scholarly journals Influence of Polyol/Crosslinker Blend Composition on Phase Separation and Thermo-Mechanical Properties of Polyurethane Thin Films

Polymers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 666 ◽  
Author(s):  
Said Arévalo-Alquichire ◽  
Maria Morales-Gonzalez ◽  
Kelly Navas-Gómez ◽  
Luis E. Diaz ◽  
José A. Gómez-Tejedor ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Phase Separation ◽  
Loss Factor ◽  
Microphase Separation ◽  
Mechanical Analysis ◽  
Damping Capacity ◽  
Force Microscopy ◽  
X Ray Scattering ◽  
Atomic Force ◽  
Hard Segments

Polyurethanes (PUs) from Polyethylene glycol (PEG) and polycaprolactone diol (PCL) and a crosslinker, Pentaerythritol (PE), were synthetized with isophorone diisocyanate (IPDI). In this study, we investigated the effect of polyol and crosslinker composition on phase separation and thermo-mechanical properties. The properties were studied through dynamic mechanical analysis, X-ray scattering, atomic force microscopy (AFM), and thermogravimetric analysis (TGA). The results showed changes in PUs properties, microphase structure, and separation due to the composition of polyol/crosslinker blend. So, the largest concentration of PE produced multimodal loss factor patterns, indicating segment segregation while PUs with a PEG/PCL = 1 displayed a monomodal loss factor pattern, indicating a homogeneously distributed microphase separation. Additionally, the increase of the PEG concentration enhanced the damping capacity. On the other hand, agglomeration and thread-like structures of hard segments (HS) were observed through AFM. Finally, the thermal behavior of PUs was affected by chemical composition. Lower concentration of PE reduced the crosslinking; hence, the temperature with the maximum degradation rate.

scholarly journals Study on the morphology and thermomechanical properties of poly(urethane-siloxane) networks based on hyperbranched polyester

2013 ◽  
Vol 67 (6) ◽  
pp. 871-879
Author(s):  
Marija Pergal ◽  
Jasna Dzunuzovic ◽  
Milena Spírková ◽  
Rafal Poręba ◽  
Milos Steinhart ◽  
...  
Keyword(s):  
Ethylene Oxide ◽  
Microphase Separation ◽  
Soft Segment ◽  
Hydrophobic Surface ◽  
Crosslinking Density ◽  
Thermomechanical Properties ◽  
Hyperbranched Polyester ◽  
Force Microscopy ◽  
X Ray Scattering ◽  
Atomic Force

Two series of polyurethane films based on hyperbranched polyester of the second pseudogeneration (Boltorn?), 4,4'-methylenediphenyl diisocyanate and two different siloxane prepolymers, ?,?-dihydroxy-(ethylene oxide-poly(dimethylsiloxane)-ethylene oxide) (EO-PDMS-EO) and ?,?-dihydroxypropyl-poly(dimethylsiloxane) (HP-PDMS), were prepared by two-step polymerization in solution. The influence of the type and content of soft segment on the morphology, thermomechanical and surface properties of the synthesized polyurethanes was studied by atomic force microscopy (AFM), small-angle X-ray scattering (SAXS), scanning electron microscopy (SEM), dynamic mechanical thermal analysis (DMTA) and water absorption measurements. It was found that these techniques confirmed existence of microphase separated morphology. Synthesized polyurethanes exhibited two glass transition temperatures and one second relaxation process. The results showed that polyurethanes based on HP-PDMS had higher surface roughness, better microphase separation and waterproof performances. Samples synthesized with lower PDMS content had less hydrophobic surface, but higher crosslinking density and better thermomechanical properties. (Projekat Ministarstva nauke Republike Srbije, br. 172062]

Effect of thermal processing temperature on the microphase separation and mechanical properties of BAMO/THF polyurethane

2017 ◽  
Vol 37 (2) ◽  
pp. 169-176 ◽  
Author(s):  
Jian Xiaoxia ◽  
Hu Yiwen ◽  
Zheng Qilong
Keyword(s):  
Mechanical Properties ◽  
Hydrogen Bonding ◽  
Thermal Processing ◽  
Microphase Separation ◽  
Mechanical Analysis ◽  
Processing Temperature ◽  
X Ray ◽  
X Ray Scattering ◽  
Bonding Phase ◽  
And Storage

