scholarly journals Excellent Toughening of 2,6-Diaminopyridine Derived Poly (Urethane Urea) via Dynamic Cross-Linkages and Interfering with Hydrogen Bonding of Urea Groups from Partially Coordinated Ligands

Polymers ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1320 ◽  
Author(s):  
Sun ◽  
Guo ◽  
Zhang ◽  
Li ◽  
Liu ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Hydrogen Bonding ◽  
Thermoplastic Polyurethane ◽  
Tensile Tests ◽  
Ligand Interaction ◽  
Chain Flexibility ◽  
Pyridine Moiety ◽  
Hard Segments ◽  
Poly Propylene ◽  
Metal Ligand

Conventional approaches to synthesize thermoplastic polyurethane (TPU) with excellent robustness are limited by a competing relationship between soft and hard segments for tuning mechanical properties in terms of chain flexibility and micro-phase separation. Herein, we present a facile and effective way of simultaneously improving the tensile strength, elongation, and toughness by constructing dynamic cross-linkages from metal-ligand interaction between Zn2+ and pyridine moiety in backbone of poly(urethane urea) (PUU) derived from 2,6-diaminopyridine and poly(propylene glycol). It was found that a Zn2+/pyridine ratio of 1:4 is the most effective for improving robustness. Specifically, tensile strength, elongation, and toughness could be remarkably increased to 16.0 MPa, 1286%, and 89.3 MJ/m3 with 226%, 29%, and 185% increments compared to uncomplexed PUU, respectively. Results from UV-vis, Fourier transform infrared spectroscopy (FTIR), cyclic tensile tests, and stress relaxation reveal that metal-ligand interaction significantly interferes with the hydrogen bonding of urea groups, thus leading to weakening of stiffness. Furthermore, half of vacant ligands enable dynamic complexation during stretching, which consequently ensures constant noncovalent cross-linkages for constraining mutual chain sliding, contributing to simultaneous improvement of tensile strength, elongation, and toughness. This work provides a promising approach for designing TPU with excellent robustness.

Tensile properties of the FFF-processed thermoplastic polyurethane (TPU) elastomer

2021 ◽  
Author(s):  
Budi Arifvianto ◽  
Teguh Nur Iman ◽  
Benidiktus Tulung Prayoga ◽  
Rini Dharmastiti ◽  
Urip Agus Salim ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Low Cost ◽  
Thermoplastic Polyurethane ◽  
High Strength ◽  
Tensile Tests ◽  
Uniaxial Tensile ◽  
Fused Filament Fabrication ◽  
Raster Angle ◽  
Manufacturing Techniques

Abstract Fused filament fabrication (FFF) has become one of the most popular, practical, and low-cost additive manufacturing techniques for fabricating geometrically-complex thermoplastic polyurethane (TPU) elastomer. However, there are still some uncertainties concerning the relationship between several operating parameters applied in this technique and the mechanical properties of the processed material. In this research, the influences of extruder temperature and raster orientation on the mechanical properties of the FFF-processed TPU elastomer were studied. A series of uniaxial tensile tests was carried out to determine tensile strength, strain, and elastic modulus of TPU elastomer that had been printed with various extruder temperatures, i.e., 190–230 °C, and raster angles, i.e., 0–90°. Thermal and chemical characterizations were also conducted to support the analysis in this research. The results obviously showed the ductile and elastic characteristics of the FFF-processed TPU, with specific tensile strength and strain that could reach up to 39 MPa and 600%, respectively. The failure mechanisms operating on the FFF-processed TPU and the result of stress analysis by using the developed Mohr’s circle are also discussed in this paper. In conclusion, the extrusion temperature of 200 °C and raster angle of 0° could be preferred to be applied in the FFF process to achieve high strength and ductile TPU elastomer.

The Effect of Mixed Chain Extender on the Hydrogen Bonding, Thermal and Mechanical Properties of TPUs

2020 ◽  
Vol 1001 ◽  
pp. 16-21
Author(s):  
Ju Jie Sun ◽  
Hai Rui Wang ◽  
Lan Cao ◽  
Tridib K. Sinha
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Hydrogen Bonding ◽  
Thermoplastic Polyurethane ◽  
Chain Extender ◽  
Mixing Ratio ◽  
Thermal And Mechanical Properties ◽  
Elongation At Break ◽  
Chain Extenders ◽  
Hard Block

Chain extender plays a significant role in enhancing the final mechanical properties of thermoplastic polyurethane (TPUs) derived from polytetra methylene etherglycol (PTMG) and 4,4-diphenylmethane diisocyanate (MDI). In this research we focused on the effect that mixed chain extender of ethylene glycol (EG) and 1,4-butanediol (BDO) used has on the phase behavior and morphology of high hard block content TPUs. DSC, FTIR, and mechanical testing were mainly used to characterize the morphology and properties of the TPUs materials. Through this work we were able to show that mixed ratio of different chain extenders had dramatic effects on the properties of the TPUs. After mixing EG and BDO, the degree of hydrogen bonding, melting temperature, tensile strength, tear strength, and hardness of TPUs are all reduced, the glass transition temperature is increased. when the mixing ratio is 1: 1 , the elongation at break is increased to 672% . However, when the mixing ratio is n (EG): n (BDO) = 1: 2, the tensile strength is increased to 29.2 MPa, and the elongation at break is reduced to 353%.

