scholarly journals Influence of Graphene Oxide Contents on Mechanical Behavior of Polyurethane Composites Fabricated with Different Diisocyanates

Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 444
Author(s):  
Nadia Akram ◽  
Muhammad Saeed ◽  
Muhammad Usman ◽  
Asim Mansha ◽  
Fozia Anjum ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Mechanical Behavior ◽  
In Situ Polymerization ◽  
Complex Modulus ◽  
Phase Segregation ◽  
Hexamethylene Diisocyanate ◽  
Polymerization Process ◽  
Gravimetric Analysis ◽  
Polyurethane Composites

The exceptional behavior of graphene has not yet been entirely implicit in the polymer matrix. To explore this fact in the present work, two series of Polyurethan (PU) composites were synthesized. The structural modification was observed by the use of two different diisocyanate of methylene diisocyanate (MDI) and hexamethylene diisocyanate (HMDI) in hydroxylterminated polybutadiene (HTPB) by using I,4 Butane diol (BD) as the chain extender. The variation in hard segment up to 25 (wt.%) in both series led to significant changes in the mechanical behavior of graphene oxide (GO) induced composites. Both series were prepared by an in situ polymerization process. Fourier transform infrared (FTIR) analysis showed a peak in the region of 1700 cm−1, which confirmed the conversion of the NCO group into urethane linkages. Thermal gravimetric analysis (TGA) revealed a thermal stability up to 450 °C @ 90% weight loss. The swelling behavior showed the optimum uptake of 30% of water and 40% of dimethyl sulfoxide (DMSO) with aliphatic diisocyanate. The values of storage modulus (E′), complex modulus (E*), and compliance complex (D*) were observed up to 7 MPa, 8 Mpa, and 0.7 MPa−1, respectively. The degree of entanglement (N) values were calculated from DMA and were found in the range of 1.7 × 10−4 (mol/m3). Phase segregation of PU was observed by scanning electron microscopy (SEM), elucidating the morphology of composites.

In Situ Fabrication of Nanoscale Graphene Oxide/Polyaniline Composite and its Electrochemical Properties

2010 ◽  
Vol 148-149 ◽  
pp. 1547-1550 ◽  
Author(s):  
Hua Lan Wang ◽  
Qing Li Hao ◽  
Xi Feng Xia ◽  
Zhi Jia Wang ◽  
Jiao Tian ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Graphene Oxide ◽  
Photoelectron Spectroscopy ◽  
In Situ Polymerization ◽  
Ammonium Persulfate ◽  
Polymerization Process ◽  
Electrochemical Test ◽  
X Ray ◽  
Transmission Electron

A graphene oxide/polyaniline composite was synthesized by an in situ polymerization process. This product was simply prepared in an ethylene glycol medium, using ammonium persulfate as oxidant in ice bath. The composite was characterized by field emission scanning electron microscopy, transmission electron microscopy, X-Ray photoelectron spectroscopy, Raman spectroscopy and electrochemical test. The composite material showed a good electrochemical performance.

scholarly journals In situ polymerization of polypyrrole on cotton fabrics as flexible electrothermal materials

2019 ◽  
Vol 14 ◽  
pp. 155892501982744 ◽  
Author(s):  
Juan Xie ◽  
Wei Pan ◽  
Zheng Guo ◽  
Shan Shan Jiao ◽  
Ling Ping Yang
Keyword(s):  
Thermal Stability ◽  
Tensile Strength ◽  
In Situ Polymerization ◽  
Thermo Gravimetric Analysis ◽  
Cotton Fabrics ◽  
Morphological Properties ◽  
Polymerization Process ◽  
Maximum Temperature ◽  
Gravimetric Analysis

Polypyrrole/cotton composites have substantial application potential in flexible heating devices due to their flexibility, high conductivity, and thermal stability. In this context, a series of flexible polypyrrole/cotton fabrics were intrinsically prepared using in situ polymerization process with the different Py/FeCl3 concentration ratios. To investigate their structural and morphological properties, thermal stability, tensile strength, conductivity, and heat-generating property, the composite fabrics were subjected to Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray diffraction, thermo-gravimetric analysis, mechanical properties, and resistivity measurements. The results showed that polypyrrole/cotton fabrics exhibited a low resistivity of 0.37 Ω cm. Temperature–time curve showed that temperature of the polypyrrole/cotton fabrics increased very quickly from room temperature to a steady-state maximum temperature of 168.3°C within 3 min at applied voltage of 5 V. Tensile strength of polypyrrole/cotton composites reached to 58 MPa, which far surpassed raw cotton fabrics. Therefore, polypyrrole/cotton fabrics have exhibited high electrical, thermal properties, and mechanical strength, which can be utilized as an ideal flexible heating element.

