Evaluation of the glass transition temperature variability of carbon-fiber plastic produced by the autoclave molding method

2019 ◽  
Vol 9 ◽  
pp. 17-24
Author(s):  
P. S. Marahovskij ◽  
◽  
O. G. Ospennikova ◽  
D. Ya. Barinov ◽  
N. N. Vorobev ◽  
...  
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Carbon Fiber ◽  
Temperature Variability ◽  
Molding Method ◽  
Fiber Plastic ◽  
Carbon Fiber Plastic

Study of the effect of the reinforcement direction on the identification of relaxation transitions of moisture-saturated carbon fiber VKU-25

2021 ◽  
Vol 87 (9) ◽  
pp. 38-43
Author(s):  
O. G. Ospennikova ◽  
P. S. Marakhovsky ◽  
N. N. Vorobyov ◽  
E. V. Nikolaev ◽  
A. I. Gulyaev ◽  
...  
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Carbon Fiber ◽  
Polymer Matrix ◽  
Structural Parameters ◽  
Polymer Materials ◽  
Thermal Coefficient ◽  
Initial State ◽  
Relaxation Transitions

Thermodilatometric methods of analysis are used to study the structural parameters of polymer materials, however, when studying moisture-saturated compositions certain difficulties arise in their identification. The results of thermophysical tests of VKU-25 carbon fiber samples in the initial state and after moisture saturation are presented. It is shown that heat treatment of materials affects the recorded values of the glass transition temperature of the epoxy matrix. When the samples are exposed in water or above the water surface, the sorbate penetrates into the polymer at the same rate, which is confirmed by almost identical values of water absorption at the same exposure time. The estimates of the thermal coefficient of linear expansion (TCLE) of the samples in the range of 20 - 250°C are given. Moreover, it is shown that the glass transition temperature of the plasticized polymer matrix depends on the direction of fiber reinforcement. In the case of moisture-saturated carbon fiber (CF)heated to 210°C, the formation of main cracks occurs mainly at the fiber-matrix interface. The glass transition temperature (GTT) of the material in the dry state (176 - 177°C), appeared almost independent on the heating rate, whereas for water-saturated samples, GTT changes significantly and can be described by a polynomial of the 2nd order. After exposure of the carbon fiber under conditions of high temperature and humidity, two relaxation transitions corresponding to the systems occur in the polymer matrix: epoxidian oligomer— amine hardener and polyfunctional resin— amine hardener. The glass transition temperature is 132 and 159°C in the first and in the second, respectively. The results obtained can be used in the development of new polymer composite materials.

Evaluation of the Variability of Glass Transition Temperature of Carbon-Fiber-Reinforced Plastic Fabricated by Autoclave Molding

2020 ◽  
Vol 13 (1) ◽  
pp. 73-79
Author(s):  
P. S. Marakhovskii ◽  
O. G. Ospennikova ◽  
D. Ya. Barinov ◽  
N. N. Vorob’ev ◽  
S. Yu. Shorstov ◽  
...  
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Carbon Fiber ◽  
Carbon Fiber Reinforced Plastic ◽  
Fiber Reinforced ◽  
Fiber Reinforced Plastic ◽  
Reinforced Plastic ◽  
Carbon Fiber Reinforced

scholarly journals Deformation Resistance Performance of Carbon Fiber-Reinforced Plastic Machined by Controlling Drilling Area Temperature below the Glass Transition Temperature

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1394
Author(s):  
Chenping Zhang ◽  
Xiaohui Zhang ◽  
Yugang Duan ◽  
Yu Xia ◽  
Yueke Ming ◽  
...  
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Carbon Fiber ◽  
Cryogenic Treatment ◽  
Deformation Resistance ◽  
Cryogenic Machining ◽  
Fiber Reinforced ◽  
Machining Performance ◽  
Carbon Fiber Reinforced

Drilling of carbon fiber-reinforced plastics (CFRPs) is a challenging task in aviation and aerospace field. Damages, which can reduce the strength of the structure, often occur during secondary machining operations due to the applied cutting force and generated heat. The main objective of this study was to investigate the drilling performance and the deformation resistance of CFRPs subjected to cryogenic treatment based on glass transition temperature (Tg). Therefore, a cryogenic machining approach was adopted by fixing the workpiece inside a cryogenic box to drill CFRPs. The machining performance was briefly evaluated. Moreover, a through-hole drilling method was promoted to analyze the mechanism of different deformation mechanical properties. The results showed that the cryogenic machining approach improved the machining performance of CFRPs. Nevertheless, the residual intensity of cryo-treated specimen decreased (about 7.14%) due to the Tg-based viscoelasticity. These results demonstrate the great potential of this approach in advanced industrial applications and further pave the way for efficient secondary machining operation of CFRP components.