Preparation of microporous thermoplastic polyurethane by low-temperature supercritical CO2 foaming

2016 ◽  
Vol 53 (2) ◽  
pp. 135-150 ◽  
Author(s):  
Chien-Chia Chu ◽  
Shu-Kai Yeh ◽  
Sheng-Ping Peng ◽  
Ting-Wei Kang ◽  
Wen-Jeng Guo ◽  
...  
Keyword(s):  
Polyurethane Foam ◽  
Supercritical Co2 ◽  
Thermoplastic Polyurethane ◽  
Saturation Temperature ◽  
Phenyl Isocyanate ◽  
Blowing Agent ◽  
Soft Segments ◽  
Hard Segments ◽  
Poly Propylene ◽  
Foam Production

Thermoplastic polyurethane possesses many special characteristics. Its flexibility, rigidity, and elasticity can be adjusted by controlling the ratio of soft segments to hard segments. Due to its versatile physical properties, thermoplastic polyurethane is commonly used in transportation, construction, and biomaterials. However, methods for thermoplastic polyurethane foam production using CO2 are still under investigation. We have previously prepared nanoporous thermoplastic polyurethane foam using commercially available thermoplastic polyurethane; however, in this study, thermoplastic polyurethane was synthesized using 4,4′-methylenebis(phenyl isocyanate), poly(propylene glycol) and 1,4-butanediol, without solvents, using a pre-polymer method. The properties of the synthesized thermoplastic polyurethane were characterized by Fourier transform infrared spectroscopy, thermal analysis, and their mechanical properties were measured. The synthesized thermoplastic polyurethane was foamed by batch foaming using supercritical CO2 as the blowing agent. The effect of saturation temperature and saturation time on the cell morphology of the thermoplastic polyurethane foam was examined.

scholarly journals Mechano-responsive hydrogen-bonding array of thermoplastic polyurethane elastomer captures both strength and self-healing

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Youngho Eom ◽  
Seon-Mi Kim ◽  
Minkyung Lee ◽  
Hyeonyeol Jeon ◽  
Jaeduk Park ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Thermoplastic Polyurethane ◽  
Healing Process ◽  
Polyurethane Elastomer ◽  
Self Healing ◽  
Static Mode ◽  
Soft Segments ◽  
Hard Segments ◽  
Thermoplastic Polyurethane Elastomer ◽  
Dynamic Exchange

AbstractSelf-repairable materials strive to emulate curable and resilient biological tissue; however, their performance is currently insufficient for commercialization purposes because mending and toughening are mutually exclusive. Herein, we report a carbonate-type thermoplastic polyurethane elastomer that self-heals at 35 °C and exhibits a tensile strength of 43 MPa; this elastomer is as strong as the soles used in footwear. Distinctively, it has abundant carbonyl groups in soft-segments and is fully amorphous with negligible phase separation due to poor hard-segment stacking. It operates in dual mechano-responsive mode through a reversible disorder-to-order transition of its hydrogen-bonding array; it heals when static and toughens when dynamic. In static mode, non-crystalline hard segments promote the dynamic exchange of disordered carbonyl hydrogen-bonds for self-healing. The amorphous phase forms stiff crystals when stretched through a transition that orders inter-chain hydrogen bonding. The phase and strain fully return to the pre-stressed state after release to repeat the healing process.

scholarly journals Biodegradable and Toughened Composite of Poly(Propylene Carbonate)/Thermoplastic Polyurethane (PPC/TPU): Effect of Hydrogen Bonding

2018 ◽  
Vol 19 (7) ◽  
pp. 2032 ◽  
Author(s):  
Dongmei Han ◽  
Guiji Chen ◽  
Min Xiao ◽  
Shuanjin Wang ◽  
Shou Chen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Propylene Carbonate ◽  
Thermoplastic Polyurethane ◽  
Tensile Tests ◽  
Mechanical Analysis ◽  
Scanning Calorimetry ◽  
Thermal Stabilities ◽  
Dynamic Mechanical ◽  
Brittle Ductile Transition ◽  
Poly Propylene

The blends of Poly(propylene carbonate) (PPC) and polyester-based thermoplastic polyurethane (TPU) were melt compounded in an internal mixer. The compatibility, thermal behaviors, mechanical properties and toughening mechanism of the blends were investigated using Fourier transform infrared spectra (FTIR), tensile tests, impact tests, differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and dynamic mechanical analysis technologies. FTIR and SEM examination reveal strong interfacial adhesion between PPC matrix and suspended TPU particles. Dynamic mechanical analyzer (DMA) characterize the glass transition temperature, secondary motion and low temperature properties. By the incorporation of TPU, the thermal stabilities are greatly enhanced and the mechanical properties are obviously improved for the PPC/TPU blends. Moreover, PPC/TPU blends exhibit a brittle-ductile transition with the addition of 20 wt % TPU. It is considered that the enhanced toughness results in the shear yielding occurred in both PPC matrix and TPU particles of the blends.

