The response of carbon black filled high-density polyethylene to microwave processing

Synthesis and processing of biodegradable and bio-based polymers by microwave irradiation

“…Even if, commonly, homogeneous heating represents a topic feature of microwave devices it should be noted that highly dielectric materials rapidly diminish the incident radiation intensity, hence recourse to large volumes may cause shielding effects and colder matter at the core. This is the reason why "penetration depth", defined as the point where only 37% (1/e) of the incident MW radiation is still present and calculated as the reciprocal of loss control represents a critical engineering point: some authors (F. Liu et al, 2010;Sharma & Mishra, 2010) still choose to perform the measure immediately after microwave exposure (even a conventional thermometer may be used in this case), however a real-time monitoring is usually favored, nowadays, in order to operate a more accurate control. Three configurations are adopted in the vast majority of the reported examples: at a laboratory scale (industrial application is dampened by their cost and fragility) the preferred and most affordable probes seem to be fiber-optic thermometers inserted in the reaction mixture using transparent tubes.…”

“…According to several authors, microwave foaming under vacuum (Jaja & Durance, 2008) or at atmospheric pressure (Torres et al, 2007) proved to be an effective route to obtain porous materials for tissue engineering applications from polymeric gels. It is worth reminding that microwave transparent polymers, such as HDPE, may easily be processed employing microwaves as energy source in the presence of highly absorbing fillers and additives like carbon black (F. Liu et al, 2010). Theoretical models have also been developed to investigate the optimal conditions for an efficient heating: in a recent study the application of microwaves on natural rubber and Nylon 66 slabs was analyzed highlighting the role of irradiation pulsing parameters and ceramic support plates (Durairaj & Basak, 2009).…”

Comparative study between the microwave heating efficiency of carbon nanotubes versus multilayer graphene in polypropylene nanocomposites

“…The presence of these inclusions strongly influence on the interaction of composite material with the microwave radiation. Some examples of these conductive additives include carbon black 5,6 , metal fibres 7 , silicium carbide 8 , titanium dioxide and others 9 . The effect of conductive additives on microwave heating depends on the size, shape, concentration, electrical conductivity and dielectric properties of the inclusions and their distribution in the matrix.…”

Numerical simulations of residual stress and inhomogeneous conductivity effects in CNT-filled resins cured by electric field

“…Compared with conventional external heating, it has been reported that internal heating leads to improved mechanical properties [4][5][6][7], adhesive bonding [8], and heating efficiency, as well as shorter curing cycles [9][10][11]. It is possible to increase the amount of heat generated by internal heating, such as microwave or Joule heating, by adding conductive fillers like carbon nanotubes (CNTs) [12][13][14] or carbon black [15] to the uncured thermosetting resin. At the same time, the inclusion of nanofillers leads to superior mechanical, conductive [16][17][18], and dielectric [19] properties compared with neat resins [20][21][22][23].…”