Polytetramethylene oxide

The effect of carboxylate and/or sulfonate ion incorporation on the physical and blood contacting properties of polyurethanes was studied by Cooper and collaborators [476-478]. Specifically, propyl sulfonate and ethyl carboxylate groups were grafted onto polytetramethylene oxide-based polyurethanes. Carboxylate polymers had no statistically significant effect on canine ex vivo blood contact response, but propyl sulfonate incorporation significantly reduced platelet deposition for very short blood contact times. 

Ti and Zr containing polytetramethylene oxide (PTMO) ceramic hybrid materials have lately been prepared by a sol-gel technique [61, 62]. Trialkoxy silane capped organic oligomer (PTMO or polyarylene ether sulfones) backbones with titanium isopropoxide or Zr-(n-propoxide) are used in this process ... 

The monomer, commonly known as tetrahydrofuran, has the systematic name tetramethylene oxide or 1,4-epoxybutane. The polymer derived from it is as often called polytetramethylene oxide as polytetrahydrofuran. In accordance with Chemical Abstracts practice, we have chosen to use the names tetrahydrofuran (THF) and polytetrahydrofuran (PTHF). 

DBU DMC DMF EC EO EOS GSS ILs MBMTBP MEA MW PC PDMS PEG PEGda PEO PMPS PO PPG PPGda PTC PTHF PTMO PVP Diazabicyclo[5.4.0] -undec-7-ene Dimethylcarbonate Dimethylform amide Ethylene carbonate Ethylene oxide, oxyethylene Equation of state Gas-saturated solution Ionic liquids 2,2,-methylene-bis(4-methyl-6-tert-butylphenol) Monoethanolamine Molecular weight Propylene carbonate Polydimethylsiloxane Polyethylene glycol Poly(ethylene glycol) diacrylate Polyethylene oxide Poly(methylphenylsiloxane) Propylene oxide Poly(propylene glycol) Poly(propylene glycol) diacrylate Phase-transfer catalyst Poly(tetrahydrofuran) Polytetramethylene oxide Polyvinyl pyrrolidone... 

Pebax is a thermoplastic elastomer PA is an aliphatic polyamide hard block (e.g., nylon-6, nylon-12) and PEG is an amorphous polyether (polyethylene oxide (PEO) or polytetramethylene oxide (PTMO)) soft block (Scheme 4.2). 

Like PU TPE, blends of thermoplastic polyurethanes and polyamide-12 (PA-12) have been studied by Polosmak and co-workers [61]. They have mixed two types of thermoplastic polyurethane (TPU) based on oligoether (polytetramethylene oxide, molecular weight, 1000) and oligoester (polyethylene butylene glycol adipate, molecular weight, 2000) and PA 12 were characterised by IR spectra and thermal analysis. IR spectra of TPU, PA-12 and their blends show that in amide one (Al) carbonyl absorbancy is seen to split [55] into two main bands with maxima at 1705 and 1730 cm 1. At 1730 cm 1,... 

Materials. All monomers used for synthesis were free of inhibitors and freshly distilled 2-hydroxyethyl methacrylate (HEMA) dimethyl-acrylamide (DMA) N-vinylpyrrolidone (NPV) methylmethacrylate (MMA) 2-ethylhexylacrylate (EHA) isopropylmethacrylate (IPMA) n-butyl-acrylate (BA) ethyleneglycol-dimethacrylate (EGDMA) dimethacrylate macromer obtained by reaction of 1 mol polytetramethylene oxide diol (MW 2000) with 2 mol 2,4,4-trimethyl-l,6-diisocyanatohexane and 2 mol HEMA (PX). ... 

Typical DSC thermograms of segmented polyurethanes are shown in Figure 5 (43). The samples are based on MDI-BD hard segments combined with either polytetramethylene oxide (PTMO) or polytetra-methylene adipate (PTMA) as soft segment. The nomenclature has been established whereby the two figures following the ET (PTMO/ BD/MDI copolymer) or ES (PTMA/BD/MDI copolymer) indicate the... 

The equilibrium is shifted completely to the right. Thanks to the presence of the phenolate group at the chain ends, the macromolecules could be counted by UV spectrophotometry (polytetramethylene oxide is transparent in the UV range). With the counter-ion B = BF termination was slow with B- = AlCl it was rapid. The active centres can be counted using the Saegusa and Matsumoto method and, together with a determination of the degree of polymerization and the concentration of macromolecules, the elementary constants can be determined (the dead-stop method). 

