The Experts below are selected from a list of 1977 Experts worldwide ranked by ideXlab platform
Andrew P Dove - One of the best experts on this subject based on the ideXlab platform.
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application of functional diols derived from pentaerythritol as chain extenders in the synthesis of novel Thermoplastic Polyester urethane elastomers
Polymer Chemistry, 2019Co-Authors: Ruairi P Brannigan, Anthony J Walder, Andrew P DoveAbstract:The success of Thermoplastic elastomers is owed to the wide range of thermal, mechanical and degradation properties that enable them to be tuned to myriad applications. In large, this is achieved through the manipulation of the chemical structure of their component parts e.g. polyol, diisocyanate and diol chain extender. The permutation of diol extenders is of great interest industrially owing to their commercial availability and ease of synthesis and purification, however, the incorporation of extenders with post-polymerisation modifiable sites, specifically moieties prone to ‘click’ coupling chemistries has been relatively overlooked until recent times. Herein, the application of ‘acetal-diols’, (2-phenyl-1,3-dioxane-5,5-diyl)dimethanol (CPh) and (2-(norbornene)-1,3-dioxane-5,5-diyl)dimethanol (CNb), as extenders in the synthesis of novel Thermoplastic polyurethanes (TPUs) is described. The assessment of their structure–property relationship reveals that the material properties are highly tailorable based on their urethane content. Furthermore, norbornene ‘click’ chemistries could be utilised post-polymerisation as a method of manipulating the materials’ hydrophilicity and degradability.
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application of modified amino acid derived diols as chain extenders in the synthesis of novel Thermoplastic Polyester urethane elastomers
ACS Sustainable Chemistry & Engineering, 2017Co-Authors: Ruairi P Brannigan, Anthony J Walder, Andrew P DoveAbstract:Owing to their robust processability and mechanical dexterity, Thermoplastic polyurethanes (TPUs) have been utilized in a wide variety of applications from commodity to more niche biomedical applications. Despite this, the focus on deriving monomers from sustainable resources has been relatively low; however, bioderived diisocyanates, diamine/diol chain extenders, and Polyester-based polyols have all been studied. Herein we report the application of biorenewable diol chain extenders derived from amino acids using an organocatalyzed process in bulk. To determine the effect of extender chain length on the properties of the resultant materials, TPEUs were synthesized using diol extenders derived from amino acids, 1-(1,3-dihydroxypropan-2-yl)-3-ethylurea (C3u), 1-(1,4-dihydroxybutan-2-yl)-4-ethylurea (C4u), and 1-(1,5-dihydroxypentan-2-yl)-5-ethylurea (C5u). When poly(e-caprolactone) (PCL) and 1-isocyanato-4-[(4-isocyanatocyclohexyl) methyl]cyclohexane (H12MDI) were used as the polyol and diisocyanate, respec...
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Application of Modified Amino Acid-Derived Diols as Chain Extenders in the Synthesis of Novel Thermoplastic Polyester–Urethane Elastomers
2017Co-Authors: Ruairi P Brannigan, Anthony Walder, Andrew P DoveAbstract:Owing to their robust processability and mechanical dexterity, Thermoplastic polyurethanes (TPUs) have been utilized in a wide variety of applications from commodity to more niche biomedical applications. Despite this, the focus on deriving monomers from sustainable resources has been relatively low; however, bioderived diisocyanates, diamine/diol chain extenders, and Polyester-based polyols have all been studied. Herein we report the application of biorenewable diol chain extenders derived from amino acids using an organocatalyzed process in bulk. To determine the effect of extender chain length on the properties of the resultant materials, TPEUs were synthesized using diol extenders derived from amino acids, 1-(1,3-dihydroxypropan-2-yl)-3-ethylurea (C3u), 1-(1,4-dihydroxybutan-2-yl)-4-ethylurea (C4u), and 1-(1,5-dihydroxypentan-2-yl)-5-ethylurea (C5u). When poly(ε-caprolactone) (PCL) and 1-isocyanato-4-[(4-isocyanatocyclohexyl) methyl]cyclohexane (H12MDI) were used as the polyol and diisocyanate, respectively, TPEUs were synthesized yielding materials with a predetermined percentage “hard segment” (%HS) and molecular weight. It was established through the selection of extender chain length and by controlling the %HS, that both the thermal and mechanical properties of the TPEUs could be controlled. Furthermore, the extender chain length was found to affect both the hydrophilicity and hydrolytic degradation profile of the resultant materials
Ruairi P Brannigan - One of the best experts on this subject based on the ideXlab platform.
