EO block copolymers

Santos et al. [128,129] and Guerrero et al. [130] prepared segmented poly(EO) containing bistrialkylbenzopinacolate moieties to synthesize poly(St)-poly(EO) block copolymers. The St polymerization with the polymeric iniferter 27 was comparable to that initiated with small molecular benzopinacolates. 

Unfortunately, DMC catalysts are not efficient for EO polymerisation, and it is practically impossible to obtain PO-EO block copolymers with this catalyst. Acidic catalysts are not used on an industrial scale for alkylene oxide polymerisation due to the formation of substantial amounts of cyclic ethers as side products. Acidic catalysts are used industrially only for the synthesis of polytetrahydrofuran polyols or, to a lesser extent, for tetrahydrofuran - alkylene oxide copolyether polyol fabrication (see Sections 7.1, 7.2 and 7.3) Other catalysts have a minor importance for large scale polyether polyol production. 

The most important polyether, PO-EO block copolymer structures, having terminal poly[EO] block (structure a) and internal poly[EO] block (structures b and c), are presented in Figure 4.28. 

The most important polyether triol, PO-EO block copolymers with poly[EO] block, used in practice, are ... 

Table 4.10 Characteristics of polyether triol, based on glycerol PO-EO block copolymers (terminal block) with a MW of 3000 daltons ...

The polyether triols (PO-EO block copolymers with terminal poly[EO] block) are very reactive polyols due to the presence of a high percentage of primary hydroxyls. These polyether polyols with terminal poly[EO] block, are used preferentially for moulded flexible PEI foams. 

In Sections 4.1, 4.1.1, 4.1.2, 4.1.3 and 4.1.4, the chemistry of polyether polyol synthesis, the mechanism and kinetics of alkylene oxide polyaddition to hydroxyl groups and the most important structures of polyalkylene oxide polyether polyols for elastic polyurethanes - PO homopolymers, random PO-EO copolymers and PO-EO block copolymers - were discussed. 

Tables 4.9-4.14 show some general characteristics of polyether polyol PO-EO block copolymers, such as MW, hydroxyl number, functionality, viscosity and colour, but also some other characteristics such as unsaturation, EO content, and potassium and sodium content which are specific for polyether polyols.

The advantage of phosphazenium catalysts, compared to DMC, is their capability to catalyse the anionic polymerisation of PO and EO and to be used successfully in the synthesis of PO-EO block copolymers with terminal poly[EO] block, without intermediate change of the catalyst nature. 

Excellent PO-EO block copolyether polyols with terminal poly[EO] block, are formed by the addition, to the intermediate propoxylated polyether obtained with DMC catalysts, of an anionic catalyst (KOH or potassium alcoholates) followed by the addition of EO by classical technology, via an anionic mechanism. By this relatively complicated route, it is possible to obtain PO-EO block copolymers with high primary hydroxyl content and very low unsaturation. 

All the aromatic polyesters based on DEG have poor compatibility with blowing agents (pentanes or fluorocarbons) and to improve this compatibility compatibilising polyols such as ortho-toluene diamine polyols, propoxylated a-methyl glucoside polyols, oxyethylated p-nonylphenol, amine and amide diols, PO-EO block copolymers, borate esters, silicone compounds and so on, are frequently used [27-30]. 

Pluronk . [BASF BASF AG] PO/EO block copolymers emulsifier, wetting agent, binder, stabilizer, plasticizer, lubricant, solubilizer, dispersant, vise, ctmtrcd agent, defoamer, intermediate for detergents, textiles, cosmetics, pharmaceuticals, pulp, paper, petroleum, agric., wat treatment... 

Figure 1. Cross polarized photomicrographs of films of EO-Is-EO block copolymers with relatively large fractions of EO segments revealing less perfect development of spherulitic crystalline texture as the Is content increases...

Figure 2. Electron micrographs of ultrathin films of EO-Is-EO block copolymers...

DBDPO. See Decabromodiphenyl oxide DBE. See Ethylene dibromide DBE-4. See Dimethyl succinate DBE-5. See Dimethyl glutarate DBE-6. See Dimethyl adipate DBE-224, DBE-621, DBE-712, DBE-814, DBE-821. See Dimethylsiloxane/EO copolymer DBE-C25. See EO/dimethylsiloxane/EO block copolymer... 

See aiso Dimethylsiloxane/EO copolymer EO/dimethylsiloxane/EO block copolymer Silicone glycol copolymer Dimethicone copolyol acetate Definition Partial ester of dimethicone copolyol and acetic acid... 

Enzymes, mammalian placenta Enzymes, placental. See Placental enzymes EO. See Ethylene oxide E.O.D.. See Octyldodecyl erucate EO/dimethylsiloxane/EO block copolymer CAS 68937-54-2... 

Caprolactone/dimethylsiloxane/caprolactone block copolymer EO/dimethylsiloxane/EO block copolymer PO-dimethylsiloxane-PO block copolymer Polydimethylsiloxane, hydroxyethoxypropyl-terminated lubricant, resin-bonded film Molybdenum disulfide lubricant, resins Lithium stearate lubricant, rigid PVC Cetearyl alcohol lubricant, rinse aids... 

Dodoxynol-11 Dodoxynol-12 Dodoxynol-14 EO/dimethylsiloxane/EO block copolymer EO/PO block polymer or copolymer Epoxidized linseed oil, butyl ester Epoxidized linseed oil, 2-ethylhexyl ester Epoxidized linseed oil, methyl ester Epoxidized soybean oil, butyl ester Epoxidized soybean oil, methyl ester... 

Dimethicone copolyol Dimethylsiloxane/EO copolymer Dow Corning 5103 Surfactant EO/dimethylsiloxane/EO block copolymer PS071... 

EO/PO/EO block copolymers are produced by first forming a block of PO via propoxylation of propylene glycol to the desired polymeric size (to form the hydrophobe), followed by ethoxylation of the polypropylene oxide chain (see Figure 13.14). Propylene oxide is less reactive than ethylene oxide, and requires slightly more rigorous conditions for efficient propoxylation. 

EO/PO/EO block copolymers are very low-foaming surfactants. As a result of hydrogen bonding, the ethoxylate chain (and to a lesser extent, the propoxylate chain) add structure to aqueous formulations, and are therefore used as thickening and gelling agents. They are also mild, but relatively expensive. 

EO/PO/EO block copolymer where m = 0 or higher, and n = 1 or higher depending on degree of propoxylation and ethoxylation... 

In general, increasing EO content increases the water solubility, improves the ability to thicken and form gels, and reduces wetting. PO/EO/PO block copolymers foam less, are more effective defoamers, and have less of a tendency to form gels in aqueous solutions than EO/PO/EO block copolymers. 

Synthetic pyrethroid PO-EO block copolymer Castor oil ethoxylate 40 EO N-Octyl pytrolidone N-Methyl pytrolidone... 

Chem. Descrip. PO/EO block copolymer Ionic Nature Nonionic CAS 9003-11-6... 

---