Studies on the Properties of Epoxy Resins Modified with Novel Liquid Crystalline Polyurethane

2010 ◽  
Vol 150-151 ◽  
pp. 727-731 ◽  
Author(s):  
Zhi Yi Huang ◽  
Shao Rong Lu ◽  
Zhi You Yang ◽  
Chun He Yu ◽  
Dong Guo
Keyword(s):  
Thermal Decomposition ◽  
Tensile Strength ◽  
Epoxy Resin ◽  
Epoxy Resins ◽  
Liquid Crystalline ◽  
Bending Strength ◽  
Decomposition Temperature ◽  
Thermal Decomposition Temperature ◽  
The Impact ◽  
Unmodified Epoxy

Liquid crystal polyurethane (LCPBI) containing biphenylnate and imide units was synthesized and characterized and used to modify the conventional epoxy resin (E-51). Experimental results revealed that the impact strength of the epoxy resin modified with LCPBI was 2.5 times higher than that of unmodified epoxy resin, and the tensile strength as well as the bending strength was also improved. The thermal decomposition temperature of modified systems was also 15-20oC higher than that of the unmodified system, and the fracture structures of the blends was investigated by SEM.

scholarly journals An Effective Method for Preparation of Liquid Phosphoric Anhydride and Its Application in Flame Retardant Epoxy Resin

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2205
Author(s):  
Qian Li ◽  
Yujie Li ◽  
Yifan Chen ◽  
Qiang Wu ◽  
Siqun Wang
Keyword(s):  
Flame Retardant ◽  
Epoxy Resin ◽  
Epoxy Resins ◽  
Oxygen Index ◽  
Decomposition Temperature ◽  
Ease Of Use ◽  
Limiting Oxygen Index ◽  
Good Thermal Stability ◽  
Low Viscosity ◽  
The Impact

A novel liquid phosphorous-containing flame retardant anhydride (LPFA) with low viscosity was synthesized from 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) and methyl tetrahydrophthalic anhydride (MeTHPA) and further cured with bisphenol-A epoxy resin E-51 for the preparation of the flame retardant epoxy resins. Both Fourier transform infrared spectroscopy (FT-IR), mass spectrometry (MS) and nuclear magnetic resonance (NMR) measurements revealed the successful incorporation of DOPO on the molecular chains of MeTHPA through chemical reaction. The oxygen index analysis showed that the LPFA-cured epoxy resin exhibited excellent flame retardant performance, and the corresponding limiting oxygen index (LOI) value could reach 31.2%. The UL-94V-0 rating was achieved for the flame retardant epoxy resin with the phosphorus content of 2.7%. With the addition of LPFA, the impact strength of the cured epoxy resins remained almost unchanged, but the flexural strength gradually increased. Meanwhile, all the epoxy resins showed good thermal stability. The glass transition temperature (Tg) and thermal decomposition temperature (Td) of epoxy resin cured by LPFA decreased slightly compared with that of MeTHPA-cured epoxy resin. Based on such excellent flame retardancy, low viscosity at room temperature and ease of use, LPFA showed potential as an appropriate curing agent in the field of electrical insulation materials.

Effect of Nano Cr2O3 in HTPB/AP/Al Based Composite Propellant Formulations

2016 ◽  
Vol 66 (2) ◽  
pp. 100 ◽  
Author(s):  
Dhirendra Kshirsagar ◽  
Ramesh Kurva ◽  
Kashinath Dhabbe ◽  
Lalita Jawale ◽  
Sudhir Singh ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Tensile Strength ◽  
Thermal Properties ◽  
Elastic Modulus ◽  
Chromium Oxide ◽  
Decomposition Temperature ◽  
Solid Loading ◽  
Thermal Decomposition Temperature ◽  
Composite Propellant ◽  
Ballistic Properties

<p>Different compositions have been prepared by incorporating nano sized chromium oxide from 0.25 % to 1 % in HTPB/AP/Al based composite propellant formulation having 86% of solid loading and studied its effect on viscosity build-up, thermal, mechanical and ballistic properties. The findings reveal that on increasing the percentage of nano Cr2O3 in the composition, there is an increase in end of mix viscosity, elastic modulus and tensile strength while elongation decreases accordingly. The data on thermal properties envisage the reduction in thermal decomposition temperature of ammonium perchlorate as well as formulations based on HTPB/AP/Al. The data on ballistic properties reveal that there is an enhancement in burning rate from 6.11 mm/s to 7.88 mm/s at 6.86 MPa, however, marginal increase in  pressure exponent (‘n’ values) from 0.35 to 0.53 with 1 wt % of nano Cr2O3 was observed  in comparison to reference composition without chromium oxide. </p><p> </p>

