Segmented block copolyesters using click chemistry

June, Stephen M.; Bissel, Philippe; Long, Timothy Edward

doi:10.1002/pola.26168

Cited by 19 publications

(12 citation statements)

References 42 publications

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“…The T g values obtained by DMA (Table ) are higher than those by DSC (Table ). In the DMA test, the sample was subject to cyclic loading, thereby the chains became flexible at a relatively higher temperature than with the DSC method . Figure b also indicates that the nature of the tan δ curves is controlled by the hard segment content of PUTs.…”

Section: Resultsmentioning

confidence: 98%

“…In the DMA test, the sample was subject to cyclic loading, thereby the chains became fl exible at a relatively higher temperature than with the DSC method. [ 52,53 ] Figure 7 b also indicates that the nature of the tan δ curves is controlled by the hard segment content of PUTs. The tan δ curves for PUT-3 and PUT-4, in which the hard segment content exceeds 50 wt%, show two tan δ peaks corresponding to the T g of the soft phase ( T g,s ) and hard phase ( T g,h ).…”

Section: Dmamentioning

confidence: 87%

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Synthesis, Morphology, and Properties of Polyurethane-triazoles by Click Chemistry

Wang

Guo

Ding

2015

Macromol. Chem. Phys.

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To explore the applications of click chemistry in polyurethane materials, a series of novel linear polyurethane-triazoles (PUTs) are prepared using the in situ click reaction of propargylterminated polyurethanes with 1,4-dibromobutane in the presence of sodium azide. The PUT structures are confi rmed by 1 H NMR, Fourier transform infrared (FTIR) spectroscopy, and elemental analysis, and the number-average molecular weights of PUTs range from (3.74-11.16) × 10 4 g mol −1 , determined by gel permeation chromatography. The triazole ring content is characterized and the effects of incorporating the triazole rings on the properties and morphologies of PUTs are examined. Because of the extra dipole-dipole interaction and hydrogen bonds of 1,4-disubstituted triazole in the hard segments, microphase separation of the PUTs is enhanced compared with conventional polyurethane extended with 1,4-butanediol. The tensile strengths of PUTs, from 21.8 to 39.0 MPa, are higher than conventional polytriazole elastomers, owing to the physical crosslinks formed by the hydrogen bonds in the PUTs. However, the thermal stability of the PUTs decreases as the hard segment content increases. regard to health hazards of the isocyanates used, and possible side or unwanted reactions, such as reaction with water or with preformed urethane groups. [6][7][8] Since the copper (I)-catalyzed azide-alkyne cycloaddition (CuAAC) "click reaction" was introduced by Sharpless [ 9 ] and Meldal [ 10 ] independently, it has become a useful tool for connecting polymer fragments to form linear, [11][12][13] star, [14][15][16] and dendrimer architectures, [17][18][19] because of its high effi ciency, regioselectivity and mild reaction conditions. Polymers constructed using regular triazole linkages through click polymerization of small diynes and bisazides, called polytriazoles, are very brittle and show poor processability. [20][21][22] To improve the polymer properties, researchers have inserted polyols, such as PEG [ 23,24 ] and PDMS [ 25,26 ] into the structure to obtain polytriazole elastomers. However, relatively low mechanical properties of these polytriazole elastomers have been observed even after chemical crosslinking. Side chain post-functionalization of PUs by click methodologies has also been reported. PUs with clickable side chain groups, such as

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Section: Resultsmentioning

confidence: 98%

Section: Dmamentioning

confidence: 87%

Synthesis, Morphology, and Properties of Polyurethane-triazoles by Click Chemistry

Wang

Guo

Ding

2015

Macromol. Chem. Phys.

