Synthesis of a new degradable polyurethane elastomer containing polyacetal soft segments

Hashimoto, Tamotsu; Umehara, Akihiro; Urushisaki, Michio; Kodaira, Toshiyuki

doi:10.1002/pola.20138

Cited by 31 publications

(18 citation statements)

References 5 publications

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“…Hence, the reactants were azeotropically dried to remove water adsorbed on Pluronic® prior to oligomerization. Polyacetal formation between divinyl ether and hydroxy-terminated monomers is favorable even at mild temperature [31-33]. At around 40°C, the polymerization is completed within 1 h. However, we have reacted Pluronic® and DEGDVE overnight at 50°C to ensure a successful oligomerization because Pluronic® of molecular weight around 5000 may not be readily accessible for the oligomerization.…”

Section: Resultsmentioning

confidence: 99%

A novel thermosensitive polymer with pH-dependent degradation for drug delivery

et al. 2010

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A class of thermosensitive biodegradable multiblock copolymers with acid-labile acetal linkages were synthesized from Pluronic® triblock copolymers (Pluronic® P85 and P104) and di-(ethylene glycol) divinyl ether. The novel polymers were engineered to form thermogels at body temperature and degrade in acidic environment. The Pluronic®-based acid-labile polymers were characterized using nuclear magnetic resonance, gel permeation chromatography and differential scanning calorimetry. In vitro biocompatibility of the synthesized polymers was evaluated using MTT assay. The polymers showed reverse thermogelling behavior in water around body temperature. The solgel transition temperatures of the polymers synthesized from Pluronic® P85 and P104 were lowered from 70.3 to 30 o C and from 68.5 to 26.9 o C, respectively, when the synthesized polymers were compared with corresponding Pluronic® block copolymers at a concentration of 25 wt%. The hydrophobic dye solubilization confirmed the formation of polymeric micelles in the aqueous solution. The sizes of multiblock copolymer increased upon a temperature rise indicating that thermal gelation was mediated by micellar aggregation. The thermally driven hydrogels showed preferential polymer degradation at acidic pH. At pH 5.0 and 6.5, the release of 40 kDa fluorescein isothiocyanate -dextran (FITC-dextran) from the thermally formed hydrogels was completed within 2 and 9 days, respectively. However, FITC-dextran was continuously released up to 30 days at neutral pH. The mechanism of FITC-dextran release at pH 5.0 was mainly an acid-catalyzed degradation whereas both diffusion and pH-dependent degradation resulted in FITC-dextran release at pH 6.5. The novel polymers hold great potential as a pH-sensitive controlled drug delivery system due to their interesting phase transition behavior and biocompatibility.

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Section: Resultsmentioning

confidence: 99%

A novel thermosensitive polymer with pH-dependent degradation for drug delivery

et al. 2010

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“…Elidrissi and coworkers [16] reported the aminolysis of TPU in dimethyl formamide and toluene mixed solvent at 120 o C using butylamine as aminolysis reagent. Hashimoto and coworkers [26,27] report the synthesis of novel TPU based on poly(tetramethylene ether) glycol containing acetal linkages (PTMG-Acetal-PU). Moreover, acid-induced degradation process of the polymer to regenerate PTMG for chemical recycling was also established.…”

Section: Introductionmentioning

confidence: 99%

Chemical degradation of thermoplastic polyurethane for recycling polyether polyol

Wang

Chen

Chen³

et al. 2011

Fibers Polym

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Thermoplastic polyurethane, based on 4,4'-diphenylmethane diisocyanate and polyether polyol, was degraded by glycol and ethanolamine at 170 o C. Optimum conditions for the glycolysis of thermoplastic polyurethane were investigated by adjusting the ratio of polymer to degradation reagent, glycol to ethanolamine as well as the reaction temperature. The degradation reaction was conducted under nitrogen atmosphere and accelerated by catalysts such as lithium acetate, which was evidenced by lowering the degradation temperature as well as the amounts of degradation reagent. The decomposition products were completely separated into two layers. The upper liquid layer was a polyether polyol, which was characterized by gel permeation chromatography (GPC), nuclear magnetic resonance (NMR), infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). The present glycolysis procedure allows a simple recycling of the hydroxyl terminated polyol in pure form.

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“…After drying, three layered (w/o/w) type microcapsules were obtained which were characterized by a Hitachi High-Technologies S-4800 field emission scanning electron microscope (FE-SEM) and an Otsuka Electronics ELS-8000HW particle size analyzer. Degradable diol was prepared as shown in Scheme 2 [16]. In a flask, 50.00 g of 4-vinyloxybutan-1-ol (TCI, Japan) and 1.71 g of 1,4-butanediol (Wako Chemical, Japan) were dissolved in 200 mL of THF.…”

Section: Methodsmentioning

confidence: 99%

“…Thermally peelable PSAs composed of thermal acid generators (TAGs) and acid-degradable polyurethanes were also proposed [15]. The polyurethanes were obtained from diols which were degradable into acetaldehyde and 1,4-butanediol as shown in Scheme 1 [16]. The PSAs could be peeled off from substrates easily on heating at different temperatures, reflecting the thermal decomposition temperature of used TAGs [15].…”

Section: Introductionmentioning

confidence: 99%

Development of Pressure-Sensitive Adhesives Degradable on Ultrasonic Irradiation

Tachi

Suyama

2017

J. Photopol. Sci. Technol.

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We have developed novel pressure-sensitive adhesives (PSAs) which could be peeled off easily on ultrasonic irradiation as external stimuli. The PSAs were composed of aciddegradable polyurethanes and microcapsules containing a thermal acid generator (TAG). Three layered (w/o/w) type microcapsules containing a TAG were prepared by coacervation method. Generation of acid from the microcapsules and PSA layers on ultrasonic irradiation in water was confirmed by pH changes. Peel strength of PSAs containing the microcapsules decreased from 10 to 1 N/20mm on ultrasonic irradiation in water at 28 kHz for 20 min. The peel strength of PSAs containing the microcapsules was constant on heating up to 80 °C for 1 h, while that decreased on heating above 80 °C. These results suggest that acid was generated but kept in microcapsules on heating up to 80 °C, and the acid was released from microcapsules when PSAs were ultrasonic irradiated or heated above 80 °C.

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Synthesis of a new degradable polyurethane elastomer containing polyacetal soft segments

Cited by 31 publications

References 5 publications

A novel thermosensitive polymer with pH-dependent degradation for drug delivery

A novel thermosensitive polymer with pH-dependent degradation for drug delivery

Chemical degradation of thermoplastic polyurethane for recycling polyether polyol

Development of Pressure-Sensitive Adhesives Degradable on Ultrasonic Irradiation

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