scholarly journals Blends of Cyanate Ester and Phthalonitrile–Polyhedral Oligomeric Silsesquioxane Copolymers: Cure Behavior and Properties

Polymers ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 54 ◽  
Author(s):  
Xiaodan Li ◽  
Fei Zhou ◽  
Ting Zheng ◽  
Ziqiao Wang ◽  
Heng Zhou ◽  
...  
Keyword(s):  
Chemical Reactivity ◽  
Polyhedral Oligomeric Silsesquioxane ◽  
Far Infrared ◽  
Mechanical Analysis ◽  
Cyanate Ester ◽  
Scanning Calorimetry ◽  
Good Thermal Stability ◽  
Cure Behavior ◽  
Low Viscosity ◽  
Oligomeric Silsesquioxane

Blends of cyanate ester and phthalonitrile–polyhedral oligomeric silsesquioxane copolymers were prepared, and their cure behavior and properties were compared via differential scanning calorimetry (DSC) analysis, thermogravimetric (TG) analysis, dynamic mechanical analysis, Fourier-transform far-infrared (FTIR) spectroscopy, and rheometric studies. The copolymer blends showed high chemical reactivity, low viscosity, and good thermal stability (TG temperatures were above 400 °C). The glass-transition temperature of the blends increased by at least 140 °C compared to cyanate ester resin. The blends are suitable for preparing carbon-fiber-reinforced composite materials via a winding process and a prepreg lay-up process with a molding technique. The FTIR data showed that the polymerization products contained triazine-ring structures that were responsible for the superior thermal properties.

Gelation Behavior, Morphology, Thermal and Viscoelastic Properties of Epoxy-Cyanate Ester/Polyhedral Oligomeric Silsesquioxane (POSS) Nanocomposites

2006 ◽  
Vol 11-12 ◽  
pp. 323-326 ◽  
Author(s):  
Jun Peng Ma ◽  
Qi Fang Li
Keyword(s):  
Polyhedral Oligomeric Silsesquioxane ◽  
Mechanical Analysis ◽  
Decomposition Temperature ◽  
Cyanate Ester ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Weight Percentage ◽  
Organic Hybrid ◽  
Gelation Behavior ◽  
Oligomeric Silsesquioxane

Epoxy-cyanate (EP-CE) ester composites containing the inorganic-organic hybrid polyhedral oligomeric silsesquioxane (POSS) octaisobutyl(T8)-POSS (oib-POSS) were prepared. These EP-CE/POSS composites were characterized by gelation characteristics, transmission election microscopy (TEM), X-ray diffraction (XRD), differential scanning calorimetry (DSC), thermal gravimetric analyses (TGA) and dynamic mechanical analysis (DMTA). The glass transition temperature (Tg) and thermal decomposition temperature (Tdec) of composites increased compared with the neat epoxy-cyanate ester with the increment of POSS content. Additionally, all the EP-CE/POSS composites exhibited higher storage modulus (E’) values (temperature>Tg) than the pure resins. The loss factor peak intensities decreased as the weight percentage of POSS increases. TEM and XRD showed that phase-separated aggregates of POSS were found in matrix, because POSS did not react with the resin.

scholarly journals Polytriazole resins toughened by an azide-terminated polyhedral oligomeric silsesquioxane (OADTP)

e-Polymers ◽  
2021 ◽  
Vol 21 (1) ◽  
pp. 289-298
Author(s):  
Zhuoer Yu ◽  
Jun Zhang ◽  
Bangqiang Wu ◽  
Liqiang Wan ◽  
Farong Huang
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Performance Test ◽  
Polyhedral Oligomeric Silsesquioxane ◽  
Mechanical Analysis ◽  
Good Thermal Stability ◽  
Impact Performance ◽  
Oligomeric Silsesquioxane ◽  
The Impact ◽  
Electronic Microscope

