Effect of solid state shear milling on structure and properties of poly(vinyl alcohol)/shell powder composite prepared by thermal processing

In this paper, a novel poly(vinyl alcohol) (PVA)/shell powder composites were prepared by the combination of Solid State Shear Milling (S3M) technology and thermal processing technology of PVA, and the effects of S3M on the structure and properties of the composites were systematically studied. Ascribing to the strong shearing, crushing and mixing functions of S3M technology, the ultrafine pulverization and the activation of shells were achieved, making more Ca2+ and CO32− of shells exposed and interacted with the hydroxyl groups of PVA, thus resulting in the good dispersion as well as the highly filling content of shell powders (Up to 70 wt%) in PVA matrix. The enhanced interactions also inhibited the elimination reaction of the hydroxyl groups of PVA, leading to the increase of the initial thermal degradation temperature of the composite, and simultaneously improved the compatibility between PVA and fillers, making shell powders played a better reinforcing effect on PVA, so endowed the composite with better mechanical properties. When shell powder content reached 50 wt%, the tensile strength of the composite was 39 MPa, about 21 MPa higher than the composite prepared by directly melt blending.