Method for monitoring Tg of polymer-based composite material by using carbon nano-paper sensor

Abstract

The invention belongs to the technical field of characterization of polymer properties, and particularly relates to a method for monitoring a Tg (glass-transition temperature) of a polymer-based composite material by using a carbon nano-paper sensor. The method comprises the following steps: fixing four copper conductors on the surface of rectangular carbon nano-paper to form a carbon nano-paper sensor; embedding the sensor into a prepreg of a polymer-based composite material to be monitored; performing curing molding according to a standard curing process of the prepreg of the polymer-based composite material so as to obtain the polymer-based composite material; heating the composite material again; and measuring the resistance of the carbon nano-paper sensor in the composite material by using a four-probe resistance measuring meter so as to obtain a resistance variation-temperature relation curve of the carbon nano-paper sensor during heating of the composite material after curing molding, wherein a resistance variation catastrophe point of the curve is the glass-transition temperature of the composite material. The method provided by the invention is simple and convenient in measuring process, is feasible, and is low in sensor and demodulating system cost; and most importantly, the method can achieve real-time online monitoring of a molding process of a composite material in the field of engineering application.

Description

Technical field [0001] The invention belongs to the technical field of polymer performance characterization, and specifically relates to a method for monitoring the Tg of a polymer-based composite material by a carbon nano paper sensor. Background technique [0002] Glass transition temperature (Tg) is an important characteristic parameter of polymer materials, which determines the temperature of use of the material. The mechanical properties of polymer matrix composites depend on their use temperature. At Tg, the thermodynamic, volume, optical, and electrical properties of the polymer will change significantly, so Tg is very important. [0003] The current methods used to monitor the Tg of polymer composites mainly include Differential Scanning Calorimetry (DSC), Dynamic Thermodynamic Analysis (DMA), Dielectric Relaxation (DRS) and Nuclear Magnetic Resonance (NMR). The equipment investment is relatively high, and at the same time, the size and weight of the tested sample are requ...

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Problems solved by technology

[0003] At present, the methods used to monitor the Tg of polymer composites mainly include differential scanning calorimetry (DSC), dynamic thermodynamic analysis (DMA), dielectric relaxation method (DRS) and nuclear magnetic resonance (NMR). The equipment investment is high, and there are requirements for the size and weight of the tested sample, so it is impossible to monitor the Tg of the polymer-based composite material production process online in real time

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