Transparent thermoplastic polyurethanes based on aliphatic diisocyanates and polycarbonate diol

2016 ◽  
Vol 49 (1) ◽  
pp. 77-95 ◽  
Author(s):  
Clara Maria Gomez ◽  
D Gutierrez ◽  
M Asensio ◽  
V Costa ◽  
A Nohales
Keyword(s):  
Tensile Properties ◽  
Soft Segment ◽  
Mechanical Analysis ◽  
Attenuated Total Reflection ◽  
Hexamethylene Diisocyanate ◽  
Scanning Calorimetry ◽  
Phase Mixing ◽  
Thermoplastic Polyurethanes ◽  
Polycarbonate Diol ◽  
Weather Resistance

Segmented thermoplastic polyurethanes (PUs) were synthetized using polycarbonate diol as soft segment with a molar mass of 500 and as a hard segment 1,5-pentanediol with a combination of isophorone diisocyanate (IPDI) and hexamethylene diisocyanate (HDI). Differential scanning calorimetry, differential mechanical analysis, Fourier transform infrared-attenuated total reflection spectroscopy, haze, transmittance, hardness, tensile properties and retention of tensile properties tests were employed to characterize the different PUs. The results of this study show that IPDI/HDI relation has a significant impact on the phase mixing, crystallinity and therefore on the PU’s properties. The variation of diisocyanate type ratio allows obtaining PUs of different nature from a high rubbery material with a high content in IPDI to high crystalline PU increasing the HDI content. Material transparency was also modified by decreasing the amorphous nature of the materials with the increase in the HDI content. The weather resistance of the final PU is related with the different isocyanate relation.

scholarly journals Tunable Structure and Properties of Segmented Thermoplastic Polyurethanes as a Function of Flexible Segment

Polymers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 1910 ◽  
Author(s):  
Manuel Asensio ◽  
Victor Costa ◽  
Andrés Nohales ◽  
Otávio Bianchi ◽  
Clara M Gómez
Keyword(s):  
Tensile Properties ◽  
Microphase Separation ◽  
Mechanical Analysis ◽  
Phase Behaviour ◽  
Scanning Calorimetry ◽  
Thermoplastic Polyurethanes ◽  
Separation Degree ◽  
Tunable Structure ◽  
Flexible Segment ◽  
The Stability

Segmented thermoplastic polyurethanes (PUs) were synthetized using macrodiols with different functional groups (carbonate, ester, and /or ether) as a segment with a molar mass of 1000 and 2000 g/mol, and 4,4’-diphenylmethane diisocyanate (MDI) and 1,4-butanediol as a rigid segment. The polyurethanes obtained reveal a wide variation of microphase separation degree that is correlated with mechanical properties and retention of tensile properties under degradation by heat, oil, weather, and water. Different techniques such as differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), Fourier transform infrared (FTIR), and synchrotron small-angle X-ray scattering (SAXS) were used to determine rigid-flexible segments’ phase behaviour. Retention of tensile properties determines the stability of the samples under different external factors. This work reveals that pure polycarbonate-based macrodiols induce the highest degree of phase miscibility, better tensile properties, hardness shore A, and retention of tensile properties under external agents.

scholarly journals Shape memory polyurethanes based on recycled polyvinyl butyral. I. Synthesis and morphology

2013 ◽  
Vol 11 (12) ◽  
pp. 2058-2065 ◽  
Author(s):  
Tsvetomir Tsonev ◽  
Michael Herzog ◽  
Sanchi Nenkova
Keyword(s):  
Shape Memory ◽  
Hard Segment ◽  
Soft Segment ◽  
Polyvinyl Butyral ◽  
Mechanical Analysis ◽  
Attenuated Total Reflection ◽  
Polypropylene Glycol ◽  
Scanning Calorimetry ◽  
Chemical Crosslinks ◽  
Physical And Chemical

AbstractShape memory polyurethanes (SMPUs) were synthesized by 4,4′-diphenylmethane diisocyanate (MDI), hexane-1,6-diol (HD), polypropylene glycol (PPG), and recycled polyvinyl butyral (PVB). Dynamic mechanical analysis, differential scanning calorimetry and Fourier transformation infrared attenuated total reflection spectroscopy was used to characterize the poly (vinylbutyral-urethanes). Micro-phase domain separation of hard and soft segments and phase inversion were investigated. Increasing the hard segment content, i.e., average hard segment molecular weight, leads to an increase in the degree of micro-phase separation, hard domain order and crystallinity. The crystalline hard segment structures combined with the elastic nature of soft segment matrix provide enough physical and chemical crosslinks to have shape memory effect.

