Polymers hydroxyl terminated

All oligo-polyols have terminal hydroxyl groups, being in fact telechelic, low MW polymers (hydroxyl terminated telechelic oligomers). 

Chem. Descrip. Butadiene polymer, hydroxyl-terminated CAS 69102-90-5... 

Uses. The largest uses of butanediol are internal consumption in manufacture of tetrahydrofuran and butyrolactone (145). The largest merchant uses are for poly(butylene terephthalate) resins (see Polyesters,thermoplastic) and in polyurethanes, both as a chain extender and as an ingredient in a hydroxyl-terminated polyester used as a macroglycol. Butanediol is also used as a solvent, as a monomer for vadous condensation polymers, and as an intermediate in the manufacture of other chemicals. 

The most widely used sUicones are polymers of methyl(hydrogen)sUoxane and of dimethylsiloxane. Polydimethylsiloxane is the basic polymer used in sUicone repeUents. If the polymer is terminated with methyl groups it is inert however, if it is terminated with hydroxyl groups, it can be cross-linked. Continuous, durable coatings result from the use of curable blends of polydimethyl siloxane and polymethyl(hydrogen)sUoxane. The sUicone finish encapsulates individual fibers. 

The outer surfaces of these plasma polymers are terminated with hydroxyl groups and have high surface energies. They are readily wet by adhesives and form strong and durable adhesive bonds [51]. 

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]. 

Generation of radicals by redox reactions has also been applied for synthesizing block copolymers. As was mentioned in Section II. D. (see Scheme 23), Ce(IV) is able to form radical sites in hydroxyl-terminated compounds. Thus, Erim et al. [116] produced a hydroxyl-terminated poly(acrylamid) by thermal polymerization using 4,4-azobis(4-cyano pentanol). The polymer formed was in a second step treated with ceric (IV) ammonium nitrate, hence generating oxygen centered radicals capable of starting a second free radical polymeriza-... 

Brosse, J.-C., Derouet, D., Epaillard, F., Soutif, J.-C., Legeay, G. and Dusek, K. Hydroxyl-Terminated Polymers Obtained by Free Radical Polymerization. Synthesis, Characterization, and Applications. Vol. 81, pp. 167—224. 

The effects of the feed ratio in the lipase CA-catalyzed polymerization of adipic acid and 1,6-hexanediol were examined by using NMR and MALDI-TOF mass spectroscopies. NMR analysis showed that the hydroxyl terminated product was preferentially formed at the early stage of the polymerization in the stoichiometric substrates. As the reaction proceeded, the carboxyl-terminated product was mainly formed. Even in the use of an excess of the dicarboxylic acid monomer, the hydroxy-terminated polymer was predominantly formed at the early reaction stage, which is a specific polymerization behavior due to the unique enzyme catalysis. 

Poly(methyl 3-(l-oxypyridinyl)siloxane) was synthesized and shown to have catalytic activity in transacylation reactions of carboxylic and phosphoric acid derivatives. 3-(Methyldichlorosilyl)pyridine (1) was made by metallation of 3-bromopyridine with n-BuLi followed by reaction with excess MeSiCl3. 1 was hydrolyzed in aqueous ammonia to give hydroxyl terminated poly(methyl 3-pyridinylsiloxane) (2) which was end-blocked to polymer 3 with (Me3Si)2NH and Me3SiCl. Polymer 3 was N-oxidized with m-ClC6H4C03H to give 4. Species 1-4 were characterized by IR and H NMR spectra. MS of 1 and thermal analysis (DSC and TGA) of 2-4 are discussed. 3-(Trimethylsilyl)-pyridine 1-oxide (6), l,3-dimethyl-l,3-bis-3-(l-oxypyridinyl) disiloxane (7) and 4 were effective catalysts for conversion of benzoyl chloride to benzoic anhydride in CH2Cl2/aqueous NaHCC>3 suspensions and for hydrolysis of diphenyl phosphorochloridate in aqueous NaHCC>3. The latter had a ti/2 of less than 10 min at 23°C. 

We can make polyurethanes via one- or two-step operations. In the single-stage process, diols and isocyanates react directly to form polymers. If we wish to make thermoplastic linear polymers, we use only diisocyanates. When thermosets are required, we use a mixture of diisocyanates and tri- or polyisocyanates residues of the latter becoming crosslinks between chains. In the first step of the two-stage process, we make oligomers known as prepolymers, which are terminated either by isocyanate or hydroxyl groups. Polymers are formed in the second step, when the isocyanate terminated prepolymers react with diol chain extenders, or the hydroxyl terminated prepolymers react with di- or polyisocyanates. 

