Grafting of Triphenylmethyl Group onto Polyurethane and the Impact on the Shape Recovery and Flexibility at Extremely Low Temperature

Chung, Yong‐Chan; Kim, Sang Hyeon; Bae, Jin Cheol; Chun, Byoung Chul

doi:10.1007/s12221-018-8082-6

Cited by 8 publications

(10 citation statements)

References 21 publications

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“…Recovery was complete below 0°C for all of the tetracycline‐attached samples whether polyol or DMPA was included or not. Previously, notable flexibility at freezing temperature came from the disruption of interaction between hard segments by attached rigid tetracycline as observed in the PUs with rigid attached groups . Therefore, the tested PU samples proved outstanding low‐temperature flexibility together with high tensile strength and reliable shape recovering capability to original form.…”

Section: Resultsmentioning

confidence: 94%

“…[14][15][16] Functional groups were frequently attached to PU using an attachment method via allophanate bonding due to the convenience and effectiveness of one step process. 17,18 Some of the functionalization examples of PU include blood compatibility, 19 microbial activity, 20 low temperature flexibility, 21 pH sensitivity, 22 and electric conductivity. 23 In addition, a complete suppression of fungal growth on PU was observed by the attached benzimidazole if hydrophilic groups were simultaneously attached to PU surface.…”

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confidence: 99%

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The effect of attached tetracycline and hydrophilic groups on the enhancement of antibacterial effectiveness and low temperature flexibility of polyurethane

Chung

Kim

Choi

et al. 2019

Polymers for Advanced Techs

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Tetracycline was chemically attached to polyurethane (PU) to enhance its antimicrobial activity, and a carboxyl group or polyol was also attached to PU to enhance the hydrophilicity. The attached groups affected cross‐linking, viscosity of PU solution, glass transition of soft segment, breaking tensile stress, reliable shape recovery capability, flexibility at very low temperature, surface hydrophilicity, and antibacterial effectiveness. The glass transition temperature could go up from −67.5°C for unmodified PU to −48.8°C due to the attached tetracycline. The attachment of tetracycline boosted breaking tensile stress and shape recovery by 345% and 186%, respectively, relative to unmodified PU. The attached carboxyl group and polyol improved the hydrophilicity as confirmed by water swelling and water contact angle data. Finally, PU samples with the attached tetracycline demonstrated excellent flexibility at freezing temperature compared with ordinary PU and absolutely inhibited the bacterial growth of S. aureus and K. pneumoniae on PU.

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Section: Resultsmentioning

confidence: 94%

mentioning

confidence: 99%

The effect of attached tetracycline and hydrophilic groups on the enhancement of antibacterial effectiveness and low temperature flexibility of polyurethane

Chung

Kim

Choi

et al. 2019

Polymers for Advanced Techs

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“…A small portion of the grafted poly(IPA) can be linked to other grafted poly(IPA), as shown in Scheme c, which is confirmed by crosslink density and significantly influence tensile and shape memory properties. Swelling of PU in toluene is proportionally restricted by the progress of crosslinking, and the relationship is the basis for measurement of crosslink density via the Flory–Rehner method . The crosslink density of the IPA series increases slightly with the increase of IPA monomer content, but that of the CIPA series does not increase at all compared with L (Fig.…”

Section: Resultsmentioning

confidence: 99%

“…Crosslink density is determined to confirm the feasibility of crosslinking between PUs using the method of polymer swelling in toluene, as explained in previous studies . The change in contact angle of a water drop (2 μL) is monitored for 600 s to determine the water compatibility of PU surface using a contact shape analyzer (Krűss DSA 100, Hamburg, Germany).…”

Section: Methodsmentioning

confidence: 99%

“…The PU surface has been modified via a grafting method to enhance its hydrophilicity , biocompatibility , antimicrobial activity , antifungal activity , electric conductivity , and flexibility at freezing temperature . The grafting of poly(IPA) to PU can be accomplished by the graft‐polymerization method in which a repeated array of N‐isopropyl groups can be attached to PU.…”

Section: Introductionmentioning

confidence: 99%

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Preparation and characterization of hydrophilic temperature‐dependent polyurethane containing the grafted poly(N‐isopropylacrylamide)

Chung

Bae

Choi

et al. 2019

Polymer Engineering & Sci

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The polyurethane (PU) structure is modified with dimethylolpropionic acid (DMPA) and poly(N‐isopropylacrylamide; poly[IPA]) to prepare hydrophilic temperature‐dependent PU that is investigated with reference to the degree of crosslinking, thermal properties of soft segment, tensile and shape memory performance, hydrophilic conversion of surface, and temperature‐dependent water swelling and water vapor permeability (WVP). The thermal properties of soft segment (melting, crystallization, and glass transition) are significantly affected by poly(IPA). Breaking tensile stress also increases with increasing IPA monomer content due to crosslinking effect but breaking tensile strain does not significantly decrease with increasing IPA monomer content. Shape recovery capability at 10°C steeply inclines to over 90% from 46.9% for unmodified PU by the grafting of poly(IPA), whereas shape retention at −25°C does not decrease below 90% with the increase in IPA content. Poly(IPA)‐grafted PU can display temperature‐dependent control of water swelling and WVP due to transformation of the grafted poly(IPA) depending on the surrounding temperature. POLYM. ENG. SCI., 59:1719–1728 2019. © 2019 Society of Plastics Engineers

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The reinforcing effect of cyclic binary secondary amine chain extenders on the cryogenic performance of thermoplastic polyurethane elastomers

Geng

Wang

et al. 2022

J of Applied Polymer Sci

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The poor cryogenic performance of thermoplastic polyurethanes (TPU) severely restricts their extensive application in low‐temperature fields as elastomers. Chain extenders are one of the adjustable items for TPUs to optimize cryogenic performance. In this contribution, three cyclic amine homologs of imidazoline, piperazine and 2‐methylpiperazine are selected as bi‐functional chain extenders. The corresponding TPU elastomers, TPU‐IM, TPU‐PP, and TPU‐2P with identical soft segments, are synthesized by the prepolymer method. All TPUs' structure, morphology and thermodynamic properties were investigated. The results showed that the cyclic amine structure embedded in TPU hard segment can effectively promote microphase separation through hydrogen‐bonded crosslink and polar aggregation on the molecular scale, achieving a glass transition temperature (Tg) as low as −103.9°C for resisting low temperatures. The mechanical properties also demonstrated a 23‐fold improvement compared to the control TPU‐BD. The elastomer TPU‐PP possessed the best all‐around performance with an ideal Tg of −98.4°C and tensile strength of 18.1 MPa. We believe that these TPUs will have potential applications in cryogenic engineering.

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Grafting of Triphenylmethyl Group onto Polyurethane and the Impact on the Shape Recovery and Flexibility at Extremely Low Temperature

Cited by 8 publications

References 21 publications

The effect of attached tetracycline and hydrophilic groups on the enhancement of antibacterial effectiveness and low temperature flexibility of polyurethane

The effect of attached tetracycline and hydrophilic groups on the enhancement of antibacterial effectiveness and low temperature flexibility of polyurethane

Preparation and characterization of hydrophilic temperature‐dependent polyurethane containing the grafted poly(N‐isopropylacrylamide)

The reinforcing effect of cyclic binary secondary amine chain extenders on the cryogenic performance of thermoplastic polyurethane elastomers

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