In situ polymerization of mechanically reinforced, thermally healable graphene oxide/polyurethane composites based on Diels–Alder chemistry

2014 ◽  
Vol 2 (48) ◽  
pp. 20642-20649 ◽  
Author(s):  
Jinhui Li ◽  
Guoping Zhang ◽  
Libo Deng ◽  
Songfang Zhao ◽  
Yongju Gao ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
In Situ Polymerization ◽  
Diels Alder ◽  
Mechanical Reinforcement ◽  
Covalently Bonded ◽  
Polyurethane Composites

Covalently bonded graphene oxide/polyurethane composites with significant mechanical reinforcement and thermally healable capability were developed via in situ polymerization based on Diels–Alder chemistry.

scholarly journals The Effect of Hexamethylene Diisocyanate-Modified Graphene Oxide as a Nanofiller Material on the Properties of Conductive Polyaniline

Polymers ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1032 ◽  
Author(s):  
José Antonio Luceño Sánchez ◽  
Ana Maria Díez-Pascual ◽  
Rafael Peña Capilla ◽  
Pilar García Díaz
Keyword(s):  
Graphene Oxide ◽  
Flexible Electronics ◽  
Organic Solar Cells ◽  
High Performance ◽  
In Situ Polymerization ◽  
Low Cost ◽  
Hexamethylene Diisocyanate ◽  
Charge Transfer Complexes ◽  
Modified Graphene Oxide

Conducting polymers like polyaniline (PANI) have gained a lot of interest due to their outstanding electrical and optoelectronic properties combined with their low cost and easy synthesis. To further exploit the performance of PANI, carbon-based nanomaterials like graphene, graphene oxide (GO) and their derivatives can be incorporated in a PANI matrix. In this study, hexamethylene diisocyanate-modified GO (HDI-GO) nanosheets with two different functionalization degrees have been used as nanofillers to develop high-performance PANI/HDI-GO nanocomposites via in situ polymerization of aniline in the presence of HDI-GO followed by ultrasonication and solution casting. The influence of the HDI-GO concentration and functionalization degree on the nanocomposite properties has been examined by scanning electron microscopy (SEM), Raman spectroscopy, X-ray diffraction (XRD), thermogravimetric analysis (TGA), tensile tests, zeta potential and four-point probe measurements. SEM analysis demonstrated a homogenous dispersion of the HDI-GO nanosheets that were coated by the matrix particles during the in situ polymerization. Raman spectra revealed the existence of very strong PANI-HDI-GO interactions via π-π stacking, H-bonding, and hydrophobic and electrostatic charge-transfer complexes. A steady enhancement in thermal stability and electrical conductivity was found with increasing nanofiller concentration, the improvements being higher with increasing HDI-GO functionalization level. The nanocomposites showed a very good combination of rigidity, strength, ductility and toughness, and the best equilibrium of properties was attained at 5 wt % HDI-GO. The method developed herein opens up a versatile route to prepare multifunctional graphene-based nanocomposites with conductive polymers for a broad range of applications including flexible electronics and organic solar cells.

scholarly journals In Situ Polymerization of Nylon 66/Reduced Graphene Oxide Nanocomposites

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Xiaochao Duan ◽  
Bin Yu ◽  
Tonghui Yang ◽  
Yanpeng Wu ◽  
Hao Yu ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
In Situ Polymerization ◽  
Early Stage ◽  
Ammonium Hydroxide ◽  
Polymerization Process ◽  
Nylon 66 ◽  
Reduced Graphene

A one-step method of in situ polymerization of nylon 66/reduced graphene oxide (PA66/rGO) nanocomposites is first proposed, simply by introducing graphene oxide (GO) into PA66 salt with the existence of ammonium hydroxide. The GO is prereduced by the ammonium hydroxide at an early stage of the polymerization process and then grafted on the PA66 chains, accompanied with the thermal reduction of GO. The PA66 chains were grafted onto the GO nanosheets through the condensation between the oxygen-containing functional groups of the GO and the terminal amino ends of the PA66 chains. The effect of GO on the mechanical properties, especially tensile strength, of nanocomposites was investigated. The results revealed that the incorporation of a very small amount (about 1 wt%) of GO caused a significant improvement in ultimate tensile strength (about 17%). The SEM of the fracture surface of composites indicated a good dispersion of rGO in the matrix. Raman spectroscopy, thermogravimetric analysis (TGA), scanning electron microscope (SEM), Fourier transformed infrared spectroscopy (FTIR), and XRD patterns of rGO, which was isolated from nanocomposites, revealed that the GO nanolayers were simultaneously reduced and PA66 chains were grafted on the rGO nanosheet during the polymerization process. The rGO grafted with the PA66 chain increases its compatibility in the PA66 matrix and effectively enhanced the interfacial energy of the composites.

Sign in / Sign up

Export Citation Format

Share Document