We create polyurethanes from prepolymers by chain extension. In the case of hydroxyl-terminated prepolymers the chain extender is an isocyanate. If we use a diisocyanate, the resulting polymer is linear. If we substitute some or all of the diisocyanate with a tri- or... 

Model networks were prepared using hydroxyl terminated polymer and isocyanates, (a) Bifunctional hydroxyl terminated polybutadiene (Butarez, from Phillips Petroleum) was crosslinkined with tris (p-isocyanatophenyl)-thiophosphate (Desmodur RF, from Mobay Chemical Co.). This crosslinked... 

Further work related to the synthesis of copolymers with either P2VP or P4VP blocks has been reported in the literature. Triblock terpolymers PS-fc-P2VP-fo-PEO were synthesized in THF at - 78 °C by sequential polymerization of styrene and 2VP, initiated by s-BuLi in the presence of IiCl [25]. The living polymer was terminated with EO. The end-hydroxyl group was... 

The use of these initiators to polymerize LA814 and methylglycolide815 has been reported to proceed in a well-controlled fashion. Block copolymers such as PCL-b-PLA have also been prepared. Elimination of PrOH from the reaction of (270) with preformed hydroxyl terminated polymers, followed by lactone polymerization, yields diblocks of CL with polystyrene or polybutadiene.816 The preparation of an ABA triblock has also been reported (A = CL, B = LA) since propagating chains of PLA do not initiate CL ring opening, (270) was pretreated with hydroxy terminated (PCL-b-PLA)-OH 814... 

The diisocyanates and polyols are reacted to form a high molecular weight hydroxyl terminated millable gum. These millable gums are compounded and processed as conventional elastomers, both sulphur and peroxides being used to cure the polymers. Here again, polyether and polyester types are available, and the differences between these two types referred to above also apply here. 

The hydroxyl-terminated polymer was then added to the dispersion and the mixture allowed to stand for 24 hr to achieve adsorption equilibrium. Further n-heptane was then added to give a 4 1 (by volume) n-heptane ethanol solvent composition, and the sample... 

The first study with an oxygen compound which was sufficiently rigorous to provide evidence on the question of co-catalysis was that of Farthing and Reynolds [61]. They showed that 3,3-bischloromethyl oxetan could be polymerised in methyl chloride solution by boron fluoride only in the presence of water. Tater, Rose [62] obtained kinetic evidence for the need for a co-catalyst in the system oxetan—boron fluoride—methyl chloride, and he interpreted the low reaction rate when no water was added as due to residual water he also showed that water and a hydroxyl-terminated polymer could act as co-catalysts. 

Characterization of Hydroxyl-Terminated Liquid Polymers of Epichlorohydrin... 

The cationic ring-opening polymerization of epichlorohydrin in conjunction with a glycol or water as a modifier produced hydroxyl-terminated epichlorohydrin (HTE) liquid polymers (1-2). Hydroxyl-terminated polyethers of other alkylene oxides (3 4), oxetane and its derivatives (5 6), and copolymers of tetrahydrofuran (7-15) have also been reported. These hydroxyl-terminated polyethers are theoretically difunctional and used as reactive prepolymers. 

Table 1. Functionality of Hydroxyl-Terminated Epichlorohydrin Liquid Polymers 3)...

Carbon-13 NMR spectra. A carbon-13 NMR spectrum of HTE polymer (Rn S 500) is shown in Figure 3. The carbon-13 NMR spectra of HTE polymers show the carbon chemical shifts at 79.3 and 72.7 ppm for the backbone and the terminal methine carbons respectively, at 43.9 and 46.2 ppm for the backbone and the terminal chloromethyl carbons, respectively, and in the range of 69.7-72.0 ppm as a multiplet for the methylene carbon. It is a characteristic feature of hydroxyl-terminated polyethers that the terminal carbon exhibits a up-field shift due to the substituent effect of the hydroxyl group, whereas the (0 carbon(s) to the terminal hydroxyl group exhibits a down-field shift (Table III). The terminal methine carbon also suggests that the hydroxyl groups are predominantly secondary. 

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