No abstract

No abstract

The contact area between the filler and the polymer is a critical region that influences to a great extent the filler–matrix adhesion and therefore the mechanical properties of the composite. Controlling the type of interactions at this interface has a significant effect on the properties of the composite materials. In this context, we prepared composites by covalent reaction of diazonium‐functionalized zeolite with phenol‐formaldehyde resin. Introducing the hydroxymethyl groups onto the surface of the filler via diazonium chemistry allows for covalent bonds between the resin and the modified filler. Such a modification resulted in higher flexural strength of the composites, better ability to dissipate mechanical energy during load and also better damping properties (which are strongly linked to the final product durability) compared with the composites bearing pristine zeolite filler. Moreover, application of modified filler accelerates the crosslinking of novolac resin used as a binder in abrasive tools. One key feature of the work was brought by thermogravimetric analysis–mass spectrometry results which indicate no release of toxic urotropine degradation products for composites containing modified fillers. This work demonstrates conclusively that diazonium‐functionalized zeolite filler particles improve remarkably the thermal and mechanical properties of novolac‐based composites. Such robust composites have high potential in the production of novel abrasive tools. POLYM. COMPOS., 40:3209–3219, 2019. © 2018 Society of Plastics Engineers

No abstract

Structural and morphological properties of pure and F-doped or Sb-doped particles of tin oxide were studied by X-ray diffraction and transmission electron microscopy (TEM). A typical polycrystalline diffraction pattern corresponding to the tetrahedral phase was obtained for all the particles independently of the doping. No peaks matching any antimony oxide phase were observed; thus, it is probable that Sb replaces Sn in the tin oxide lattice. Doping with antimony results in a lattice parameter increase of the SnO 2 /Sb phase, which might be related to the geometrical distortion of the lattice due to the replacement of Sn by Sb. Moreover, the SnO 2 /Sb sample exhibited a preferential orientation in the (110) and (101) planes. The TEM analysis showed that all the tin oxide particles are agglomerated and form aggregates and networks leading to a mesoporous structure with different pore sizes. The particles have a spherical shape and sizes between 5 and 20 nm in average. All particles were well crystallized with nicely visible lattice fringes in the high-resolution HRTEM images.