Polycondensation, of ethylene glycol

Condensation polymerization differs from addition polymerization in that the polymer is formed by reaction of monomers, each step in the process resulting in the elimination of some easily removed molecule (often water). E.g. the polyester polyethylene terephthalate (Terylene) is formed by the condensation polymerization (polycondensation) of ethylene glycol with terephthalic acid ... 

Hoftyzer, P. J., Kinetics of the polycondensation of ethylene glycol terephthalate, Appl. Polym. Symp., 26, 349-363 (1975). 

Raw stock organochlorosilanes methyltrichlorosilane, dimethyldichlo-rosilane, methylphenyldichlorosilane or phenyltrichlorosilane with the main substance content of at least 99.0-99.8% toluene (the boiling point is 109.5-111 °C, d420 = 0.865 0.002) butyl alcohol (the boiling point is 115-118 °C) polyester, the product of the polycondensation of ethylene glycol with phthalic and maleic anhydride ... 

Diethylzinc was used as a catalyst for the preparation of polyesters from terephthalaldehyde via the Tischenko reaction (480), and for the polycondensation of ethylene glycol with dimethyl terephthalates to afford polyethylene terephthalate (340). Benzylzinc chloride has been used as a catalyst for polycondensation of benzyl chloride (223). 

Polyphosphates derived from 4,4 -dihydric phenols or 4,4 -isopropylidenebis-phenol, bis(2,6-dibromophenol) and having an active moiety like 154 impart flame retardant properties [ W]. Thermostable polyesters were prepared by addition of bis(2-hydroxyethyl)phosphate prior to the final step of the polycondensation of ethylene glycol with dimethyl terephthalate [205]. Zinc salt of polydithiophosphate obtained by reaction of phosphorus pentasulfide with 4-substituted anisole was tested as AO in lubricating oils and greases. 

Polyethyleneterephthalate (PETP) is widely used in industry as fibres and films. PETP belongs to thermoplastic ethers and is a product of polycondensation of ethylene glycol and dimethylterephthalic acids [186],... 

Polyethylene terephthalate (PET) (Table 5.3.13) is obtained either by polycondensation of ethylene glycol and terephthalic acid or by transesterification of terephthalic add dimethyl ester with ethylene glycol. The polymer has an unusually high melting point (260-270 °C) and very good mechanical properties. PET botdes and textile as well as industrial fiber applications are among the main applications of this polyester. 

Obtained by the cationic polymerization of 1,3-dioxolan, 2-methyl-l,3-dioxolan, 4-tnethyl-l,3-dioxolan, 2,2 -dietl5fl-l,3-dioxolan. Or it can be obtained from the polycondensation of ethylene glycol and formaldehyde. 

Terylene—one of the best polyester fibres— is a product of the polycondensation of ethylene glycol with terephthalate-polyglycolterephthalate. 

For the polymerization, either in the melt or solid phase, the reaction is driven to the polymer by removing ethylene glycol. The polymerization reaction is typically catalyzed by solutions consisting of antimony trioxide or germanium oxide. Both polycondensation catalysts also catalyze the reverse reaction, which is driven by an excess of ethylene glycol at melt conditions, generally above 255 °C. The polymerization reaction follows second-order kinetics with an activation energy of 22 000 cal/mol [6],... 

These are the polycondensation products of dlcarboxylic acids and diols. Dacron or terylene Is the best known example of polyesters. It is manufactured by heating a mixture of ethylene glycol and terephthallc acid at 420 to 460 K In the presence of zinc acetate-antimony trioxlde catalyst as per the reaction given earlier. Dacron fibre (terylene) is crease resistant and is used In blending with cotton and wool fibres and also as glass reinforcing materials in safety helmets, etc. 

For polycondensation reactions such as the final poly condensation of polyester, the reaction equilibrium and the reaction rate are mainly influenced by the removal of ethylene glycol (13) ... 

Diffusion of ethylene glycol through the high-viscosity reaction system is the apparent rate-determining step in PET polycondensation. Preliminary examination of many univalent hydroxyl compounds shows that water and phenol diffuse much more readily through molten PET than does ethylene glycol. Therefore, a bifunctional reagent that re-... 

Polycondensation Reaction. Transesterification was carried out in the conventional manner (4) with 97 grams (0.50 mole) of dimethyl terephthalate (DMT) and 69 grams (1.10 moles) of ethylene glycol in the presence of 0.088 gram of Ca(OAc)2 H20 and 0.044 gram of Sb203 at 160°-230°C. After completing the transesterification, 0.080... 

The polycondensation reaction to give the desired polymer, 8.18, is carried out at high temperatures (>260°C) in the presence of Sb203 and Ti-alkoxide catalysts. The roles of the catalysts at the molecular level are not known in any detail. As shown by reaction 8.26, in the polycondensation reaction one molecule of ethylene glycol is also generated for each molecule of the monomer. 

Polyurethane [117] and polyester [118] particles have also been prepared by the dispersion polyaddition of ethylene glycol (EG) and toluene diisocyanate (TDI) in paraffin, and the polycondensation of acid and ester at a high polymerization temperature, respectively. Table 3 provides an overview of microspheres of monomers other than vinyl monomers obtained by dispersion polymerization. 

Branched polymers in solution also show concentration-dependent transitions in viscosity. Copolymers of poly(ethylene terephthalate-co-ethylene isophthalate) (P(ET-co-EI)) were prepared by the polycondensation reaction of an equimolar mixture of dimethyl terephthalate (DMT) and dimethyl isophthalate (DM1) in the presence of a 100% excess of ethylene glycol (EG) (Scheme 3.1). Chain branching was introduced into the polymer using a tri-functional anhydride or a tricarboxylate at a level of 1 -1.5 molar percent. The concentration dependence of viscosity for these polymers were Tjsp ... 

Resins with long-chain macromolecules obtained by polycondensation have thermoplastic properties. Polyesters ( Terylene ) and polyamides (Nylon) are examples of polycondensations. The synthetic fibre Terylene (known as Dacron in the USA) is a polyester formed by the reaction of ethylene glycol with terephthalic acid the latter is obtained from p-xylene by oxidation ... 

Polyethylene terephthalate is the linear polycondensation product of ethylene glycol and terephthalic acid... 

As described in Section 11.2.3.3.3, APES can be biodegradable depending on their chemical formulation. Park et al. [351] prepared bionanocomposites of a biodegradable APES prepared by polycondensation of aliphatic glycols (ethylene glycol and 1,4-butanediol) and ahphatic dicarboxylic acids (succinic and adipic acids), TPS, and MMT (Cloisite 30B) via melt intercalation. They found that adding APES to the TPS/Cloisite 30B hybrids led to higher TS and improved barrier properties. 

A polycondensation reaction takes place between 1.2 moles of a dicarboxylic acid, 0.4moles of glycerol (a triol) and 0.6moles of ethylene glycol (a diol). 

---