scholarly journals Preparation, Thermal, and Thermo-Mechanical Characterization of Polymeric Blends Based on Di(meth)acrylate Monomers

Polymers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 878
Author(s):  
Krystyna Wnuczek ◽  
Andrzej Puszka ◽  
Łukasz Klapiszewski ◽  
Beata Podkościelna
Keyword(s):  
Mechanical Analysis ◽  
Attenuated Total Reflection ◽  
Scanning Calorimetry ◽  
Force Microscopy ◽  
Chemical Structures ◽  
Atomic Force ◽  
Polymeric Blends ◽  
Ft Ir ◽  
Acrylate Monomers ◽  
Synthesized Materials

This study presents the preparation and the thermo-mechanical characteristics of polymeric blends based on di(meth)acrylates monomers. Bisphenol A glycerolate diacrylate (BPA.GDA) or ethylene glycol dimethacrylate (EGDMA) were used as crosslinking monomers. Methyl methacrylate (MMA) was used as an active solvent in both copolymerization approaches. Commercial polycarbonate (PC) was used as a modifying soluble additive. The preparation of blends and method of polymerization by using UV initiator (Irqacure® 651) was proposed. Two parallel sets of MMA-based materials were obtained. The first included more harmless linear hydrocarbons (EGDMA + MMA), whereas the second included the usually used aromatic copolymers (BPA.GDA + MMA). The influence of different amounts of PC on the physicochemical properties was discussed in detail. Chemical structures of the copolymers were confirmed by attenuated total reflection–Fourier transform infrared (ATR/FT-IR) spectroscopy. Thermo-mechanical properties of the synthesized materials were investigated by means of differential scanning calorimetry (DSC), thermogravimetric (TG/DTG) analyses, and dynamic mechanical analysis (DMA). The hardness of the obtained materials was also tested. In order to evaluate the surface of the materials, their images were obtained with the use of atomic force microscopy (AFM).

scholarly journals Medical-Grade PCL Based Polyurethane System for FDM 3D Printing—Characterization and Fabrication

Materials ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 887 ◽  
Author(s):  
Agnieszka Haryńska ◽  
Justyna Kucinska-Lipka ◽  
Agnieszka Sulowska ◽  
Iga Gubanska ◽  
Marcin Kostrzewa ◽  
...  
Keyword(s):  
3D Printing ◽  
Fused Deposition Modeling ◽  
Extrusion Process ◽  
C2c12 Cells ◽  
Hexamethylene Diisocyanate ◽  
Scanning Calorimetry ◽  
Thermoplastic Polyurethanes ◽  
Fused Deposition ◽  
Medical Grade

The widespread use of three-dimensional (3D) printing technologies in medicine has contributed to the increased demand for 3D printing materials. In addition, new printing materials that are appearing in the industry do not provide a detailed material characterization. In this paper, we present the synthesis and characterization of polycaprolactone (PCL) based medical-grade thermoplastic polyurethanes, which are suitable for forming in a filament that is dedicated to Fused Deposition Modeling 3D (FDM 3D)printers. For this purpose, we synthesized polyurethane that is based on PCL and 1,6-hexamethylene diisocyanate (HDI) with a different isocyanate index NCO:OH (0.9:1, 1.1:1). Particular characteristics of synthesized materials included, structural properties (FTIR, Raman), thermal (differential scanning calorimetry (DSC), thermogravimetric analysis (TGA)), mechanical and surfaces (contact angle) properties. Moreover, pre-biological tests in vitro and degradation studies were also performed. On the basis of the conducted tests, a material with more desirable properties S-TPU(PCL)0.9 was selected and the optimization of filament forming via melt-extrusion process was described. The initial biological test showed the biocompatibility of synthesized S-TPU(PCL)0.9 with respect to C2C12 cells. It was noticed that the process of thermoplastic polyurethanes (TPU) filaments forming by extrusion was significantly influenced by the appropriate ratio between the temperature profile, rotation speed, and dosage ratio.

