Hydroxy-terminated poly

Hydroxy-Terminated Poly butadiene Propellant Formulation... 

Hie most representative member of this class of polyesters is the low-molar-mass (M 1000-3000) hydroxy-terminated aliphatic poly(2,2/-oxydiethylene adipate) obtained by esterification between adipic acid and diethylene glycol. This oligomer is used as a macromonomer in the synthesis of polyurethane elastomers and flexible foams by reaction with diisocyanates (see Chapter 5). Hydroxy-terminated poly(f -caprolactonc) and copolyesters of various diols or polyols and diacids, such as o-phthalic acid or hydroxy acids, broaden the range of properties and applications of polyester polyols. 

Poly(poly(alkylene terephthalate)-Woc -poly(oxyalkylene)) thermoplastic elastomers are prepared by the bulk polycondensation of dimethyl terephthalate with a mixture of 1,4-alkanediol and hydroxy-terminated poly(oxyalkylene) in... 

Anionic polymerization of lactams was shown to proceed according to what is called the activated monomer mechanism. With bischloroformates of hydroxy-terminated poly(tetramethyleneglycol) and poly(styrene glycol) as precursors for a polymeric initiator containing N-acyl lactam ends, block copolymers with n-pyrrol-idone and e-caprolactam were obtained by bulk polymerizations in vacuum at 30 and 80 °C, respectively361. ... 

A hydroxy-terminated poly(dimethylsiloxane), H0[-Si(CH3)20-] H, is one of the constituents of the formulation known as PermatexJ1 ... 

Recent advances in the development of well-defined homogeneous metallocene-type catalysts have facilitated mechanistic studies of the processes involved in initiation, propagation, and chain transfer reactions occurring in olefins coordi-native polyaddition. As a result, end-functional polyolefin chains have been made available [103].For instance, Waymouth et al.have reported about the formation of hydroxy-terminated poly(methylene-l,3-cyclopentane) (PMCP-OH) via selective chain transfer to the aluminum atoms of methylaluminoxane (MAO) in the cyclopolymerization of 1,5-hexadiene catalyzed by di(pentameth-ylcyclopentadienyl) zirconium dichloride (Scheme 37). Subsequent equimolar reaction of the hydroxyl extremity with AlEt3 afforded an aluminum alkoxide macroinitiator for the coordinative ROP of sCL and consecutively a novel po-ly(MCP-b-CL) block copolymer [104]. The diblock structure of the copolymer... 

Similarly, a series of hydroxy-terminated poly(ether) dendrimers, 35, with a single carborane nucleus at their core, were observed to have water solubilities comparable to that of chloroacetic acid, or D,L-valine. Again this is in direct contrast to the starting carborane nucleus which is insoluble in aqueous solutions and permitted the use of 35 in neutron capture therapy. Similar effects have also been observed with dendrimers containing calixarenes [66] and porphyrins [67] as the central units. 

The maleimide functionality has also been utilized as a modifying group to obtain polymers crosslinkable by free radical chemistry. Thus, hydroxy-terminated poly(oxy-2,6-dimethyl-1,4-phenylene) (164) was treated with p-maleimidobenzoyl chloride (165) to obtain resin (166 Scheme 81) (72FRP2122181). Resin (166) melted at 155 °C and could be coated on to... 

Nafion-H has also been used as a catalyst for the oligomerization of styrene. The reaction was studied by Higashimura and co-workers.933,934 Hydroxy-terminated poly (alkylene)oxides were prepared by condensation-polymerization of 1,8-octanediol and 1,10-decanediol in the presence of Nafion-H.935 It showed higher activity than sulfuric acid consequently, polymerization could be carried out at lower temperature. 

Caliceti P., O. Schiavon, M. Morpurgo, F.M. Veronese, L. Sartore, E. Ranucci, and P. Fermti. 1995. Physico-chemical and biological properties of monofunctional hydroxy terminating poly (N-vinylpyrroli-done) conjugated superoxide dismutase. 

Recently, a,co-bis-hydroxy-terminated poly(l,3-propylene succinate) has been chain-extended to yield high molecular weight poly(ester-carbonates) [44] using a bischloroformate route. Thus, using a molar ratio of 1,3-propanediol to succinic acid of 1.02, an oligomer having Mn of 2,200 and Mw of 3,000 was ob-... 

Coextrusion of L-lactide (a cyclic dimer lactone of lactic acid) with hydroxy-terminated poly(caprolactone) in the presence of stannous octoate gave a block copolymer.74 Block copolymers can also be used as compatibilizers for the homopolymers, in addition to having interesting properties in their own right.75 Copolymers of ethylene and vinyl acetate can be treated with methanol and a little sodium methoxide to remove some of the acetate groups from the copolymer.76 The by-product methyl acetate comes out the vent of the extruder. n-Butyl alcohol can be used in the same way.77 The product copolymer is useful as a gas barrier coating on films for packaging food. 

