Polytetramethylene oxide polyurethanes

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. 

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,... 

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... 

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. 

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

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... 

Biomer (trade name of Ethicon, USA). Believed to be primarily a segmented block copolymer of polytetramethylene oxide (PTMO)/MDI/ethylene diamine. Available as either a 30 wt% solution or as an extruded grade. A new type is a copolymer of polyurethane with hydroxy-terminated polydimethyl siloxane (PDMS) (Fig. 13.15). 

PC PE PES PET PF PFA PI PMMA PP PPO PS PSO PTFE PTMT PU PVA PVAC PVC PVDC PVDF PVF TFE SAN SI TP TPX UF UHMWPE UPVC Polycarbonate Polyethylene Polyether sulfone Polyethylene terephthalate Phenol-formaldehyde Polyfluoro alkoxy Polyimide Polymethyl methacrylate Polypropylene Polyphenylene oxide Polystyrene Polysulfone Polytetrafluoroethylene Polytetramethylene terephthalate (thermoplastic polyester) Polyurethane Polyvinyl alcohol Polyvinyl acetate Polyvinyl chloride Polyvinyl idene chloride Polyvinylidene fluoride Polyvinyl fluoride Polytelrafluoroethylene Styrene-acrylonitrile Silicone Thermoplastic Elastomers Polymethylpentene Urea formaldehyde Ultrahigh-molecular-weight polyethylene Unplasticized polyvinyl chloride... 

Alcoholysis diacetate ester of polytetramefhylene ether + alkanol = polytetramethylene ether glycol (PTMEG) + alkanol acetate ester alkali metal oxide or alkaline earth metal oxide in the presence of hot methanol PTMEG is used to make polyesters, polyurethanes etc. complete conversion of diester. [86]... 

Polyurethanes are sensitive to strong acids, strong alkalis, aromatics, alcohols, hot water, hot moist air and saturated steam. The hydrolytic stability of polyurethanes in applications must be considered carefully. However, polyurethanes are resistant to weak acids, weak alkalis, ozone, oxygen, mineral grease, oils and petroleum. There are doubts for the oxidation stability of polytetramethylene ether glycol based polyurethanes. Polycarbonate urethane is a promising substitute with good oxidation stability. 

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