Abstract This paper describes the influence of thermal processing temperature on the microphase separation, hydrogen bonding, phase transitions and mechanical properties of 3,3-bis(azidomethyl)oxetane (BAMO)/tetrahydrofuran (THF) polyurethane binder, which is used for propellant. Fourier transform infrared (FTIR) spectroscopy confirmed that the intended polyurethane was synthesized and was used to determine the state of the local hydrogen bonding in these polyurethanes. The results showed that the thermal processing clearly imparts significant changes to the H-bonded environment and this was confirmed in a quantitative fashion using small-angle X-ray scattering (SAXS). The dynamic mechanical analysis (DMA) revealed rather significant changes in dynamic segmental relaxations and storage moduli for this series of BAMO/THF polyurethanes, which are in keeping with the findings from other experiments.

Synthesis, Characterization and Mechanical Properties of Hydroxyl-Terminated Hyperbranched Polymer Graft Polyether-Based Aliphatic Polyurethane Elastomer

2010 ◽  
Vol 152-153 ◽  
pp. 525-529
Author(s):  
Tao Tao Qiang ◽  
Xue Chuan Wang ◽  
Xian Bo Lu ◽  
Long Fang Ren
Keyword(s):  
Mechanical Properties ◽  
Microphase Separation ◽  
Testing Machine ◽  
Film Surface ◽  
Dibutyltin Dilaurate ◽  
Polyurethane Elastomer ◽  
Force Microscopy ◽  
Atomic Force ◽  
Hyperbranched Poly ◽  
Ft Ir

Hydroxyl-terminated hyperbranched polyurethane elastomer (HBPU) was synthesized by graft copolymerization of hyperbranched poly (amine-ester) polyols(HPAE) and polyether-based aliphatic polyurethane prepolymer(PPU), and the PPU was synthesized by step polymerization of isophorone diisocyanate(IPDI) with polyethylene glycol(PEG) and dibutyltin dilaurate(DBTDL) as catalyst. The FT-IR spectroscopy, TGA and XRD were used to characterize the structure, thermal properties and crystallinity of HBPU. The mechanical properties of the elastomers were conducted on a testing machine. Microphase separation of HBPU film surface was studied by atomic force microscopy (AFM). The experimental results showed that the HBPU took on excellent hydrogen bonding and mechanical properties. The tensile strength of HBPU elastomer reached to 20.6MPa, which increased by 41.2 times than that of PPU elastomer. And the elongation at break was as high as 251.3%.

Study on Morphology and Mechanical Properties of Polyaspartic Esters Based Polyureas

2011 ◽  
Vol 197-198 ◽  
pp. 1289-1293
Author(s):  
Wei Bo Huang ◽  
Ping Lu ◽  
Jing Zhang ◽  
Xin Mao Li
Keyword(s):  
Mechanical Properties ◽  
Microphase Separation ◽  
Dynamic Mechanical Properties ◽  
Mechanical Analysis ◽  
Hexamethylene Diisocyanate ◽  
Shock Absorption ◽  
Dynamic Mechanical ◽  
Atomic Force ◽  
Weight Test ◽  
Drop Weight Test

The morphology, shock absorption and dynamic mechanical properties of a new architectured multifunctional materials- polyaspartic esters (PAE) based ployureas were investigated through FTIR, atomic force microscope(AFM), drop-weight test and dynamic mechanical analysis(DMA). The PAE based polyureas were prepared from synthesized PAE and hexamethylene diisocyanate（HDI）trimer /polytetramethylene ether glycol (PTMG) prepolymer. The FTIR results indicated that hydrogen-bonded urea carbonyl of PAE based polyurea was 76.1%, and the length of hydrogen bonding was 0.306nm. The microphase separation phenomenon of the PAE based polyureas were observed directly through AFM topography studies. PAE based polyureas exhibited unique shock absorption and dynamic mechanical properties.

