Effects of a polymeric additive in a biomedical poly(ether urethaneurea)

Freij-Larsson, Christina; Kober, Maria; Wesslén, Bengt; Willquist, Eva; Tengvall, Pentti

doi:10.1002/app.1993.070490507

Cited by 11 publications

(3 citation statements)

References 19 publications

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“…12,24 Santowhite Powder was cent increased after sterilization. The same effect also reported by Wu et al 32 to be present in was observed when the irradiation dose and the Biomer as an effective inhibitor surface cracking.…”

Section: Resultsmentioning

confidence: 98%

“…23 by DSC may be attributed to the time scale of The additional relaxation peak in the tan d The EtO treatment seems to affect the additive, showing a decrease in the temperature of tan d curve at Ç 35ЊC exhibited by Biospan has been attributed to a polymethacrylate additive. 24 Other peak associated to it. studies of this additive have been reported.…”

Section: Resultsmentioning

confidence: 99%

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Physical and mechanical behavior of sterilized biomedical segmented polyurethanes

Abraham

Frontini

Cuadrado

1997

J. Appl. Polym. Sci.

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Changes in the physical and mechanical behavior induced by two sterilization methods, gamma irradiation and ethylene oxide, were determined on two commercial medical-grade segmented polyurethanes. The two materials have different chemical composition: one is an aromatic poly(ether urethane urea), Biospan TM , and the other an aliphatic ether-free polyurethane, Chronoflex TM . Properties before and after sterilization procedures were compared resulting in specific structural changes for each formulation. The thermal and mechanical properties were examined using differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), stress-strain measurements, and its hysteresis cycle. Molecular weight measurements were performed by gel permeation chromatography (GPC). Sterilized Biospan samples showed a decrease in the soft-segment glass transition temperature (T g ,s ) and an increase in the soft segment crystallization heat along the quenching process. Sterilized Chronoflex materials showed the opposite behavior. The hysteresis percent and residual strain percent increased after sterilization. The same effect was observed when irradiation dose and strain level increased. Surface analysis performed by scanning electron microscopy showed magnification of original surface defects after sterilization.

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Section: Resultsmentioning

confidence: 98%

Section: Resultsmentioning

confidence: 99%

Physical and mechanical behavior of sterilized biomedical segmented polyurethanes

Abraham

Frontini

Cuadrado

1997

J. Appl. Polym. Sci.

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“…In many of the applications where the excellent mechanical properties of PU are required, surface modification is expected to preserve the bulk properties. Indeed, the need to use a small amount of surface active compounds has been pointed out by Wesslén et al. ,, They have shown that the addition in small amounts (5% weight) of an amphiphilic polymer in polyurethanes and polyurethane ureas is sufficient to confer an amphiphilic nature to the material. These modifications keep the bulk properties unaltered.…”

Section: Introductionmentioning

confidence: 99%

Surface Mobility of Polyurethane Networks Containing Fluorinated Amphiphilic Reactive Additives

2002

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We created a model system made up of PU networks containing reactive surfactant additives in small amounts (<1%), brought in during the synthesis and able to reorient when changing the surrounding medium. The surfactants were made of fluorinated chains, sulfonamide kneecaps, and alkyl chains with a hydroxyl function able to react with the network isocyanates. The basic PU were made of a macrodiol, a diisocyanate and a triol (cross-linking agent). We were able to change their bulk glass transition easily and therefore their surface mobility by varying the respective ratios of diol and triol (a rubbery one, Tg ) -20 °C, and a glassy one, Tg ) 40 °C). The reactive surfactants were used to give a hydrophobic nature to the surface of PU networks when in contact with air. Several characterizations were performed, including wetting and dewetting measurements, to prove that less than 1 wt % of the fluorinated reactive additives is sufficient to confer a very hydrophobic nature to the network surface without changing its bulk properties. The influence of the network glass transition on the top surface reorganization was also investigated.

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Investigation on suitability of poly(urethaneimides) as biomaterials

Masiulanis

Całusiński

Marjański

et al. 1995

J of Applied Polymer Sci

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SYNOPSISThe mechanical properties of poly(urethaneimides) (PUI) were compared with known biomedical polyurethanes. The resistance of PUI to extraction with hexane and water and to sterilization with ethylene oxide or water vapor was stated. Water sorption and the permeability of water vapor, oxygen, and carbon dioxide through PUI foils were investigated. In blood compatibility, the PUI foils were similar to cellulose material Cuprophane, used in dialysis. Preliminary in uiuo testing of PUI implanted in rats indicated good biocompatibility of this polymer. 0 1995 John Wiley & Sons, Inc. I NTRODU CTI ONAmong all polymer materials used in medicine for implants, polyurethanes ( P U ) were found to be the materials causing the coagulation of thrombocytes and formation of blood clots in the smallest degree. To improve their hemocompatibility, the surface of polyurethane products was modified by applying hydrophilic poly ( ethyleneoxide ) , sometimes bound to heparin, a natural mucopolysaccharide, which is an agent counteracting coagulation of blood.' The biolization method was also used, based on seeding on the polyurethane surface a layer of antithrombogenic endothelium cells containing the hormone prostaglandin, which has an inhibiting effect on the process of thrombocyte aggregation. The prostaglandine BW 245C analog also exhibited such an effect. ' Another method of polymer hemotolerance improvement is the modification of their surface by introducing hydrophilic poly ( N-vinylpyrolidone ) , used, e.g., in the case of p~lymethylmethacrylate~ and polysiloxane implant^.^ In view of the occurrence of the cyclic imide sys-

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Effects of a polymeric additive in a biomedical poly(ether urethaneurea)

Cited by 11 publications

References 19 publications

Physical and mechanical behavior of sterilized biomedical segmented polyurethanes

Physical and mechanical behavior of sterilized biomedical segmented polyurethanes

Surface Mobility of Polyurethane Networks Containing Fluorinated Amphiphilic Reactive Additives

Investigation on suitability of poly(urethaneimides) as biomaterials

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