Condensation polymerization resin

Unsaturated polyester resins prepared by condensation polymerization constitute the largest industrial use for maleic anhydride. Typically, maleic anhydride is esterified with ethylene glycol [107-21-1] and a vinyl monomer or styrene is added along with an initiator such as a peroxide to produce a three-dimensional macromolecule with rigidity, insolubiUty, and mechanical strength. 

Uses of Formaldehyde. Formaldehyde is the simplest and most reactive aldehyde. Condensation polymerization of formaldehyde with phenol, urea, or melamine produces phenol-formaldehyde, urea formaldehyde, and melamine formaldehyde resins, respectively. These are important glues used in producing particle hoard and plywood. 

Though less prevalent than addition polymerization, condensation polymerization produces important polymers such as polyesters, polyamides (nylons), polycarbonates, polyurethanes, and phenol-formaldehyde resins (Chapter 12). 

This group includes many plastics produced by condensation polymerization. Among the important thermosets are the polyurethanes, epoxy resins, phenolic resins, and urea and melamine formaldehyde resins. 

Polyethylene terephthalate also has the tendency, because it is produced by a condensation polymerization process, to depolymerize under high pressure and temperatures in the presence of water. Although this is usually a negative attribute, it can be utilized to regenerate pure monomers which can be repolymerized to make fresh polymer. This avoids the issues experienced by reprocessing resins, as the new resin has not experienced a previous heat history. A major drawback to this process is the requirement that the monomers used in polymerization processes must be highly pure, Unfortunately, this process is extremely costly and not performed on a commercial scale. 

Vulcanisation of elastomers effected by the incorporation in the compound of certain polymeric resins derived from the condensation of formaldehyde with 4-alkyl phenols. Most frequently used with butyl and EPDM compounds for enhanced heat resistance. 

The solid-phase synthesis of glycopeptides was first realized by applying the polymeric benzyl ester principle of Merrifield. According to this methodology, Lavielle and associates (50) used 7V-(tm-butyloxycarbonyl)-<9-glycosyl serine derivative 153 for condensation with resin-linked alanine 154. 

Ion-exchange polymeric resins are the most important types of exchangers currently in use [113-123], The first, totally organic ion-exchange resin was synthesized in 1935 by Adams and Holmer, when they produced a phenol-formaldehyde cation-exchange resin and an amine-formaldehyde anion-exchange resin, both obtained with the help of condensation polymerization reactions [113], In 1944, D Alelio synthesized styrene-based polymeric resins, which could be modified to obtain both cationic- and anionic-exchange resins. The majority of the resins commercially applied currently are of this type, for example, Amberlite IR-20, Lewatit S-100, Permutit Q, Duolite, C-20, Dowex-50, and Nalcite HCR. 

Many industrial applications utilize the solvent properties of furfural and fur-furyl alcohol however, both chemicals also display unique features as monomers for condensation polymerization. Most of the furfuryl alcohol sold is used as monomer in the manufacture of resins for industrial application. 

Trimethylsilylmethylphenol and o-cresol were obtained from Petrarch Systems, Inc. and Aldrich Chem. Co. Inc., respectively. Silylated novolac (Sl-novolac) resins were prepared by condensation polymerization of p-trimethylsilylmethyl phenol, o-cresol and formaldehyde. Poly(2-methyl-l-pentene-sulfone) (PMPS) was prepared as described in the literature (12). 

The first completely synthetic ion exchange resins were prepared by B. A. Adams and E. L. Holmes in 1935. The basis of their synthesis was the condensation polymerization of methanal (formaldehyde) with phenol or polysubstituted benzene compounds to give, after... 

Scheme 2.1 Condensation polymerization synthesis of a sulfonic acid cation exchange resin...

Many efforts have been made to base polymers on furfural made from pentoses.159 The polymers may be useful, but tend to have lower thermal stability than the usual synthetic polymers. Polyesters based on furfural were mentioned earlier. The acid-catalyzed polymerization of furfuryl alcohol is used in foundry cores.160 Furfural has been condensed with cardanol (m-pentadecadienylphenol) from cashew nut shell oil in the presence of other phenols to produce polymeric resins.161 Cardanol and hydrogenated cardanol have been polymerized with horseradish peroxidase to soluble polymers in up to 85% yield.162 Plasticizers that are effective in polyvinyl chloride, such as (12.31), have been made from furfural.163... 

