chain end with 3,3, 5,5 -tetramethyl-l,4-diphenoquinone. This reaction occurred by a radical mechanism [174]. The second method was the electrophilic condensation of the phenyl chain ends of two PPO-OH molecules with formaldehyde [177,178], The third method consists of the oxidative copolymerization of 2,6-dimethylphenol with 2,2 -di(4-hydroxy-3,5-di-methylphenyl)propane [176-178]. This reaction proceeds by a radical mechanism. A fourth method was the phase transfer-catalyzed polymerization of 4-bromo-2,6-dimethylphenol in the presence of 2,2-di(4-hy-droxy-3,5-dimethylphenyl)propane [181]. This reaction proceeded by a radical-anion mechanism. The fifth method developed was the oxidative coupling polymerization of 2,6-dimethylphenol (DMP) in the presence of tetramethyl bisphenol-A (TMBPA) [Eq. (57)] [182],... 

Scheme 13 General route to branched poly(acrylic acid) (PAA) via self-condensing vinyl copolymerization (SCVCP) of an inimer, AB and a monomer, M, followed by hydrolysis...

The self-condensing copper-catalyzed polymerization of macromonomer of poly(tBA) with a reactive C—Br bond (H-6) affords hyperbranched or highly branched poly(tBA).447 Copolymerization of H-1 and TV-cyclohexylmaleimide induced alternating and self-condensing vinyl polymerization.448 The residual C—Cl bond was further employed for the copper-catalyzed radical homopolymerization of styrene to give star polymers with hyperbranched structures. Hyperbranched polymers of H-1 further serve as a complex multifunctionalized macroinitiator for the copper-catalyzed polymerization of a functional monomer with polar chromophores to yield possible second-order nonlinear optical materials.325... 

In the above condensation resist designs, the phenolic resin offers a reaction site as well as base solubility. Self-condensation of polymeric furan derivatives has been utilized as an alternative crosslinking mechanism for aqueous base development (Fig. 126) [375]. The copolymer resist is based on poly[4-hydroxy-styrene-co-4-(3-furyl-3-hydroxypropyl)styrene], which was prepared by radical copolymerization of the acetyl-protected furan monomer with BOCST followed by base hydrolysis. The furan methanol residue, highly reactive toward electrophiles due to a mesomeric electron release from oxygen that facilitates the attack on the ring carbons, readily yields a stable carbocation upon acid treatment. Thus, the pendant furfuryl groups serve as both the latent electrophile and the nucleophile. Model reactions indicated that the furfuryl carbocation reacts more preferentially with the furan nucleus than the phenolic functionality. 

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