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application of functional diols derived from pentaerythritol as chain extenders in the synthesis of novel Thermoplastic Polyester urethane elastomers
Polymer Chemistry, 2019Co-Authors: Ruairi P Brannigan, Anthony J Walder, Andrew P DoveAbstract:The success of Thermoplastic elastomers is owed to the wide range of thermal, mechanical and degradation properties that enable them to be tuned to myriad applications. In large, this is achieved through the manipulation of the chemical structure of their component parts e.g. polyol, diisocyanate and diol chain extender. The permutation of diol extenders is of great interest industrially owing to their commercial availability and ease of synthesis and purification, however, the incorporation of extenders with post-polymerisation modifiable sites, specifically moieties prone to ‘click’ coupling chemistries has been relatively overlooked until recent times. Herein, the application of ‘acetal-diols’, (2-phenyl-1,3-dioxane-5,5-diyl)dimethanol (CPh) and (2-(norbornene)-1,3-dioxane-5,5-diyl)dimethanol (CNb), as extenders in the synthesis of novel Thermoplastic polyurethanes (TPUs) is described. The assessment of their structure–property relationship reveals that the material properties are highly tailorable based on their urethane content. Furthermore, norbornene ‘click’ chemistries could be utilised post-polymerisation as a method of manipulating the materials’ hydrophilicity and degradability.
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application of modified amino acid derived diols as chain extenders in the synthesis of novel Thermoplastic Polyester urethane elastomers
ACS Sustainable Chemistry & Engineering, 2017Co-Authors: Ruairi P Brannigan, Anthony J Walder, Andrew P DoveAbstract:Owing to their robust processability and mechanical dexterity, Thermoplastic polyurethanes (TPUs) have been utilized in a wide variety of applications from commodity to more niche biomedical applications. Despite this, the focus on deriving monomers from sustainable resources has been relatively low; however, bioderived diisocyanates, diamine/diol chain extenders, and Polyester-based polyols have all been studied. Herein we report the application of biorenewable diol chain extenders derived from amino acids using an organocatalyzed process in bulk. To determine the effect of extender chain length on the properties of the resultant materials, TPEUs were synthesized using diol extenders derived from amino acids, 1-(1,3-dihydroxypropan-2-yl)-3-ethylurea (C3u), 1-(1,4-dihydroxybutan-2-yl)-4-ethylurea (C4u), and 1-(1,5-dihydroxypentan-2-yl)-5-ethylurea (C5u). When poly(e-caprolactone) (PCL) and 1-isocyanato-4-[(4-isocyanatocyclohexyl) methyl]cyclohexane (H12MDI) were used as the polyol and diisocyanate, respec...
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Application of Modified Amino Acid-Derived Diols as Chain Extenders in the Synthesis of Novel Thermoplastic Polyester–Urethane Elastomers
2017Co-Authors: Ruairi P Brannigan, Anthony Walder, Andrew P DoveAbstract:Owing to their robust processability and mechanical dexterity, Thermoplastic polyurethanes (TPUs) have been utilized in a wide variety of applications from commodity to more niche biomedical applications. Despite this, the focus on deriving monomers from sustainable resources has been relatively low; however, bioderived diisocyanates, diamine/diol chain extenders, and Polyester-based polyols have all been studied. Herein we report the application of biorenewable diol chain extenders derived from amino acids using an organocatalyzed process in bulk. To determine the effect of extender chain length on the properties of the resultant materials, TPEUs were synthesized using diol extenders derived from amino acids, 1-(1,3-dihydroxypropan-2-yl)-3-ethylurea (C3u), 1-(1,4-dihydroxybutan-2-yl)-4-ethylurea (C4u), and 1-(1,5-dihydroxypentan-2-yl)-5-ethylurea (C5u). When poly(ε-caprolactone) (PCL) and 1-isocyanato-4-[(4-isocyanatocyclohexyl) methyl]cyclohexane (H12MDI) were used as the polyol and diisocyanate, respectively, TPEUs were synthesized yielding materials with a predetermined percentage “hard segment” (%HS) and molecular weight. It was established through the selection of extender chain length and by controlling the %HS, that both the thermal and mechanical properties of the TPEUs could be controlled. Furthermore, the extender chain length was found to affect both the hydrophilicity and hydrolytic degradation profile of the resultant materials
Chul B Park - One of the best experts on this subject based on the ideXlab platform.
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poly lactic acid foaming
Progress in Polymer Science, 2014Co-Authors: Mohammadreza Nofar, Chul B ParkAbstract:Abstract Poly (lactic acid) or polylactide (PLA) is an aliphatic Thermoplastic Polyester produced from renewable resources and is compostable in the environment. Because of the massive use of foamed products of petroleum-based polymers, PLA foams have been considered as substitutes for some of these products. Specifically, because of PLA's competitive material and processing costs, and its comparable mechanical properties, PLA foams could potentially replace polystyrene (PS) foam products in a wide array of applications such as packaging, cushioning, construction, thermal and sound insulation, and plastic utensils. Due to their biocompatibility, PLA foams can also be used in such biomedical applications as scaffolding and tissue engineering. But PLA has several inherent drawbacks, which inhibit the production of low-density foams with uniform cell morphology. These drawbacks are mainly the PLA's low melt strength and its slow crystallization kinetics. During the last two decades, researchers have investigated the fundamentals of PLA/gas mixtures, PLA foaming mechanisms, and the effects of material modification on PLA's foaming behavior through various manufacturing technologies. This article reviews these investigations and compares the developments made thus far in PLA foaming.