Abstract An azido-terminated polyhedral oligomeric silsesquioxane (POSS) compound, octakis(azidopropyl-3-oxycarbonyl-1-decyl-10-thiopropyl-3-)POSS (OADTP), is synthesized and characterized. POSS-polytriazole (PTA) resins are prepared from an azide, an alkyne monomer, and OADTP. The toughening effect of OADTP on PTA resins is analyzed by impact performance test and electronic microscope characterization, and the thermal performance of resins is measured by thermogravimetric analysis and dynamic mechanical analysis. The results show that the addition of the POSS can improve the mechanical properties of PTA resins. The impact strength of POSS-PTA resins first increases and then decreases with the increase in the POSS compound, and the maximum one arrives at 54.8 kJ m−2 which increases by 44.2% as compared to 38 kJ m−2 of the PTA resin. A good thermal stability remains in POSS-PTA resins.

scholarly journals The Effect of POSS Type on the Shape Memory Properties of Epoxy-Based Nanocomposites

Molecules ◽  
2020 ◽  
Vol 25 (18) ◽  
pp. 4203
Author(s):  
Avraham I. Bram ◽  
Irina Gouzman ◽  
Asaf Bolker ◽  
Noam Eliaz ◽  
Ronen Verker
Keyword(s):  
Transition Temperature ◽  
Shape Memory ◽  
Crosslinking Density ◽  
Mechanical Analysis ◽  
Thermomechanical Properties ◽  
Space Environment ◽  
Scanning Calorimetry ◽  
Space Applications ◽  
Curing Conditions ◽  
Oligomeric Silsesquioxane

Thermally activated shape memory polymers (SMPs) can memorize a temporary shape at low temperature and return to their permanent shape at higher temperature. These materials can be used for light and compact space deployment mechanisms. The control of transition temperature and thermomechanical properties of epoxy-based SMPs can be done using functionalized polyhedral oligomeric silsesquioxane (POSS) additives, which are also known to improve the durability to atomic oxygen in the space environment. In this study, the influence of varying amounts of two types of POSS added to epoxy-based SMPs on the shape memory effect (SME) were studied. The first type contained amine groups, whereas the second type contained epoxide groups. The curing conditions were defined using differential scanning calorimetry and glass transition temperature (Tg) measurements. Thermomechanical and SME properties were characterized using dynamic mechanical analysis. It was found that SMPs containing amine-based POSS show higher Tg, better shape fixity and faster recovery speed, while SMPs containing epoxide-based POSS have higher crosslinking density and show superior thermomechanical properties above Tg. This work demonstrates how the Tg and SME of SMPs can be controlled by the type and amount of POSS in an epoxy-based SMP nanocomposite for future space applications.

Carbon-fibre-reinforced modified cyanate ester winding composites and their thermomechanical properties

2018 ◽  
Vol 31 (2) ◽  
pp. 154-167 ◽  
Author(s):  
Yu Qing Cui ◽  
Zhong Wei Yin
Keyword(s):  
Mechanical Properties ◽  
Carbon Fibre ◽  
Resin Composite ◽  
Thermomechanical Property ◽  
Thermomechanical Properties ◽  
Cyanate Ester ◽  
Resin Matrix ◽  
Scanning Calorimetry ◽  
Good Thermal Stability ◽  
Sizing Agents

Although the extensive research has expanded on the modification of cyanate ester (CE) resins and the mechanical properties of CE composites, very few studies have been conducted on carbon fibre (CF)/modified CE winding composites and the thermomechanical properties of the composites. In this research, epoxy (EP)-modified novolac cyanate ester (NCE) and bismaleimide (BMI)-modified NCE resins were prepared. The CF/modified CE winding composites were manufactured, and their thermomechanical properties were tested. The optimal winding process was determined, and a preheating technique was implemented. Then, the EP/CE resin (10:90) and the BMI–DBA/CE resin (10:90) were selected as the resin matrix of the winding composite based on the viscosity properties, mechanical properties and thermal analysis (using thermogravimetric analysis and differential scanning calorimetry) of the modified CE resin. The selected resin exhibited good manufacturability at 70°C, good thermal stability and high Tg (above 370°C). The thermomechanical property tests indicate that the modified CE resin composite exhibits an outstanding mechanical strength at room temperature and at high temperatures (130°C, 150°C and 180°C) compared with that of the pure CE resin composite. The reasons for this enhancement can be attributed to a toughening mechanism and the effect of sizing agents on the CFs.