REACTION KINETICS OF HEXAMETHYLENE DIISOCYANATE AND POLYPROPYLENE GLYCOLS

2014 ◽  
Vol 87 (4) ◽  
pp. 617-628
Author(s):  
Min-Tzung Ye ◽  
Shinn-Gwo Hong
Keyword(s):  
Reaction Kinetics ◽  
Frequency Factor ◽  
Mechanical Analysis ◽  
Hexamethylene Diisocyanate ◽  
Empirical Equations ◽  
Ozawa Method ◽  
Scanning Calorimetry ◽  
Isothermal Reaction ◽  
Molecular Weights ◽  
Kinetics Of

ABSTRACT The kinetics of the reaction between hexamethylene diisocyanate (HDI) and polypropylene glycols (PPG) of different molecular weights toward the synthesis of polyurethanes with versatile properties was studied using differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA). From the dynamic exotherms observed in DSC, it was found that the Kissinger equation modified by an additional temperature term in its frequency factor term was able to accurately describe the isothermal reaction kinetics of all HDI/PPG reactions. The modification can be justified by analyses with the Ozawa method and the modulus observed under DMA measurements. Regardless of the type of PPG used, the frequency factors changed with respect to the degree of conversion and maximized at near 70% conversion. The derivation of the modified kinetic equation is presented. In addition, the empirical equations describing the dependence of the activation energies and frequency factors on the molecular weights of PPG were also derived.

scholarly journals Fibrillation of flax and wheat straw cellulose: Effects on thermal, morphological, and viscoelastic properties of poly(vinylalcohol)/fibre composites

BioResources ◽  
2011 ◽  
Vol 6 (2) ◽  
pp. 1631-1647 ◽  
Author(s):  
Marta Hrabalova ◽  
Manfred Schwanninger ◽  
Rupert Wimmer ◽  
Adriana Gregorova ◽  
Tanja Zimmermann ◽  
...  
Keyword(s):  
High Pressure ◽  
Polyvinyl Alcohol ◽  
Wheat Straw ◽  
Composite Films ◽  
Fibre Diameter ◽  
Mechanical Analysis ◽  
Degree Of Polymerization ◽  
Attenuated Total Reflection ◽  
Scanning Calorimetry ◽  
Cellulose Material

Nano-fibrillated cellulose was produced from flax and wheat straw cellulose pulps by high pressure disintegration. The reinforcing potential of both disintegrated nano-celluloses in a polyvinyl-alcohol matrix was evaluated. Disintegration of wheat straw was significantly more time and energy consuming. Disintegration did not lead to distinct changes in the degree of polymerization; however, the fibre diameter reduction was more than a hundredfold, creating a nano-fibrillated cellulose network, as shown through field-emission-scanning electron microscopy. Composite films were prepared from polyvinyl alcohol and filled with nano-fibrillated celluloses up to 40% mass fractions. Nano-fibrillated flax showed better dispersion in the polyvinyl alcohol matrix, compared to nano-fibrillated wheat straw. Dynamic mechanical analysis of composites revealed that the glass transition and rubbery region increased more strongly with included flax nano-fibrils. Intermolecular interactions between cellulose fibrils and polyvinyl alcohol matrix were shown through differential scanning calorimetry and attenuated total reflection-Fourier transform infrared spectroscopy. The selection of appropriate raw cellulose material for high pressure disintegration was an indispensable factor for the processing of nano-fibrillated cellulose, which is essential for the functional optimization of products.

Synthesis and Characterization of IPDI Based Shape Memory Polyurethane

2020 ◽  
Vol 1010 ◽  
pp. 142-147
Author(s):  
Nur Athirah Rasli @ Rosli ◽  
Syazana Ahmad Zubir
Keyword(s):  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Soft Segment ◽  
Shape Memory Polymer ◽  
Palm Kernel ◽  
Hexamethylene Diisocyanate ◽  
Molar Ratio ◽  
Scanning Calorimetry ◽  
Chain Flexibility

Various polyurethane-based shape memory polymer was synthesized using polycaprolactone (PCL) as soft segment and, hexamethylene diisocyanate (HMDI) and isophorone diisocyanate (IPDI) as the hard segments. Palm kernel oil-based polyol was used to replace part of the petroleum-based polyol due to the increasing demand on renewable resources as a result of environmental awareness. The synthesis has been carried out using two step polymerization method. The effects of varying the molar ratio of IPDI/HMDI on material properties such as crystallinity, transition temperature, morphology, shape memory effect and tensile strength were investigated by using Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), X-ray diffraction (XRD), scanning electron microscopy (SEM), shape memory test and tensile test. A high IPDI content in SMPU results in better shape memory effect, whereas increasing HMDI content leads to a better chain flexibility. In this work, the incorporation of IPDI contributes to the formation of phase separation which enhance the formation of crystalline soft segment structure while the incorporation of HMDI as isocyanate tend to promote phase mixing which enhance the chain flexibility of the SMPU backbone.