Acid Catalyzed Condensation Polymerizations. The strong protonic acids produced by the photolysis of onium salts I-III can also be employed to catalyze the condensation of phenolic, melamine, and urea formaldehyde resins. Very durable photoresists based on these inexpensive and readily available resins can be made. Such resists generally require a postbake prior to development to complete the condensation and to enhance image formation. 

The formation of alkyd resins is a typical example of condensation polymerization. In 1847, Berzelius reported a resinous product formed by the reaction of tartaric acid and glycerol. In 1901, Watson Smith (England) prepared a brittle resinous polymer by... 

Polyacrylic resins were employed to study how immobilization resin particle size influences Candida antarctica Lipase B (CALB) loading, fraction of active sites, and catalytic properties for polyester synthesis. CALB adsorbed more rapidly on smaller beads. Saturation occurred in less than 30 seconds and 48 h for beads with diameters 35 and 560-710 pm, respectively. Infrared microspectroscopy showed that CALB forms protein loading fronts for resins with particle sizes 560-710 and 120 pm while CALB appears evenly distributed throughout 35 pm resins. The fraction of active CALB molecules adsorbed onto resins not influenced by particle size was less than 50 %. At about 5% w/w CALB loading, decrease in the immobilization support diameter from 560-710 to 120,75 and 35 pm increased conversion of s-CL to polyester (20 to 36, 42 and 61%, respectively, at 80 min). Similar trends were observed for condensation polymerizations of 1,8-octanediol and adipic acid. 

Recently, our laboratory immobilized CALB on a series of methyl methacrylate resins with identical average pore diameter (250 A) and surface area (500 mVg) but varied particle size (35 to 560-710 pm). CALB adsorbed more rapidly onto smaller beads. Infrared microspectroscopy revealed CALB forms protein loading fronts for resins with particle sizes 560-710 and 120 pm. In contrast, CALB appeared evenly distributed throughout 35 pm resins. Titration with /j-nitrophenyl n-hexylphosphate (MNPHP) showed the fraction of active CALB molecules a orbed onto resins was <50 %. By increasing loading of CALB from 0.9 to 5.7 % (w/w) onto 35 pm methyl methacrylate beads, an increase in the fraction of active CALB molecules from 30 to 43% was observed. Furthermore, by decreasing the immobilization support diameter, a regular increase in e-caprolactone (s-CL) conversion to polyester resulted. Similar trends were observed for condensation polymerizations between 1,8-octanediol and adipic acid. 

Alkyd resins are based on polymeric resins developed in the 1920s. The first alkyd resins sold commercially under the name Glyptal were made by the General Electric Company (Fig. 3.20). Alkyd resins are a class of polyesters synthesized by condensation between an alcohol and an acid or anhydride. Actually, the anhydride is modified with a monofunctional acid, most commonly C g fatty acid, which can be obtained from vegetable oil (rubber seed oil (RSO) or palm oil) [61-63]. The major advantage of the alkyd resins is their components (fatty acids and triglyceride... 

C3N3(NH2)3) a white solid organic compound whose molecules consist of a six-membered heterocyclic ring of alternate carbon and nitrogen atoms with three amino groups attached to the carbons. Condensation polymerization with methanal or other aldehydes produces melamine resins, which are important thermosetting plastics. 

It is produced from para-xylene and ethylene. The p-xylene is converted into either dimethyl terephthalate or terephthalic acid, and the ethylene into ethylene glycol. These monomers are then polymerized by a condensation process, producing water as the byproduct molecule if terephthalic acid is used, and methanol if dimethyl terephthalate is used. Following the condensation polymerization, the molecular weight is increased by solid-stating, in which the dried and crystallized resin chips from the original polymerization are subjected to high temperature and vacuum. 

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