scholarly journals Morphology and Physicochemical Properties of Branched Polyurethane/Biopolymer Blends

Polymers ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 16 ◽  
Author(s):  
Joanna Brzeska ◽  
Agnieszka Tercjak ◽  
Wanda Sikorska ◽  
Marek Kowalczuk ◽  
Maria Rutkowska
Keyword(s):  
Thermal Stability ◽  
Water Drop ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
Elongation At Break ◽  
Force Microscopy ◽  
Atomic Force ◽  
Microscopy Images ◽  
Thermal Stability Of ◽  
Biopolymer Blends

The aim of this study is the analyze the structure of branched polyurethanes based on synthetic poly([R,S]-3-hydroxybutyrate) and their blends with biopolymers and montmorillonite. The properties which would predict the potential susceptibility of these materials to degradation are also estimated. Fourier-transform infrared spectroscopy with attenuated total reflection analysis shows that poly([d,l]-lactide) is on the surfaces of polyurethanes, whereas chitosan and starch are included inside the blend network. Atomic force microscopy images have shown that the surfaces of investigated samples are heterogenous with the formation of spherulites in case of pure polyurethanes. The presence of biopolymers in the blend reduced the crystallinity of polyurethanes. Thermal stability of blends of polyurethanes with poly([d,l]-lactide) and polysaccharides decreased in comparison to pure polyurethanes. Although the tensile strength is reduced after the blending of polyurethanes with biopolymers, the elongation at break increased, especially in the case of polyurethane/poly([d,l]-lactide) blends. The presence of polysaccharides in the obtained blends caused the significant reduction of contact angle after one minute from water drop immersion. This hydrophilizing effect is the highest when montmorillonite has been incorporated into the chitosan blend. The estimated properties of the obtained materials suggest their potential sensitivity on environmental conditions.

Influence of trisilanol isooctyl POSS content on the structure, morphology and rheological properties of thermoplastic polyurethane (TPU)

2020 ◽  
Vol 40 (9) ◽  
pp. 727-735
Author(s):  
Rudinei Fiorio ◽  
Chaitanya Danda ◽  
João Maia
Keyword(s):  
Thermal Stability ◽  
Rheological Properties ◽  
Thermoplastic Polyurethane ◽  
Reactive Extrusion ◽  
Strain Rates ◽  
Force Microscopy ◽  
Atomic Force ◽  
Extensional Strain ◽  
Oligomeric Silsesquioxane ◽  
Thermal Stability Of

AbstractIn this study, thermoplastic polyurethanes (TPUs) containing trisilanol isooctyl polyhedral oligomeric silsesquioxane (POSS), a reactive nanofiller, were synthesized and characterized rheologically and morphologically, and the effects of POSS content on the melt thermal stability of the TPUs are investigated. Samples containing 0, 0.23, 0.57, 1.14, and 2.23% (w/w) POSS were synthesized by reactive extrusion and characterized by Fourier transform infrared spectroscopy (FTIR), oscillatory and extensional rheometry, atomic force microscopy (AFM), and small- and wide-angle X-ray scattering (SAXS and WAXS, respectively). The rheological properties of molten TPU are time-dependent and the melt thermal stability of the TPU is maximal at 1.14% of POSS. The addition of 0.23 and 0.57% POSS promotes strain-hardening at low extensional strain rates (0.01 and 0.10 s−1), not affecting the extensional characteristics at higher strain rates. The addition of increasing amounts of POSS leads to the formation of POSS-rich clusters well dispersed in the TPU matrix. SAXS and WAXS results show that the POSS domains are amorphous and that POSS does not modify the crystalline structure of TPU. Therefore, this work indicates that synthesizing TPU in the presence of trisilanol isooctyl POSS can increase the melt thermal stability of the polymer, facilitating its processing.

A Novel Cell Co-Culture Method Utilizing Thermo-Responsive Surface

2007 ◽  
Vol 342-343 ◽  
pp. 221-224
Author(s):  
Jin Suk Bae ◽  
Ga Young Jun ◽  
Akihiko Kikuchi ◽  
Teruo Okano ◽  
Chang Hyun Ahn ◽  
...  
Keyword(s):  
Contact Angle ◽  
Electron Spectroscopy ◽  
Electron Beam Irradiation ◽  
Culture Method ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
Beam Irradiation ◽  
Cover Glass ◽  
Force Microscopy ◽  
Atomic Force

In this work, we developed a novel patterned co-culture method with thermo-responsive poly(N-isopropylacrylamide) (PIPAAm) and poly(N-ρ-vinylbenzyl-Ο-β-D-galactopyranosyl-(1→ 4)-D-gluconamide) (PVLA) inducing active hepatocyte attachment. Patterned graft of PIPAAm onto PS dishes was carried out by electron beam irradiation using cover-glass as a photomask. PVLA was only coated onto PIPAAm-ungrafted domain because of hydrated hydrophilic property of PIPAAm at below the LCST. Analysis by attenuated total reflection-Fourier transform infrared and electron spectroscopy for chemical analysis revealed that PIPAAm and PVLA were successfully grafted and coated on surfaces of PS dishes. PIPAAm-grafted surface exhibited decreasing contact angle by changing temperature from 37 to 20°C, while PVLA-coated PS and non-treated PS had negligible contact angle changes with temperature alternation. Atomic force microscopy (AFM) results showed that PIPAAm-grafted and PVLA-coated PS had smoother surfaces than that of ungrafted PS dishes. After culture for 12 hours, hepatocytes were well attached on PVLA-coated domain. Hepatocytes adherent on PIPAAm-grafted domain were detached by decreasing temperature. And then, fibroblasts were seeded onto PIPAAm pattern-grafted domain. Fibroblasts were only attached and spread onto PIPAAm-grafted domain. Co-cultured hepatocytes showed better differentiated function of albumin expression compared to homotypic hepatocyte culture