Bio-Crude by Acidic Phenolation and Carbamation for the Preparation of Phenolic Thermosetting Resin and Its Application in Thermoresistant Laminates

2019 ◽  
Vol 17 (4) ◽  
Author(s):  
Huan Wang ◽  
Zhuo Wang ◽  
Penggang Ren ◽  
Mingcun Wang
Keyword(s):  
High Performance ◽  
Phenolic Resin ◽  
Mechanical Test ◽  
Chemical Reactivity ◽  
Cost Effective ◽  
Mechanical Analysis ◽  
Thermosetting Resin ◽  
Scanning Calorimetry ◽  
Three Point Bending ◽  
Mechanical Performances

Abstract Fir sawdust was liquefied in phenol solvent under acidic catalyst at 135, 150 and 165 °C, respectively; after neutralization, bio-crude was obtained where contained oil-like liquid and tiny powder-like residue. The bio-crude was chemically modified with urea at high temperature (e. g. > 130 °C) to form carbamate so as to improve chemical reactivity of bio-crude in phenolic resin synthesis. The carbamate-containing bio-crude was condensed with paraformaldehyde into thermosetting phenolic resin. Finally, this biomass-derived phenolic resin matrixed silica fabric laminates were processed. The uncured and thermally cured bio-based resins were characterized by the techniques of Differential Scanning Calorimetry (DSC), Fourier Transform Infrared spectrum (FT-IR), rheology and Thermogravimetric Analysis (TGA), and the laminates’ structure and mechanical performances were studied using the methods of Scanning Electron Microscopy (SEM), three point bending mechanical test and Dynamic Mechanical Analysis (DMA). The results showed: (1) the chemical reactivity of bio-crude was highly improved by carbamation; (2) biomass-derived thermosetting phenolic resin was thermally curable at 150–250 °C (with two exothermic peaks at 185 °C and 220 °C); (3) the char yield was about 47 %, which was not in apparent relationship with sawdust liquefaction temperatures; (4) flexural strength of silica fabric laminates at room temperature was around 357 MPa (similar with that of conventional phenolic laminate); (5) glass transition temperature of silica fabric laminate was above 270 °C (much higher than Tg of conventional phenolic resin laminate, which is normally at 215 °C). The biomass-derived phenolic resin is expected to be widely used as cost-effective and environment-friendly thermosetting resin in the application of high-performance composites.

Determination of the Curing Techniques of Octaepoxysilsesquioxane with a Diamine

2012 ◽  
Vol 549 ◽  
pp. 157-160
Author(s):  
Zeng Ping Zhang ◽  
Jian Zhong Pei ◽  
Chang Qing Fang ◽  
Shuan Fa Chen
Keyword(s):  
Differential Scanning Calorimetry ◽  
Polyhedral Oligomeric Silsesquioxane ◽  
Resin System ◽  
Scanning Calorimetry ◽  
Curing Agents ◽  
Oligomeric Silsesquioxane ◽  
Epoxy Groups

Octaepoxysilsesquioxane (POSS-Ep), a kind of functional polyhedral oligomeric silsesquioxane (POSS) was cured with 4,4'-diaminodiphenylsulfone diamine (DDS) in this study. Possessing epoxy groups, it can be cured thermally with certain curing agents including amines. Differential scanning calorimetry (DSC) was used to determine the curing techniques of the POSS-Ep/DDS resin system in this study. The appropriate curing technique for this resin is set as: 130°C/2h+ 160°C/2h+200°C/2h.

Synthesis of a lignin polymer model consisting of only phenolic β-O-4 linkages and testing its reactivity under alkaline conditions 10th EWLP, Stockholm, Sweden, August 25–28, 2008

Holzforschung ◽  
2009 ◽  
Vol 63 (6) ◽  
Author(s):  
Jackson D. Megiatto ◽  
Emmanuel Cazeils ◽  
Stéphane Grelier ◽  
Christian Gardrat ◽  
Frédérique Ham-Pichavant ◽  
...  
Keyword(s):  
Chemical Reactivity ◽  
Bond Cleavage ◽  
Degree Of Polymerization ◽  
Size Exclusion ◽  
Quinone Methide ◽  
Scanning Calorimetry ◽  
Good Thermal Stability ◽  
Maldi Tof ◽  
Flight Mass Spectrometry ◽  
Alkaline Conditions

