Dynamic mechanical analysis of storage modulus development in light-activated polymer matrix composites

ABSTRACTThe results of modulus measurements, on carbon black-filled poly(N-vinylpyrrolidone), using dynamic mechanical analysis and nanoindentation were compared. It was shown that beyond the critical pigment volume concentration for this composite system (∼ 25 vol% carbon black), the storage modulus, obtained with dynamic mechanical analysis, decreased with increasing filler concentration. This dropping modulus was due to porosity that developed in the composite films when the critical pigment volume concentration had been exceeded. Elastic modulus obtained with nanoindentation showed the opposite trend, with modulus increasing with additional carbon black loading. An analysis of the method used to calculate modulus based upon indentation data was performed and a mechanism was proposed to explain the disparity between the moduli obtained using these two different methods of measurement.

Download Full-text

Dynamic mechanical behaviour of kevlar and carbon-kevlar hybrid fibre reinforced polymer composites

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1177/0954406220970600 ◽

2020 ◽

pp. 095440622097060

Author(s):

Pragati Priyanka ◽

Harlal Singh Mali ◽

Anurag Dixit

Keyword(s):

Glass Transition ◽

Transition Temperature ◽

Glass Transition Temperature ◽

Dynamic Mechanical Analysis ◽

Storage Modulus ◽

Composite Laminates ◽

Mechanical Analysis ◽

Textile Composites ◽

Elastic Behaviour ◽

Dynamic Mechanical

Comprehensive experimental results of dynamic mechanical analysis (DMA) of polymer reinforced textile composites are presented in the current investigation. Plain and 2x2 twill woven multilayer fabrics of monolithic kevlar and hybrid carbon-kevlar (C-K) are reinforced into the thermoset polymer matrix. Kevlar/epoxy and C-K/epoxy composite laminates are fabricated using an in-house facility of the vacuum-assisted resin infusion process. Variation of the visco-elastic behaviour (storage modulus, damping factor and glass transition temperature, Tg) along with time, temperature and frequency is studied for the composites. Dynamic mechanical analysis is performed under temperature sweep with frequency ranging from 1-50 Hz. Results depict the effect of inter yarn hybridisation of carbon with kevlar yarns on the storage modulus, damping performance, and creep behaviour of dry textile composites. Temperature swept dynamic characterisation is also performed to evaluate the degradation and damping performance of the composite laminates soaked in the deionised water at glass transition temperature Tg, ½ Tg, and ¾ Tg. The morphological study has been performed post the dynamic mechanical analysis using field emission scanning electron microscope.

Download Full-text

Influence of Graphene Oxide Functionalization Strategy on the Dynamic Mechanical Response of Natural Fiber Reinforced Polymer Matrix Composites

Characterization of Minerals, Metals, and Materials 2021 - The Minerals, Metals & Materials Series ◽

10.1007/978-3-030-65493-1_3 ◽

2021 ◽

pp. 29-36

Author(s):

Fabio Da Costa Garcia Filho ◽

Michelle Souza Oliveira ◽

Fernanda Santos da Luz ◽

Sergio Neves Monteiro

Keyword(s):

Graphene Oxide ◽

Polymer Matrix ◽

Mechanical Response ◽

Natural Fiber ◽

Polymer Matrix Composites ◽

Fiber Reinforced Polymer ◽

Matrix Composites ◽

Fiber Reinforced ◽

Dynamic Mechanical ◽

Reinforced Polymer

Download Full-text

Comparative investigation of physical, mechanical and thermomechanical characterization of dental composite filled with nanohydroxyapatite and mineral trioxide aggregate

e-Polymers ◽

10.1515/epoly-2016-0319 ◽

2017 ◽

Vol 17 (4) ◽

pp. 311-319 ◽

Cited By ~ 4

Author(s):

Anoj Meena ◽

Harlal Singh Mali ◽

Amar Patnaik ◽

Shiv Ranjan Kumar

Keyword(s):

Compressive Strength ◽

Dynamic Mechanical Analysis ◽

Storage Modulus ◽

Water Sorption ◽

Mineral Trioxide Aggregate ◽

Mechanical Analysis ◽

Comparative Investigation ◽

Dental Composite ◽

Dynamic Mechanical

AbstractThis study presents comparative investigation of adding nanohydroxyapatite (HA) (5–20 wt.%) and mineral trioxide aggregate (MTA) (5–20 wt.%) on the physical, mechanical and thermomechanical characterization of dental composite. The performances of both experimental composites were assessed through various physical, mechanical and thermomechanical tests such as void content test, microhardness test, compressive strength test, dynamic mechanical analysis and thermogravimetric analysis. The result of experiment indicated that the addition of 5 wt.% of HA increased the water sorption, hardness and compressive strength by 50.47%, 13.46% and 62.35%, respectively, whereas the addition of 5 wt.% of MTA increased the water sorption, hardness and compressive strength by 19.23%, 100% and 5.44%, respectively. Dynamic mechanical analysis results revealed that the addition of 5 wt.% HA increased the storage modulus by 10.21%, whereas the addition of 5 wt.% of MTA decreased the storage modulus by 11.79%. The filler HA proved to be better choice in term of thermal stability behavior as compare to MTA filler.

Download Full-text