Combined in situ atomic force microscopy and infrared attenuated total reflection spectroelectrochemistry

The Analyst ◽  
2013 ◽  
Vol 138 (22) ◽  
pp. 6746 ◽  
Author(s):  
Daniel Neubauer ◽  
Jochen Scharpf ◽  
Alberto Pasquarelli ◽  
Boris Mizaikoff ◽  
Christine Kranz
Keyword(s):  
Atomic Force Microscopy ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
Force Microscopy ◽  
Atomic Force

scholarly journals Effect of Modification with Various Epoxide Compounds on Mechanical, Thermal, and Coating Properties of Epoxy Resin

2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Alaaddin Cerit ◽  
Mustafa Esen Marti ◽  
Ulku Soydal ◽  
Suheyla Kocaman ◽  
Gulnare Ahmetli
Keyword(s):  
Thermal Stability ◽  
Atomic Force Microscopy ◽  
Tensile Strength ◽  
Epoxy Resin ◽  
Curing Process ◽  
Coating Properties ◽  
Corrosive Media ◽  
Force Microscopy ◽  
Atomic Force ◽  
Thermal Stability Of

Epoxy resin (ER) was modified with four different epoxide compounds, 4,5-epoxy-4-methyl-pentane-2-on (EMP), 3-phenyl-1,2-epoxypropane (PhEP), 1-chloro-2,3-epoxy-5-(chloromethyl)-5-hexene (CEH), and a fatty acid glycidyl ester (FAGE), to improve its chemical and physical properties. The effects of the addition and amount of these modifiers on mechanical, thermal, and coating properties were investigated. Atomic force microscopy was used to observe the changes obtained with the modification. The influence of the modifying agents on the curing process was monitored through FTIR spectroscopy. The curing degrees of ER and modified ERs (M-ERs) were found to be over 91%. The results showed that tensile strength of ER improved till 30% (wt.) with addition of the modifier content. Modification with EMP and PhEP remarkably enhanced the thermal stability of ER to be highly resistant to the corrosive media.

Preparation, thermal conductivity, and thermal stability of flame retardant polyethylene with exfoliated MoS2/MxOy

2017 ◽  
Vol 41 (22) ◽  
pp. 13287-13292 ◽  
Author(s):  
Karolina Wenelska ◽  
Ewa Mijowska
Keyword(s):  
Electron Microscopy ◽  
Thermal Conductivity ◽  
Thermal Stability ◽  
Transmission Electron Microscopy ◽  
Raman Spectroscopy ◽  
Atomic Force Microscopy ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Thermal Stability Of

In this work, exfoliated molybdenum disulfide (MoS2) modified by a metal oxide (MoS2/MxOy) was prepared by a hydrothermal method and characterized by atomic force microscopy (AFM), Raman spectroscopy and transmission electron microscopy (TEM).

Thermal Stability of Nano-Crystalline Nickel Electrodeposited into Porous Alumina

2020 ◽  
Vol 299 ◽  
pp. 281-286 ◽  
Author(s):  
D.I. Tishkevich ◽  
A.I. Vorobjova ◽  
A.V. Trukhanov
Keyword(s):  
Thermal Stability ◽  
Porous Alumina ◽  
Thermodynamic Characteristics ◽  
X Ray Diffraction ◽  
Force Microscopy ◽  
Porous Alumina Template ◽  
Alumina Membranes ◽  
Atomic Force ◽  
Nano Crystalline ◽  
Thermal Stability Of

Through-pores alumina membranes of 50 μm thickness and 70 × 70 mm size have been fabricated to deposit Ni nanowires by electrochemical processing. Due to highly ordered microstructure of the membranes, the pores were filled by nanowires almost to 100%. The membrane nanowires composite morphology, structure and thermodynamic characteristics have been studied by scanning electron microscopy, atomic-force microscopy, X-ray diffraction and differential thermal analysis. The thermal stability of Ni nanowires into porous alumina template and whole composite was determined.

scholarly journals Comparison of Thermal Stability of Epitaxially Grown (La0.5Sr0.5)CoO3 and (La0.6Sr0.4)MnO3 Thin Films Deposited on Si Substrate

2010 ◽  
Vol 445 ◽  
pp. 160-163
Author(s):  
Shigeki Sawamura ◽  
Naonori Sakamoto ◽  
De Sheng Fu ◽  
Kazuo Shinozaki ◽  
Hisao Suzuki ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Thermal Stability ◽  
High Resistivity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Post Annealing ◽  
Thermal Stability Of

Thermal stability of bottom electrode thin films (La0.5Sr0.5)CoO3 (LSCO) and (La0.6Sr0.4)MnO3 (LSMO) were investigated. The crystallization and surface morphology of the heterostructure were characterized using x-ray diffraction and atomic force microscopy. Resistivity of the LSCO thin film was 25 cm. However, the resistivity of LSCO thin film increases sharply with annealing temperature. The LSMO thin film has high resistivity (100 mcm). The film does not decompose after thermal processing at 900 °C. To confirm thermal stability, we examined the effect of post annealing at various temperatures on the morphology and resistivity. Results showed that LSMO has higher thermal stability than that of LSCO.

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