scholarly journals Construction of Mechanically Reinforced Thermoplastic Polyurethane from Carbon Dioxide-Based Poly(ether carbonate) Polyols via Coordination Cross-Linking

Polymers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2765
Author(s):  
Gaosheng Gu ◽  
Jincheng Dong ◽  
Zhongyu Duan ◽  
Binyuan Liu

Using carbon dioxide-based poly(propylene ether carbonate) diol (PPCD), isophorone diisocyanate (IPDI), dimethylolbutyric acid (DMBA), ferric chloride (FeCl3), and ethylene glycol (EG) as the main raw materials, a novel thermoplastic polyurethane (TPU) is prepared through coordination of FeCl3 and DMBA to obtain TPU containing coordination enhancement directly. The Fourier transform infrared spectroscopy, 1H NMR, gel permeation chromatography, UV−Vis spectroscopy, tensile testing, dynamic mechanical analysis, X-ray diffraction, differential scanning calorimetry, and thermogravimetric analysis were explored to characterize chemical structures and mechanical properties of as-prepared TPU. With the increasing addition of FeCl3, the tensile strength and modulus of TPU increase. Although the elongation at break decreases, it still maintains a high level. Dynamic mechanical analysis shows that the glass-transition temperature moves to a high temperature gradually along with the increasing addition of FeCl3. X-ray diffraction results indicate that TPUs reinforced with FeCl3 or not are amorphous polymers. That FeCl3 coordinates with DMBA first is an effective strategy of getting TPU, which is effective and convenient in the industry without the separation of intermediate products. This work confirms that such Lewis acids as FeCl3 can improve and adjust the properties of TPU contenting coordination structures with an in-situ reaction in a low addition amount, which expands their applications in industry and engineering areas.

2011 ◽  
Vol 12 (4) ◽  
pp. 1380-1386 ◽  
Author(s):  
Carmiña Gartner ◽  
Betty Lucy López ◽  
Ligia Sierra ◽  
Robert Graf ◽  
Hans W. Spiess ◽  
...  

2017 ◽  
Vol 8 (22) ◽  
pp. 3530-3538 ◽  
Author(s):  
Erlantz Lizundia ◽  
Vishalkumar A. Makwana ◽  
Aitor Larrañaga ◽  
José Luis Vilas ◽  
Michael P. Shaver

The novel biodegradable aromatic–aliphatic polyester, poly(2-(2-hydroxyethoxy)benzoate), was explored through thermal analysis, X-ray diffraction, dynamic mechanical analysis and comparative bio and catalysed degradation.


2000 ◽  
Vol 73 (5) ◽  
pp. 864-874 ◽  
Author(s):  
T. Murakami ◽  
S. Kohjiya ◽  
Y. Ikeda ◽  
H. Urakawa ◽  
K. Kajiwara

Abstract Three viologen-type poly(tetramethylene oxide) (PTMO) ionenes with chloride anions (PTVs) were synthesized by living cationic polymerization, whose molecular masses of PTMO segments between the viologen units were 6100, 9800 and 12000 g/mol. The PTV films were elastomers and possessed the microphase-separated structure consisting of three phases, i.e., PTMO amorphous phase, PTMO crystalline phase and ionic aggregated phase. The effect of ionic content, i.e., the effect of molecular mass between the ionic segments on the higher-order structure and properties of the PTV films were investigated by differential scanning calorimetry, dynamic mechanical analysis, wide-angle X-ray diffraction and small-angle X-ray scattering (SAXS) measurements. The lower the ionic content was, the smaller the amorphous PTMO phase became and the more the long range-ordered structure of PTMO crystals of lamellae was regularly formed. This crystalline part significantly influenced the dynamic mechanical properties. The distance between the ionic domains became larger with the increase of the PTMO segments. The scattering peaks attributed to the crystalline phases and ionic domains were detected by SAXS for the PTV films whose molecular masses of PTMO segments were 9800 and 12000 g/mol. The distance between the ionic domains was changed little before and after the melting of PTMO crystals of PTV films.