Thermomechanical Properties and Morphology of Liquid Crystalline Polyurethane/Epoxy Resin Composites

2011 ◽  
Vol 194-196 ◽  
pp. 1421-1425 ◽  
Author(s):  
Jian Feng Ban ◽  
Shao Rong Lu ◽  
Dong Guo ◽  
Kuo Liu ◽  
Chong Xi Luo
Keyword(s):  
Epoxy Resin ◽  
Liquid Crystalline ◽  
Decomposition Temperature ◽  
Thermomechanical Properties ◽  
Resin Composites ◽  
Flexible Chain ◽  
Polyurethane Elastomers ◽  
Fracture Feature ◽  
Epoxy Resin Composites ◽  
The Impact

One new kind of epoxy resin toughening agent defined as liquid crystalline polyurethane elastomers (LCPUE) containing mesogenic ester groups and trithylene glycol flexible chain was synthesized and its nematic structure was observed by POM and XRD. The LCPUE was to modify the epoxy resin (E-51). The mechanical properties, fracture surface morphology, and thermal properties of the E-51/LCPUE curing system were systematically investigated. Experimental results revealed that the impact strength of the epoxy resin modified with LCPU is 1.9 times higher than that of the unmodified system, enhanced the thermal decomposition temperature by about 12 °C, and the fracture surfaces all modified systems display tough fracture feature.

scholarly journals Preparation and Characterization of Liquid Crystalline Polyurethane/Al2O3/Epoxy Resin Composites for Electronic Packaging

2012 ◽  
Vol 2012 ◽  
pp. 1-4 ◽  
Author(s):  
Shaorong Lu ◽  
Jianfeng Ban ◽  
Kuo Liu
Keyword(s):  
Mechanical Properties ◽  
Epoxy Resin ◽  
Liquid Crystalline ◽  
Coefficient Of Thermal Expansion ◽  
Decomposition Temperature ◽  
Resin Composites ◽  
Thermal Decomposition Temperature ◽  
Epoxy Resin Composites ◽  
Oxidation Analysis

Liquid crystalline polyurethane (LCPU)/Al2O3/epoxy resin composites were prepared by using LCPU as modifier. The mechanical properties, thermal stability, and electrical properties of the LCPU/Al2O3/epoxy resin composites were investigated systematically. The thermal oxidation analysis indicated that LCPU/Al2O3/epoxy resin composites can sustain higher thermal decomposition temperature. Meanwhile, coefficient of thermal expansion (CTE) was also found to decrease with addition of LCPU and nano-Al2O3.

Mechanical properties of cured epoxy resin

2021 ◽  
Author(s):  
Sergey Savotchenko ◽  
Ekaterina Kovaleva
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Impact Strength ◽  
Epoxy Resin ◽  
Mass Fraction ◽  
Mechanical Characteristics ◽  
Bending Strength ◽  
The Impact ◽  
Impact Viscosity

We study experimentally the influence of mass fraction of L-20 hardener cold cure on mechanical properties of epoxy diane resin ED-20. We measure the hardness, tensile strength, bending strength and impact strength of resin at different values of the hardener mass fraction. It is found that the ratio hardener mass fraction of 1:0.9 leads to the highest values of the hardness, tensile strength, compressive strength and bending strength. The impact viscosity is maximum at the ratio hardener mass fraction of 1:0.8. The optimal ratio of a non-toxic safe hardener to the resin is derived based on obtained mechanical characteristics.

