Solid materials with dipolar molecules

I am trying to heat solids using controlled microwave radiation and I am therefore looking for materials that absorb microwaves well. I have understood that for radiation in the radio frequency and microwave frequency regimes the polarity of molecules and the conductivity are most important.
I am also reading this chapter about dry solids (A. C. Metaxas & R. J. Meredith. *Industrial Microwave Heating*. 1983.):



> 
> ##### 2.8 Dry, non-conducting dielectrics
> 
> 
> Emphasis has been given so far to the conducting phase in dielectrics such as, for
> example, water, because high frequency heating has been applied very successfully
> to many drying applications. However, many applications require heating of dry,
> non-conducting insulators such as natural rubber or other chemical substances,
> in order to achieve specific reactions within the material. In this case, Maxwell—
> Wagner type effects, in the absence of any trace impurities, play no part at all in
> the heating process which is now governed solely by dipolar effects. In fact, if the
> insulating material is non-polar, one may deliberately introduce a controlled proportion
> of conducting particles, such as carbon black, to enhance the absorption
> of the applied high frequency energy by the material to be heated. This is discussed
> further in Section 3.9.
> 
> 
> 


From this section I understand that it's possible to mix carbon into materials that are non-polar and non-conductive to make them absorb microwaves and I feel like this would be the case if I want to heat plastics for example. But my question is: are there (common) solids that are non-conductive but have polar molecules, so that they would also be suitable for microwave heating? And could they potentially have a higher absorption than conductive materials?


And does anyone know of any other absorbent solids?


I am thankful for any help!




Though not a material consisting of individual molecules like e.g., glucose, try silicon carbide ($\ce{SiC}$).


This material not only became popular because it is a good absorber of microwave reaction, but equally because of its high mechanical strength, high melting point, and low chemical reactivity. These render $\ce{SiC}$ you might heard about earlier (abrasives, pads for breaks, heat filaments, etc.) suitable for (small) chemical reactors, too.


[![enter image description here](https://i.stack.imgur.com/IJ7ga.png)](https://i.stack.imgur.com/IJ7ga.png)


(taken from an overview by [Anton Paar](https://wiki.anton-paar.com/en/silicon-carbide-sic/))


[![enter image description here](https://i.stack.imgur.com/2039Q.png)](https://i.stack.imgur.com/2039Q.png)


(Kappe, *Acc. Chem. Res.* **2013**)


Since it is equally commercially available as shot and powder, you could blend it as a dispersion into a solid matrix, too. Then, $\ce{SiC}$ were the antenna heating from inside of your sample.


Kappe, C. O. Unraveling the Mysteries of Microwave Chemistry Using Silicon Carbide Reactor Technology. *Acc. Chem. Res.* **2013**, *46*, 1579–1587; [doi 10.1021/ar300318c](https://doi.org/10.1021/ar300318c).


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