Basalt Fiber-Reinforced Polymer Blends

Our study was extended to BF-reinforced blends containing non-polar PP/polar PA12 polymers. The strategy with this polymer pair was to coat and encapsulate the BF in situ by the polar PA 12 and disperse it in the PP matrix. This in situ formed coating was expected to rise the resistance of BF against fracture during compounding. As PA 12 and PP are incompatible, a compatibilizer, maleated PP (PP-g-MAH), was added. The PA 12 content of the blends was varied between 0 and 50 wt.% in 10 wt.% steps, whereas the amount of PP-g-MAH was kept constant (5 phr parts per hundred resin). The BF content was also varied between 0 and 20 wt.% in 10 wt.% steps (Table 4). 

Hybrid composites were produced by extrusion melt compounding and dumbbell specimens were injection-molded for testing. Specimens were subjected to static and dynamic flexural tests using the 3-point bending configuration. Static tests were carried out at a deformation rate of 2 mm/min, whereas dynamic ones at 2.9 m/s, both at room temperature. In addition, the and values were determined. The a, E, and K data are summarized in Table 5. 

The results show that for the plain PP matrix the strength decreases with increasing BF content. This leads to a conclusion that during processing BFs break into pieces shorter than the critical length, hence they are present as fillers in the 

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