Fig. 13. TXT cure diagram temperature of cure vs. the times to phase separation (doud point), gelation and vitrification for a neat and two rubber-modified systems. of the neat system is also included. The systems studied were DER331/TMAB O, gelation , vitrificaticm modified with IS parts rubber per hundred parts epoxy 1) pr eacted carboxyl-terminated butadiene-acrylonitrile (CTBN) copolymer containing 17% acrylonitrile (K-293, Spencer Kellog Co.) A, phase separation , gelation , vitrification, and 2) polytetramethylene oxide terminated with anmiatic amine (ODA2000, Polaroid Corp.) A. phase separation O, gelation O, vitrification. (DER331/TMAB/ K-293 data from Ref. )...

The polymerization of this 1,4 epoxide has been widely studied [115] and the polymer produced, polytetramethylene oxide or polytetrahydro-furan, has found commercial application. The most characteristic feature of the polymerization is the occurrence of a ceiling temperature within the range of normal laboratory experiments, 85°C. In any polymerization the propagation reaction is normally shown as a reaction going 100% to completion although in fact this reaction, and the other elementary steps, are really chemical equilibria. Some reactant, usually monomer in the case of propagation, is present at the end of the reaction although the value of the... 

The second technique for analyzing weight-loss data is illustrated in Figure 3 for an MDI-polytetramethylene oxide-butanediol polymer. The logarithm of the heating rate is plotted against the reciprocal of the temperature necessary to reach... 

Figure 1 shows stress-strain curves for the commercial polyether polyurethane and for PU-13, made from methane diphenyl dllsocyanate (MDI), butane diol (BD), and polytetramethylene oxide diol of molecular weight, 2000 (PTMO 2000). There is little difference in stress values for aged and imaged polymers. 

A comparison of the thermal stability of polyethylene oxide, polypropylene oxide, polyethylene and polypropylene has been presented by Madorsky and Straus [230]. More recently, studies on the thermal degradation of polytetramethylene oxide (I), polyhexamethylene oxide (II) and polydioxolane (III)... 

The effect of compatibilization of grafted or block copolymers as controllers of interphase interaction has been well known (1,28). Marosi and Bertlan (29), for example, described the compatibUizing effect of polybutylene terephthalate-polytetramethylene oxide block copolymers on PA6/HDPE blends. The addition of a block copolymer prevents separation in the blends during processing and increases the impact strength of the material several times. 

Nonabsorbable polyether-esters of polybutylene terephthalate and polytetramethylene oxide... 

Herbert, C. B., Hernandez, A. M. and Hubbel, J. A., Platelet adhesion to polyurethane blended with polytetramethylene oxide, Biotechnol. Bioeng., 52, 81, 1996. 

The index m in Eqs. [10.33] and [10.34] is a measure of ability of a liquid to mpture a physical network of elastomer. Table 10.13 presents the values of the m parameter obtained at 298K for swelling of PBU crosslinked polydiene urethane epoxide, PDUE, crosslinked elastomers of butadiene-nitiile mbbers SCN-40, SCN-26, SCN-18 and also for crosslinked polyether urethane, PEU, synthesized from polytetramethylene oxide diol having M. 1000. Dibutyl phthalate, DBP, and tributyl phosphate, TBP, were used. 

Prepolymers of polybutadiene diol (M. 2500), polytetramethylene oxide diol (M. 1400 and M. 2100), and prepolymer of polypropylene oxide diol (M. 1400) were used to obtain segmented elastomers SPU-1 to SPU-5. Prepolymers were prepared by reaction of appropriate diol with 2,4-toluene diisocyanate (2 moles per one mole of diol). Prepolymers of polytetramethylene oxide diol (elastomers SPU-1 and SPU-4) were cured by methylene-bis-o-chloroaniline, MOCA, or by mixture of MOCA and polytetramethylene oxide diol (SPU-2 and SPU-3). SPU-5 samples, prepared from prepolymer of polypropylene oxide diol, were cured by MOCA, and prepolymer of polybutadiene diol was cured by a mixture of MOCA and polytetramethylene oxide diol (SPU-6). Various concentrations of hard segments, Cj, in SPU were set by a ratio of mixture components and molecular weight of prepolymer (Table 10.14). Excess of NCO-groups was in the range 1.03-1.06 for SPU-1 to SPU-5 and 0.99 for SPU-6. All samples were cured at 80°C for 4 days. The... 

To further advance the knowledge on swelling of these systems, a study was conducted using elastomers with a limited phase separation. Polyurethanes were made by a two-step process. Polybutadiene diol (M. 2500) polytetramethylene oxide diol (M. 1400 and 2100) were used. Prepolymers were prepared by reaction of one mole of diol and two moles of 2,4-tolnene diisocyanate. Polypropylene glycol triol, Laprol 373 (M. 370) was... 

Flexible segment PEO (Polyethylene oxide). "Flexible segment PTMO (Polytetramethylene oxide). Rigid segment PA6 (Polyamide-6). 

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