The Research of Poly Propylene Carbonate /Nano-SiO2 Composites

2014 ◽  
Vol 904 ◽  
pp. 74-77 ◽  
Author(s):  
Qu Li ◽  
Heng Wu ◽  
Si Yuan Xie ◽  
Jiao Sun ◽  
Xing Hai Liu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Tensile Strength ◽  
Glass Transition ◽  
Transition Temperature ◽  
Propylene Carbonate ◽  
Tensile Tests ◽  
Slight Improvement ◽  
Biodegradable Poly ◽  
Poly Propylene

Biodegradable poly (propylene carbonate) (PPC) composite with a slight improvement in the thermal stability and tensile strength was successfully prepared by incorporating a low content of nano-SiO2. Tensile tests demonstrate the better mechanical properties of the composites prepared in this study. The obtained composites increases sharply from 1.57Mpa to 12.04Mpa by incorporating 5wt% nano-SiO2. Furthermore, the composites show approximately 8°C higher glass transition temperature (Tg) than that of neat PPC.The Tdmax of composite with 5wt% of nano-SiO2 was about 40°C higher than that of neat PPC.

scholarly journals Mechano-responsive hydrogen-bonding array of thermoplastic polyurethane elastomer captures both strength and self-healing

2020 ◽  
Author(s):  
Youngho Eom ◽  
Seon-Mi Kim ◽  
Minkyung Lee ◽  
Hyeonyeol Jeon ◽  
Sung Yeon Hwang ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Thermoplastic Polyurethane ◽  
Healing Process ◽  
Polyurethane Elastomer ◽  
Self Healing ◽  
Static Mode ◽  
Soft Segments ◽  
Hard Segments ◽  
Thermoplastic Polyurethane Elastomer ◽  
Dynamic Exchange

Abstract Self-repairable materials strive to emulate curable and resilient biological tissue; however, their performance is currently insufficient for commercialization purposes because mending and toughening are mutually exclusive. Here, we report a carbonate-type thermoplastic polyurethane elastomer that self-heals at 35 °C and is as strong as footwear elastomers. This elastomer exhibits the highest tensile strength to date (43 MPa). Distinctively, it has abundant carbonyl groups in soft-segments and is fully amorphous with negligible phase separation due to poor hard-segment stacking. It operates in dual mechano-responsive mode through a reversible disorder-to-order transition of its hydrogen-bonding array; it heals when static and toughens when dynamic. In static mode, non-crystalline hard segments promote dynamic exchange of disordered carbonyl hydrogen-bonds for self-healing. The amorphous phase forms stiff crystals when stretched through a transition that orders inter-chain hydrogen bonding. The phase and strain fully return to the pre-stressed state after release to repeat healing process.

PEMANFAATAN GLISERIN DARI RESIDU GLISERIN SEBAGAI PLASTICIZER UNTUK PEMBUATAN BIOPLASTIK DENGAN BAHAN BAKU PATI BONGGOL PISANG KEPOK

2017 ◽  
Vol 5 (4) ◽  
pp. 26-32 ◽  
Author(s):  
Azaria Robiana ◽  
M. Yashin Nahar ◽  
Hamidah Harahap
Keyword(s):  
Tensile Strength ◽  
Hydrogen Bonding ◽  
Fatty Acid ◽  
Maximum Yield ◽  
Sem Analysis ◽  
Water Molecules ◽  
Banana Weevil ◽  
Gelatinization Temperature ◽  
Recharge Area ◽  
Maximum Quantity

Glycerin residue is waste oleochemical industry that still contain glycerin. To produce quality and maximum quantity of glycerin, then research the effect of pH acidification using phosphoric acid. Glycerin analysis includes the analysis of pH, Fatty Acid and Ester (FAE), and analysis of the levels of glycerin. The maximum yield obtained at pH acidification 2 is grading 91,60% glycerin and Fatty Acid and Ester (FAE) 3,63 meq/100 g. Glycerin obtained is used as a plasticizer in the manufacture of bioplastics. Manufacture of bioplastics using the method of pouring a solution with varying concentrations of starch banana weevil (5% w/v and 7% w/v), variations of the addition of glycerin (1 ml, 3 ml, 5 ml and 7 ml), and a variety of gelatinization temperature (60°C, 70°C, and 80°C). Analysis of bioplastics include FTIR testing, tensile strength that is supported by SEM analysis. The results obtained in the analysis of FTIR does not form a new cluster on bioplastics starch banana weevil, but only a shift in the recharge area only, it is due to the addition of O-H groups originating from water molecules that enter the polysaccharide through a mechanism gelatinitation that generates interaction hydrogen bonding strengthened. The maximum tensile strength of bioplastics produced at a concentration of starch 7% w/v, 1 ml glycerine and gelatinization temperature of 80°C is 3,430 MPa. While the tensile strength bioplastic decreased with increasing glycerin which can be shown from the results of SEM where there is a crack, indentations and lumps of starch insoluble.

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