Author(s):  
Mateusz Gołdyn ◽  
Anna Komasa ◽  
Mateusz Pawlaczyk ◽  
Aneta Lewandowska ◽  
Elżbieta Bartoszak-Adamska

The study of various forms of pharmaceutical substances with specific physicochemical properties suitable for putting them on the market is one of the elements of research in the pharmaceutical industry. A large proportion of active pharmaceutical ingredients (APIs) occur in the salt form. The use of an acidic coformer with a given structure and a suitable pK a value towards purine alkaloids containing a basic imidazole N atom can lead to salt formation. In this work, 2,6-dihydroxybenzoic acid (26DHBA) was used for cocrystallization of theobromine (TBR) and caffeine (CAF). Two novel salts, namely, theobrominium 2,6-dihydroxybenzoate, C7H9N4O2 +·C7H5O4 − (I), and caffeinium 2,6-dihydroxybenzoate, C8H11N4O2 +·C7H5O4 − (II), were synthesized. Both salts were obtained independently by slow evaporation from solution, by neat grinding and also by microwave-assisted slurry cocrystallization. Powder X-ray diffraction measurements proved the formation of the new substances. Single-crystal X-ray diffraction studies confirmed proton transfer between the given alkaloid and 26DHBA, and the formation of N—H...O hydrogen bonds in both I and II. Unlike the caffeine cations in II, the theobromine cations in I are paired by noncovalent N—H...O=C interactions and a cyclic array is observed. As expected, the two hydroxy groups in the 26DHBA anion in both salts are involved in two intramolecular O—H...O hydrogen bonds. C—H...O and π–π interactions further stabilize the crystal structures of both compounds. Steady-state UV–Vis spectroscopy showed changes in the water solubility of xanthines after ionizable complex formation. The obtained salts I and II were also characterized by theoretical calculations, Fourier-transform IR spectroscopy (FT–IR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and elemental analysis.


Foods ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1295
Author(s):  
Laura O’Donoghue ◽  
Md. Haque ◽  
Sean Hogan ◽  
Fathima Laffir ◽  
James O’Mahony ◽  
...  

The α-relaxation temperatures (Tα), derived from the storage and loss moduli using dynamic mechanical analysis (DMA), were compared to methods for stickiness and glass transition determination for a selection of model whey protein concentrate (WPC) powders with varying protein contents. Glass transition temperatures (Tg) were determined using differential scanning calorimetry (DSC), and stickiness behavior was characterized using a fluidization technique. For the lower protein powders (WPC 20 and 35), the mechanical Tα determined from the storage modulus of the DMA (Tα onset) were in good agreement with the fluidization results, whereas for higher protein powders (WPC 50 and 65), the fluidization results compared better to the loss modulus results of the DMA (Tα peak). This study demonstrates that DMA has the potential to be a useful technique to complement stickiness characterization of dairy powders by providing an increased understanding of the mechanisms of stickiness.


2012 ◽  
Vol 466-467 ◽  
pp. 23-26
Author(s):  
Kun Yan Wang ◽  
Ying Ye ◽  
Xiao Qing Zhu ◽  
Feng Cao

The blends of poly(trimethylene terephthalate) (PTT) with ethylene-propylene-diene copolymer grafted with maleic anhydride (EPDM-g-MA) and organoclay(OMMT) were prepared by melt blending.The composites were characterized by dynamic mechanical analysis (DMA) and differential scanning calorimetry (DSC). The results suggest that the PTT is immiscible with EPDM-g-MA when OMMT was added to the blends. Strorage modulus of the PTT/EPDM-g-MA/OMMT are higher than those of pure PTT. The melting point of pure PTT and blends was almost constant. The crystallinity of the blends with OMMT were higher than that of pure PTT.


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