Abstract A trimeric β-O-4 lignin model bearing a styrene unit was polymerized in the presence of azobisisobutyronitrile as an initiator of free radical polymerization. The polymer analysis achieved by size exclusion chromatography (SEC), 1H, 13C, 31P NMR, matrix-assisted laser desorption ionization combined with time-of-flight mass spectrometry (MALDI-ToF MS), differential scanning calorimetry, and thermogravimetry indicated its well-defined structure with good thermal stability at temperatures usually applied for alkaline pulping. SEC analysis proved a high degree of polymerization despite the size of the phenolic β-O-4 units in the polymer structure. MALDI-ToF spectrometry indicated that the polymer is composed of phenolic β-O-4 elements only. The chemical reactivity under alkaline conditions of the polymer was studied by both HPLC and 31P NMR. These two methods revealed two main concurrent processes, which include an oxidation of the phenol part followed by Cα-Cβ bond cleavage, and a formation of a quinone methide followed by its β-O-4 bond cleavage.

Thermal properties of a series of tetrafunctional fluorene-based oxazines/P-a blends

2016 ◽  
Vol 29 (10) ◽  
pp. 1139-1147 ◽  
Author(s):  
Zi Sang ◽  
Tiantian Feng ◽  
Wenbin Liu ◽  
Jun Wang ◽  
Mehdi Derradji
Keyword(s):  
Thermal Stability ◽  
Differential Scanning Calorimetry ◽  
Thermal Properties ◽  
Mechanical Analysis ◽  
Proton Nuclear Magnetic Resonance ◽  
Primary Amines ◽  
Resonance Spectroscopy ◽  
High Glass Transition Temperature ◽  
Scanning Calorimetry ◽  
Good Thermal Stability

A new series of aniline and aniline-mixed tetrafunctional fluorene-based oxazine monomers were synthesized using 2,7-hydroxy-9,9-bis-(4-hydroxyphenyl) fluorene, paraformaldehyde, and primary amines (including aniline or aniline mixed with n-butylamine or n-octylamine composition). Fourier transform infrared spectroscopy and proton nuclear magnetic resonance spectroscopy were used to characterize the structure of the monomers. The copolymers were obtained by adding the monomers into a typical monofunctional polybenzoxazine (phenol-aniline-based benzoxazine). Differential scanning calorimetry, thermogravimetric analysis, and dynamic mechanical analysis were performed to study the thermal properties of the copolymers. The copolymers exhibited high glass transition temperature values (164–201°C). A good thermal stability was also obtained with a 5% weight loss temperature over 355°C and high char yields at 800°C (42–50%).

scholarly journals Properties and structure of high temperature resistant cyanate ester/polyethersulfone blends using solvent-free toughening approach

2020 ◽  
Author(s):  
Lyaysan Amirova ◽  
Fabian Schadt ◽  
Markus Grob ◽  
Christian Brauner ◽  
Thomas Ricard ◽  
...  
Keyword(s):  
Molecular Weight ◽  
High Temperature ◽  
Network Formation ◽  
Mechanical Analysis ◽  
Solvent Free ◽  
Cyanate Ester ◽  
Low Molecular Weight ◽  
Scanning Calorimetry ◽  
Molecular Weights ◽  
The Difference

AbstractA high temperature resistant novolac cyanate ester was blended with polyethersulfone (PES) with different molecular weights using the solvent-free approach. The phase separation, curing behavior and thermal properties were studied using hot stage microscopy, differential scanning calorimetry and dynamic mechanical analysis. Results showed the difference in the morphology for blends with different molecular weight PES explained by possible network formation. The influence of PES content on the glass transition temperature and mechanical properties was investigated. The most significant toughening effect (increase of 132% in fracture toughness) was achieved on a functionalized low molecular weight PES (20 parts per hundred of resin, phr). Rheology investigation allowed to estimate the optimal content of PES (15 phr) for further prepreg manufacturing.

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