Improved Wear Resistance of UHMWPE Fibers by Modified Nano-Graphite

2019 ◽  
Vol 960 ◽  
pp. 148-154
Author(s):  
Hong Qiu Wang ◽  
Jia You Quan ◽  
Jun Rong Yu ◽  
Yan Wang ◽  
Jing Zhu ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Thermal Decomposition ◽  
Tensile Strength ◽  
Wear Resistance ◽  
Thermogravimetric Analysis ◽  
Decomposition Temperature ◽  
Thermal Decomposition Temperature ◽  
Uhmwpe Fiber ◽  
Uhmwpe Fibers ◽  
Ultra High Molecular Weight

Single ultra-high molecular weight polyethylene (UHMWPE) fiber was modified by modified nano-graphite (NG) in wear resistance. Wear resistance, tensile strength, thermogravimetric analysis (TGA) were used to characterize the effect of modified NG on the properties of UHMWPE fiber. The results showed that with the increasing content of modified NG, the wear resistance of UHMWPE fiber was enhanced and its tensile strength was decreased. Considering the tensile strength and wear resistance of fiber, the optimum content of modified NG in UHMWPE fiber was around 0.58%. At this content, the wear resistance and thermal decomposition temperature of UHMWPE fiber were increased 1.88 times and 50°C respectively than pure UHMWPE fiber.

scholarly journals Development of Epoxy Resin-Based Elastomeric Microfluidic Devices Using CO2 Laser Ablation for DNA-Amplification Point-Of-Care (POC) Applications: Assessment of Microchannels' Dimensions and Quality

2021 ◽  
Author(s):  
Heba Mansour ◽  
Ahmed M.R. Fath El-Bab ◽  
Emad A. Soliman ◽  
Ahmed L. Abdel-Mawgood
Keyword(s):  
Laser Ablation ◽  
Epoxy Resin ◽  
Epoxy Resins ◽  
Carbon Dioxide Laser ◽  
Microfluidic Devices ◽  
Microfluidic Chips ◽  
Laser Technique ◽  
Lab On Chip ◽  
Expensive Equipment ◽  
The Impact

Abstract Microfluidic devices are a rising technology to automatize chemical and biological operations. In this context, laser ablation has significant potential for polymer-based microfluidic platforms' fast and economical manufacturing. Nevertheless, the manufacturing of epoxy-based microfluidic chips is considered highly cost full due to demand for cleanroom facilities that utilize expensive equipment and lengthy processes. Therefore, this study targeted investigating the feasibility of epoxy resins to be fabricated as a lab-on-chip using carbon dioxide laser ablation. The chemical structural properties and thermal stability of the plain epoxy resins were characterized by Fourier transform infrared spectral analysis (FT-IR) and thermogravimetric analysis (TGA). Moreover, a specific migration test was performed to quantify potential migrants by gas chromatography coupled to mass spectrometry (GC-MS) to prove that the cured epoxy resin would not release unreacted monomers to the biological solution test, which caused inhibition of the sensitive biological reactions. By investigating the impact of this process on microchannels' dimensions and quality, a laser technique using CO2 laser was used in vector mode to engrave into a transparent epoxy resin chip. The resulting microchannels were characterized using 3D Laser microscopy. The outcomes of this study showed considerable potential for laser ablation in machining the epoxy-based chips, whereas the microchannels were produced with minor bulges' height (0.027 µm) with no clogging. Moreover, a reasonable depth of 99.31 µm with roughness (Ra) of 14.52 µm was obtained at a laser speed of 5 mm/s and laser power of 1.8 W. This process can produce epoxy resin-based microfluidic chips without the need for cleanroom facilities that require expensive equipment and lengthy process.

Research Progress of New Methods for Toughening Epoxy Resin

2012 ◽  
Vol 490-495 ◽  
pp. 3598-3602 ◽  
Author(s):  
Li Ying Guo ◽  
Li Yan Wang ◽  
Xin Su
Keyword(s):  
Epoxy Resin ◽  
Epoxy Resins ◽  
Liquid Crystalline ◽  
Research Progress ◽  
Nano Particle ◽  
Technology Research ◽  
Future Prospects ◽  
Thermoplastic Resin ◽  
Rigid Polymer ◽  
New Methods

The epoxy is a thermosetting resin, for the lack of toughness after cured ,a brief introduction of epoxy resin toughening technology research progress, detailed in the recent years a number of toughening epoxy resins new methods, including toughened thermoplastic resin, IPN toughening, core-shell particle toughening, thermotropic liquid crystalline toughness, rigid polymer toughening, nano-particle toughening and so on. At last, the paper provided an overview of the progress of epoxy toughening modification technology and its future prospects.

Sign in / Sign up

Export Citation Format

Share Document