Hydrophobic silica production via batch processes is somewhat different. A slurry of hydrophilic silica in oil is treated with the hydrophobic agent and a catalyst. The hydrophobic agent may be either silicone polymer containing a reactive end group or a small reactive silicon-containing molecule such as trimethylchlorosilane. Typical silicone polymers used in this process are hydroxy-terminated poly(dimethylsiloxane)s. The catalyst... 

Figure 3 shows an example of the reaction as carried out using a hydroxy-terminated poly(dimethylsiloxane). Extent of reaction is measured for this, and the continuous process, by hydrophobic index (HI). HI is measured by placing hydrophobic silica in water that contains varying percentages of an alcohol. The percent alcohol at which the silica starts to become wet (sink in the solution) is defined as its hydrophobic index. 

Predominantly di-end-functional polymers may be prepared by conducting polymerizations with high concentrations of a functional initiator. Some of the first commercial products of this class, carboxy and hydroxy-terminated poly butadienes, were produced by this route. 

Fig. 6. Separation of hydroxy-terminated poly(butylene glycol terephthalate) as a function of the mobile phase composition stationary phase silica gel mobile phase THF-heptane peaks 1.2 solvent, peaks 3-7 nonfunctional homologues (n = 0-4), peaks 8-12 monofunctional homologues (n = 0-4), peaks 13-17 bifunctional homologues (n = 04). (From [2] with permission)...

Synonyms Dimethyl silicones and siloxanes, hydroxy-terminated Dimeth-yisiloxane, hydroxy-terminated Poly [oxy (dimethylsilylene)], a-hydro-co-hydroxy- Siloxanes and silicones, dimethyl, hydroxy-terminated Definition Dimethyl silicone terminated with hydroxyl groups Properties Anionic Toxicology TSCA listed... 

Sax Saxena, A., Francis, B., Rao, V. L., Ninan, K. N. Toughening of an epoxy resin with hydroxy-terminated poly (aiylene ether nitrile) with pendent tertiary butyl groups. J. Appl. Polym. Sci. 

FrOlich et al. [ 140] investigated a system in which DGEBA was mixed with hydroxy-terminated poly(propylene oxide-block-ethylene oxide) as the rubber, with the nanoclay being a synthetic fluorohectorite treated with bis (2-hydroxyethyl) methyl tallow alkylammonium ions. The clay was first blended with rubber, before being dispersed into the reactive epoxy mixture. Modification of the rubber allowed variation in miscibility and differing morphologies and properties. If the rubber was miscible, the intercalated clay led to improved toughness. If the rubber is sufficiently modified, such as with... 

Hergenrother and Ambrose have prepared butadiene-imide and butadiene-caprolactam(73,74)block copolymers using polybutadiene capped on each terminus by isocyanate groups. Poly(ethylene-propylene adipate-b-methyl methacrylate) was prepared by heating hydroxy terminated poly(methyl methacrylate) with the isocyanate terminated reaction products of hydroxy terminated poly(ethylene-propylene... 

Isophthaloyl chloride has also been employed in block copolymer preparation. Poly(m-phenylene isophthalamide) and either poly-(ethylene oxide) or poly(dimethyl siloxane) block copol3miers have been prepared by terminating the former with isophthaloyl chloride and subsequently adding hydroxy terminated poly(ethylene oxide) or poly(dimethyl siloxane)(79). Block copolymers were also produced when a polyformal was capped with 1,6-hexandiol, and then heated in the presence of poly(tetramethylene terephthalate)(80). In another interesting application, polyesterpolyether block copolymers of poly-(ethylene terephthalate) and a number of polyglycols have been reported(Sl). Their synthesis involves esterification, catalyzed by zinc acetate/titanyl oxalate. ABA block polymer of 2-hydroxyethyl methacrylate and styrene was prepared by coupling -NH2 terminated PHEMA and isocyanate terminated polystyrene. The latter material was prepared by UV polymerization of styrene in the presence of bis(p-isocyanatophenyl)disulfide (82),... 

FuUy biobased poly(L-lactide)-b-poly(ricinoleic acid)-b-poly(L-lac-tide) triblock copolyesters have been described (31). Methyl ri-cinoleate, produced from castor oil, is condensed in the presence of a small amount of 1,3-propanediol. This results in a a, (D-hydroxy-terminated poly(ricinoleic acid) with a molar mass... 

Chain Transfer to Organometallic Compounds. Hydroxy-terminated poly(methylene-l,3-cyclopentane) has been prepared by selective chain transfer to aluminum in the cyclopolymerization of 1,5-hexadiene with the sterically... 

An activated monomer mechanism similar to that described for oxiranes has been proposed to account for the formation of hydroxy-terminated poly(DXL) (320). 

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