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“…Moreover, there are large flat regions existed in the fish scale fractures when the plasticizer DOS was added [Figure (C)], which weaken the intermolecular hydrogen bonding interaction of hard domains. AFM provided a method to confirm the microphase‐separated nature of as‐prepared polytriazoles . Figure depicts the aggregation of hard domains as bright regions whereas the soft segment matrix as the darker features .…”

Section: Resultsmentioning

confidence: 99%

“…AFM provided a method to confirm the microphase-separated nature of as-prepared polytriazoles. 27 Figure 7 depicts the aggregation of hard domains as bright regions whereas the soft segment matrix as the darker features. 28 The bright regions are much more bigger in PTU compared with PT, implying an enhanced microphase-separated feature with the synergistic effect of urethane and triazole unit.…”

Section: Mechanical Propertiesmentioning

confidence: 99%

Polytriazoles based on alkyne terminated polybutadiene with and without urethane segments: Morphology and properties

Li¹,

Zhao³

et al. 2017

J of Applied Polymer Sci

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Alkyne terminated polybutadiene with urethane segments (PUPB), a well‐controlled macromolecule, is synthesized with a two‐step routine and characterized by 1H NMR, IR spectroscopy as well as gel permeation chromatograph. Alkyne terminated polybutadiene without urethane segments (PTPB) is also synthesized and characterized. The two alkyne terminated polybutadiene are cured to generate corresponding polytriazoles. It is found that the mechanical properties of PUPB based polytriazoles are superior to that of PTPB. The fractured surfaces of PTPB based polytriazoles exhibit smooth microstructures whereas PUPB based polytriazoles show the rough microstructures. The atomic force microscopy images reveal well‐established microphase‐separated morphology in polytriazoles with the promotion of urethane segments. Thus, the strong hydrogen bonding interaction existed in urethane has a remarkable effect on the morphology and then the mechanical properties of the as‐prepared polytriazoles. In addition, dioctyl sebacate can serve as an excellent plasticizer to PUPB based polytriazoles, lowering the glass transition temperature (Tg) and improving the ductility. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45178.

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“…Segmented copolymers are commonly comprised of a flexible soft segment (SS), such as polydimethylsiloxane (PDMS) or a polyether, and a covalently linked hard segment (HS) that contains sequences that are incompatible with the SS . Examples of commonly used highly polar HS structures include amides, urethanes, ureas, esters and imides . The ability of the HSs to self‐associate and form strong physical crosslinks through non‐covalent intermolecular interactions governs the extent of microphase separation and ultimately thermomechanical properties.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and characterization of poly(propylene glycol) polytrioxamide and poly(urea oxamide) segmented copolymers

Buckwalter

Hudson

Moore

et al. 2013

Polymer International

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This report describes the synthesis and characterization of unprecedented poly(propylene glycol) (PPG) polytrioxamide and poly(urea oxamide) (UOx) segmented copolymers containing monodisperse hard segments. Synthesis of the segmented copolymers relied on an efficient two‐step end‐capping sequence, which resulted in novel difunctional oxamic hydrazide‐terminated polyether oligomers. Polymerization with oxalyl chloride or 4,4′‐methylenebis(cyclohexyl isocyanate) provided the desired segmented copolymers displaying thermoplastic elastomeric behavior. Variable‐temperature Fourier transform infrared and 1H NMR spectroscopies confirmed the presence of hard segment structures and revealed ordered hydrogen bonding interactions with thermal dissociation profiles similar to those of polyurea and polyoxamide copolymer analogs. Dynamic mechanical analysis of PPG‐UOx exhibited a longer, rubbery plateau with increased moduli compared to PPG polyurea, and tensile analysis revealed a dramatic increase in copolymer toughness due to enhanced hydrogen bonding. A new step‐growth polymerization strategy is described that is capable of producing tunable hydrogen bonding segmented copolymer architectures. © 2013 Society of Chemical Industry

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Segmented block copolyesters using click chemistry

Cited by 19 publications

References 42 publications

Synthesis, Morphology, and Properties of Polyurethane-triazoles by Click Chemistry

Synthesis, Morphology, and Properties of Polyurethane-triazoles by Click Chemistry

Polytriazoles based on alkyne terminated polybutadiene with and without urethane segments: Morphology and properties

Synthesis and characterization of poly(propylene glycol) polytrioxamide and poly(urea oxamide) segmented copolymers

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