Synthesis of graphene oxide-epoxy resin encapsulated urea-formaldehyde microcapsule by in situ polymerization process

2016 ◽  
Vol 39 (3) ◽  
pp. 636-644 ◽  
Author(s):  
Sourav Sarkar ◽  
Byungki Kim
Keyword(s):  
Graphene Oxide ◽  
Epoxy Resin ◽  
In Situ Polymerization ◽  
Urea Formaldehyde ◽  
Polymerization Process

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 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.

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.

Preparation and Characterization of Hexadecane Microcapsule Phase Change Materials by In Situ Polymerization

2013 ◽  
Vol 815 ◽  
pp. 367-370 ◽  
Author(s):  
Xiao Qiu Song ◽  
Yue Xia Li ◽  
Jing Wen Wang
Keyword(s):  
Particle Size ◽  
Phase Change ◽  
Phase Change Materials ◽  
In Situ Polymerization ◽  
Urea Formaldehyde ◽  
Agitation Speed ◽  
Urea Formaldehyde Resin ◽  
Formaldehyde Resin ◽  
Mass Ratio

Hexadecane microcapsule phase change materials were prepared by the in-situ polymerization method using hexadecane as core materials, urea-formaldehyde resin and urea-formaldehyde resin modified with melamine as shell materials respectively. Effect of melamine on the properties of microcapsules was studied by FTIR, biomicroscopy (UBM), TGA and HPLC. The influences of system concentration, agitation speed and mass ratio of wall to core were also investigated. The results indicated that hexadecane was successfully coated by the two types of shell materials. The addition of melamine into the urea-formaldehyde resin microcapsule reduced microcapsule particle size and microencapsulation efficiency. The influences of factors such as system concentration, agitation speed and mass ratio of wall to core to different wall materials microcapsules presented different variety trends of the microcapsule particle size.

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