Mechanical Properties of Membrane Surface of Cultured Astrocyte Revealed by Atomic Force Microscopy

2000 ◽  
Vol 39 (Part 1, No. 6B) ◽  
pp. 3711-3716 ◽  
Author(s):  
Hatsuki Shiga ◽  
Yukako Yamane ◽  
Etsuro Ito ◽  
Kazuhiro Abe ◽  
Kazushige Kawabata ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Atomic Force Microscopy ◽  
Membrane Surface ◽  
Force Microscopy ◽  
Atomic Force

scholarly journals Corrosion Behavior and Mechanical Properties of a Nanocomposite Superhydrophobic Coating

Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 652
Author(s):  
Divine Sebastian ◽  
Chun-Wei Yao ◽  
Lutfun Nipa ◽  
Ian Lian ◽  
Gary Twu
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Atomic Force Microscopy ◽  
Nanocomposite Coating ◽  
Superhydrophobic Coating ◽  
Force Microscopy ◽  
Atomic Force ◽  
Microscopy Images ◽  
Scanning Electron

In this work, a mechanically durable anticorrosion superhydrophobic coating is developed using a nanocomposite coating solution composed of silica nanoparticles and epoxy resin. The nanocomposite coating developed was tested for its superhydrophobic behavior using goniometry; surface morphology using scanning electron microscopy and atomic force microscopy; elemental composition using energy dispersive X-ray spectroscopy; corrosion resistance using atomic force microscopy; and potentiodynamic polarization measurements. The nanocomposite coating possesses hierarchical micro/nanostructures, according to the scanning electron microscopy images, and the presence of such structures was further confirmed by the atomic force microscopy images. The developed nanocomposite coating was found to be highly superhydrophobic as well as corrosion resistant, according to the results from static contact angle measurement and potentiodynamic polarization measurement, respectively. The abrasion resistance and mechanical durability of the nanocomposite coating were studied by abrasion tests, and the mechanical properties such as reduced modulus and Berkovich hardness were evaluated with the aid of nanoindentation tests.

scholarly journals The Infuence of Salicin on Rheological and Film-Forming Properties of Collagen

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1661
Author(s):  
Katarzyna Adamiak ◽  
Katarzyna Lewandowska ◽  
Alina Sionkowska
Keyword(s):  
Mechanical Properties ◽  
Atomic Force Microscopy ◽  
Infrared Spectroscopy ◽  
Rheological Properties ◽  
Silver Carp ◽  
Shear Tests ◽  
Force Microscopy ◽  
Atomic Force ◽  
Film Forming ◽  
Potential Applications

Collagen films are widely used as adhesives in medicine and cosmetology. However, its properties require modification. In this work, the influence of salicin on the properties of collagen solution and films was studied. Collagen was extracted from silver carp skin. The rheological properties of collagen solutions with and without salicin were characterized by steady shear tests. Thin collagen films were prepared by solvent evaporation. The structure of films was researched using infrared spectroscopy. The surface properties of films were investigated using Atomic Force Microscopy (AFM). Mechanical properties were measured as well. It was found that the addition of salicin modified the roughness of collagen films and their mechanical and rheological properties. The above-mentioned parameters are very important in potential applications of collagen films containing salicin.

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 Anisotropic Mechanical Properties of Living Cells Revealed by Integrated Spinning Disk Confocal and Atomic Force Microscopy

2018 ◽  
Vol 114 (3) ◽  
pp. 513a
Author(s):  
Yuri M. Efremov ◽  
Mirian Velay-Lizancos ◽  
Daniel M. Suter ◽  
Pablo D. Zavattieri ◽  
Arvind Raman
Keyword(s):  
Mechanical Properties ◽  
Atomic Force Microscopy ◽  
Living Cells ◽  
Force Microscopy ◽  
Atomic Force ◽  
Spinning Disk ◽  
Anisotropic Mechanical Properties

In situ X-ray Scattering Study of the Formation of Au Nano Crystals During Thermal Annealing

2007 ◽  
Vol 1027 ◽  
Author(s):  
Do Young Noh ◽  
Ki-Hyun Ryu ◽  
Hyon Chol Kang
Keyword(s):  
Thermal Annealing ◽  
Bragg Reflection ◽  
Ex Situ ◽  
X Ray ◽  
Force Microscopy ◽  
X Ray Scattering ◽  
Atomic Force ◽  
Au Thin Films ◽  
Ray Scattering

AbstractThe transformation of Au thin films grown on sapphire (0001) substrates into nano crystals during thermal annealing was investigated by in situ synchrotron x-ray scattering and ex situ atomic force microscopy (AFM). By monitoring the Au(111) Bragg reflection and the low Q reflectivity and comparing them with ex situ AFM images, we found that polygonal-shape holes were nucleated and grow initially. As the holes grow larger and contact each other, their boundary turns into Au nano crystals. The Au nano crystals have a well-defined (111) flat top surface and facets in the in-plane direction.

Sign in / Sign up

Export Citation Format

Share Document