Effect of locally deposited nanosilica particles on interlaminar fracture toughness of high glass-transition temperature epoxy carbon fiber-reinforced composites

2019 ◽  
Vol 53 (25) ◽  
pp. 3599-3614 ◽  
Author(s):  
Bryan M Louis ◽  
Florian Klunker ◽  
Paolo Ermanni
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Carbon Fiber ◽  
Fracture Energy ◽  
Composite Laminates ◽  
Particle Distribution ◽  
Fiber Reinforced ◽  
High Glass Transition Temperature ◽  
Nanosilica Particles

This study explores the toughening of fiber-reinforced composite laminates to prevent against mode 1 delamination by using a selective placement of nanosilica particles in only the out-of-tow interlaminar regions of the laminate. In place of a conventional homogenous particle distribution throughout the laminate, “selective toughening” through controlled particle deposition is examined with the objective to increase the nanosilica toughening efficiency. Using a laboratory-scale manufacturing route conceptually similar to a combined prepreg and resin-film process, uni-directional carbon fiber composite laminates containing high glass-transition temperature amine-cured Dow D.E.R. 330 epoxy are produced from both particle distribution configurations. Comparisons are made by double cantilever beam testing for mode 1 delamination fracture energy G1C and by examination of the fracture surfaces. The results show that further nanosilica toughening efficiency is possible with local deposition and toughening compared to the conventional homogenous particle distribution throughout the laminate. For the same total nanosilica particle content in the laminate, the delamination toughening effects are maintained or improved when locally toughened in only the out-of-tow interlaminar regions. For mode 1 delamination initiation and propagation, fracture energy increases in the range of 60% over the untoughened laminates are found for the laminates with a local particle distribution. By comparison, those laminates with a conventional homogeneous particle distribution saw increase of 20–35% over the untoughened laminates. The implications of the localized toughening approach are discussed to provide further guidance in optimizing the use of nanosilica particles and particle toughening in general in composite laminates.

Resistive Heating of Carbon Fiber Aided Rapid Curing of Vacuum Assisted Resin Infusion Molding

2014 ◽  
Vol 1030-1032 ◽  
pp. 170-173 ◽  
Author(s):  
Kao Min Zhang ◽  
Yi Zhuo Gu ◽  
Min Li ◽  
Shao Kai Wang ◽  
Zuo Guang Zhang
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Carbon Fiber ◽  
Cycle Time ◽  
Rapid Heating ◽  
Water Cooling ◽  
Cooling Process ◽  
Resistive Heating ◽  
Processing Cycle

A kind of rapid heating method which takes advantage of carbon fiber conductivity to shorten the cycle time of VARIM was designed in present paper. The processing cycle time, curing degree, glass transition temperature and mechanical properties of the laminates fabricated by carbon fiber internal resistive heating aided VARIM (R-VARIM) were studied. The results revealed that the cyle time of R-VARIM with con-water cooling process is only 450s, it is about 52% lower than that of previous study. Lower cooling rate before glass transition temperature is useful to complete cure of resin and improve the properties of the composites.

THE INFLUENCE OF CLIMATIC AGEING ON THE PROPERTIES OF PCM-BASED EPOXY RESIN SYSTEMS

2021 ◽  
pp. 128-136
Author(s):  
A.A. Evdokimov ◽  
◽  
A.P. Petrova ◽  
K.A. Pavlovskiy ◽  
I.N. Gulyaev ◽  
...  
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Carbon Fiber ◽  
Epoxy Resin ◽  
Modulus Of Elasticity ◽  
Vinyl Ester ◽  
Mechanical Characteristics ◽  
Subtropical Climate ◽  
Physical And Mechanical Characteristics

The article presents the results of studies of the properties of carbon fiber of the VKU-51 brand and fiberglass of the VPS-58 brand, made on the basis of the epoxy vinyl ester binder of the VSV-43 brand, after exposure in full-scale conditions of moderate and subtropical climate for 5 years with intermediate removals after 1 and 3 years. Physical and mechanical characteristics (strength and modulus of elasticity under tension, compression and bending) and glass transition temperature are determined. Studies have shown a high preservation of properties at 20 °C: 90–100% in VKU-51 and 73–100% in VPS-58, depending on the type of test.

scholarly journals Study on Toughness Improvement of a Rosin-Sourced Epoxy Matrix Composite for Green Aerospace Application

2020 ◽  
Vol 4 (4) ◽  
pp. 168
Author(s):  
Dongyuan Hu ◽  
Xvfeng Zhang ◽  
Xiaoling Liu ◽  
Zhen Qin ◽  
Li Hu ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Carbon Fiber ◽  
Matrix Composite ◽  
Resin Matrix ◽  
Potential Candidate ◽  
Interlaminar Fracture Toughness ◽  
Interlaminar Fracture

A high temperature epoxy resin was formulated by using a rosin-sourced anhydride-type curing agent, i.e., maleopimaric acid (RAM), and a two-component epoxy consisting of an E51-type epoxy and a solid phenolic epoxy to form a bio-sourced green matrix resin. The glass transition temperature of the final resin was 238 °C Carbon fiber composite prepreg and was manufactured and laminated into composite specimens. Interleaving Toughening Technology (ITT) was applied to the laminates by using Polyamide interleaf veils. The interlaminar fracture toughness and compression after impact (CAI) strength were investigated and showed that the opening Mode I interlaminar fracture toughness GIC and the Mode II interlaminar fracture toughness GIIC of the specimens with interleaves were significantly improved from 227.51 J/m2 to 509.22 J/m2 and 1064.3 J/m2 to 1510.8 J/m2, respectively. Correspondingly, the drop-weight impact test shows that the interleaves reduced the impact damage area from 20.9% to 11.3% of the total area, and the CAI residual strength was increased from 144 MPa to 191 MPa. Meanwhile, mechanical tests showed that the in-plane properties of the interleaved laminates were slightly reduced due to carbon fiber volume fraction reduction. In conclusion, the high glass transition temperature, fracture toughness and CAI behaviour make the green resin matrix composite a potential candidate for aerospace applications.

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