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poly lactic acid crystallization
Progress in Polymer Science, 2012Co-Authors: Sajjad Saeidlou, Michel A Huneault, Hongbo Li, Chul B ParkAbstract:Abstract Poly(lactic acid) is a biobased and compostable Thermoplastic Polyester that has rapidly evolved into a competitive commodity material over the last decade. One key bottleneck in extending the use of PLA is the control of its crystallinity. Understanding the crystallization behavior is particularly crucial to control PLA's degradation rate, thermal resistance as well as optical, mechanical and barrier properties. PLA crystallization has also been a particularly rich topic from a fundamental point of view because of the existence of the two enantiomeric forms of lactic acid that can be used to control the crystallization rate but also to form high melting point stereocomplex structures. This article presents an overview of the current understanding on the fundamentals of PLA crystallization in quiescent conditions and on the practical means to enhance its rate. Data from the abundant literature on PLA crystallization were compiled and analyzed to provide comprehensive relationships between crystallization kinetics and the main molecular structure characteristics of PLA. In addition, the most promising efforts in enhancing PLA crystallization kinetics through plasticization or heterogeneous nucleation were reviewed.
Anthony J Walder - One of the best experts on this subject based on the ideXlab platform.
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application of functional diols derived from pentaerythritol as chain extenders in the synthesis of novel Thermoplastic Polyester urethane elastomers
Polymer Chemistry, 2019Co-Authors: Ruairi P Brannigan, Anthony J Walder, Andrew P DoveAbstract:The success of Thermoplastic elastomers is owed to the wide range of thermal, mechanical and degradation properties that enable them to be tuned to myriad applications. In large, this is achieved through the manipulation of the chemical structure of their component parts e.g. polyol, diisocyanate and diol chain extender. The permutation of diol extenders is of great interest industrially owing to their commercial availability and ease of synthesis and purification, however, the incorporation of extenders with post-polymerisation modifiable sites, specifically moieties prone to ‘click’ coupling chemistries has been relatively overlooked until recent times. Herein, the application of ‘acetal-diols’, (2-phenyl-1,3-dioxane-5,5-diyl)dimethanol (CPh) and (2-(norbornene)-1,3-dioxane-5,5-diyl)dimethanol (CNb), as extenders in the synthesis of novel Thermoplastic polyurethanes (TPUs) is described. The assessment of their structure–property relationship reveals that the material properties are highly tailorable based on their urethane content. Furthermore, norbornene ‘click’ chemistries could be utilised post-polymerisation as a method of manipulating the materials’ hydrophilicity and degradability.
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application of modified amino acid derived diols as chain extenders in the synthesis of novel Thermoplastic Polyester urethane elastomers
ACS Sustainable Chemistry & Engineering, 2017Co-Authors: Ruairi P Brannigan, Anthony J Walder, Andrew P DoveAbstract:Owing to their robust processability and mechanical dexterity, Thermoplastic polyurethanes (TPUs) have been utilized in a wide variety of applications from commodity to more niche biomedical applications. Despite this, the focus on deriving monomers from sustainable resources has been relatively low; however, bioderived diisocyanates, diamine/diol chain extenders, and Polyester-based polyols have all been studied. Herein we report the application of biorenewable diol chain extenders derived from amino acids using an organocatalyzed process in bulk. To determine the effect of extender chain length on the properties of the resultant materials, TPEUs were synthesized using diol extenders derived from amino acids, 1-(1,3-dihydroxypropan-2-yl)-3-ethylurea (C3u), 1-(1,4-dihydroxybutan-2-yl)-4-ethylurea (C4u), and 1-(1,5-dihydroxypentan-2-yl)-5-ethylurea (C5u). When poly(e-caprolactone) (PCL) and 1-isocyanato-4-[(4-isocyanatocyclohexyl) methyl]cyclohexane (H12MDI) were used as the polyol and diisocyanate, respec...
Qinghong Fang - One of the best experts on this subject based on the ideXlab platform.
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synthesis and characterization of biobased Thermoplastic Polyester elastomers containing poly butylene 2 5 furandicarboxylate
RSC Advances, 2021Co-Authors: Hailan Kang, Xiaoli Miao, Qinghong FangAbstract:A series of sustainable and reprocessible Thermoplastic Polyester elastomers P(BF-PBSS)s were synthesized using dimethyl-2,5-furandicarboxylate, 1,4-butanediol, and synthetic low-molecular-weight biobased Polyester (PBSS). The P(BF-PBSS)s contain poly(butylene 2,5-furandicarboxylate) (PBF) as their hard segment and PBSS as their soft segment. The microstructures of the P(BF-PBSS)s were confirmed by nuclear magnetic resonance, demonstrating that a higher content of the soft segment was incorporated into P(BF-PBSS)s with higher PBSS content. Interestingly, dynamic mechanical analysis indicated that P(BF-PBSS)s comprised two domains: crystalline PBF and a mixture of amorphous PBF and PBSS. Consequently, the microphase separations of P(BF-PBSS)s were mainly induced by the crystallization of their PBF segments. More importantly, the thermal, crystallization, and mechanical properties could be tailored by tuning the PBSS content. Our results indicate that the as-prepared P(BF-PBSS)s are renewable, thermally stable, and nontoxic, and have good tensile properties, indicating that they could be potentially applied in biomedical materials.