Polycarbonate-based polyurethane elastomers: temperature-dependence of tensile properties

2014 ◽  
Vol 68 (2) ◽  
Author(s):  
Zdeněk Hrdlička ◽  
Antonín Kuta ◽  
Rafał Poręba ◽  
Milena Špírková
Keyword(s):  
Tensile Properties ◽  
Hard Segment ◽  
Elevated Temperatures ◽  
Thermoplastic Elastomers ◽  
Chain Extender ◽  
Hexamethylene Diisocyanate ◽  
Polyurethane Elastomers ◽  
Oh Groups ◽  
Polycarbonate Diol ◽  
Polyurethane Composition

AbstractNovel polyurethane thermoplastic elastomers were prepared from polycarbonate diols, butane-1,4-diol (chain extender) and hexamethylene diisocyanate. They differ in the kind of macrodiol used and the ratio of macrodiol to chain extender OH groups (hence, in hard segment contents). The tensile properties of the elastomers at low and elevated temperatures were determined and discussed with regard to polyurethane composition and polycarbonate diol structure.

Controlling stereocomplexation, heat resistance and mechanical properties of stereocomplex polylactide films by using mixtures of low and high molecular weight poly(D-lactide)s

e-Polymers ◽  
2018 ◽  
Vol 18 (6) ◽  
pp. 485-490 ◽  
Author(s):  
Yaowalak Srisuwan ◽  
Yodthong Baimark
Keyword(s):  
Mechanical Properties ◽  
Molecular Weight ◽  
Heat Resistance ◽  
Tensile Properties ◽  
Tensile Testing ◽  
Mechanical Analysis ◽  
Scanning Calorimetry ◽  
Molecular Weights ◽  
Film Series ◽  
High Molecular Weight Poly

AbstractStereocomplex polylactide (scPLA) films were prepared by blending poly(L-lactide) (PLLA) and poly(D-lactide) (PDLA) solutions before solvent evaporation. The PLLA/PDLA ratios were 80/20 and 60/40 (w/w). PDLAs with low and high molecular weights (M.W.) were used as PDLA mixtures. The scPLA films with different low/high M.W. PDLA ratios were investigated for both the 80/20 and 60/40 (w/w) scPLA film series. Stereocomplexation, heat resistance and the mechanical properties of the scPLA films were studied by differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA) and tensile testing, respectively. The results indicated that low M.W. PDLA can enhance the stereocomplexation and heat resistance of scPLA films while the high M.W. PDLA can improve tensile properties of scPLA films. It was concluded that the stereocomplexation, heat resistance and tensile properties of scPLA films could be controlled by adjusting the low/high M.W. PDLA ratio in PDLA fraction.

scholarly journals Mechanically Robust Hybrid POSS Thermoplastic Polyurethanes with Enhanced Surface Hydrophobicity

Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 373 ◽  
Author(s):  
Xiuhuan Song ◽  
Xiaoxiao Zhang ◽  
Tianduo Li ◽  
Zibiao Li ◽  
Hong Chi
Keyword(s):  
High Performance ◽  
Mechanical Performance ◽  
Loss Modulus ◽  
Surface Hydrophobicity ◽  
Hexamethylene Diisocyanate ◽  
Scanning Calorimetry ◽  
Hybrid Filler ◽  
Remarkable Effect ◽  
Thermoplastic Polyurethanes ◽  
Static Contact

A series of hybrid thermoplastic polyurethanes (PUs) were synthesized from bi-functional polyhedral oligomeric silsesquioxane (B-POSS) and polycaprolactone (PCL) using 1,6-hexamethylene diisocyanate (HDI) as a coupling agent for the first time. The newly synthesized hybrid materials were fully characterized in terms of structure, morphology, thermal and mechanical performance, as well as their toughening effect toward polyesters. Thermal gravimeter analysis (TGA) and differential scanning calorimetry (DSC) showed enhanced thermal stability by 76 °C higher in decomposition temperature (Td) of the POSS PUs, and 22 °C higher glass transition temperature (Tg) when compared with control PU without POSS. Static contact angle results showed a significant increment of 49.8° and 53.4° for the respective surface hydrophobicity and lipophilicity measurements. More importantly, both storage modulus (G’) and loss modulus (G’’) are improved in the hybrid POSS PUs and these parameters can be further adjusted by varying POSS content in the copolymer. As a biodegradable hybrid filler, the as-synthesized POSS PUs also demonstrated a remarkable effect in toughening commercial polyesters, indicating a simple yet useful strategy in developing high-performance polyester for advanced biomedical applications.

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