Materials, Processing, and Characterization Techniques

Recycled PET from beverage bottles (type FR 65, supplied by Rethmann Plano GmbH) (as reinforcing component) and commercial grade PP (type Novolen with MFI 5, provided by Basell) (as matrix), as well as a compatibilizer (C) (ethylene-glycidyl methacrylate (E-GMA), type Lotader AX 8840, commercial product of Atochem) were used. 

From the dried components, various PET/PP/C blends (in wt. ratios40/60/0 40/59/1,40/57/3,40/54/6, and 40/51/9) were prepared and processed on a Brabender twin-screw extruder. The extrudate was cooled down to a temperature of75-80 °C before it was continuously drawn to a draw ratio of about 10-12. Part of the drawn bristles (diameter of 0.6-0.7 mm) was pelletized for injection molding experiments. 

All blends, as well as the neatPP, were processed by compression molding (CM) or by injection molding (IM). The IM was performed on a lab-scale Babyplast machine produced by Cronoplast S.L., Barcellona, at temperatures being either about 25-30 C below or above of PET. 

For the preparation of another set of MFC samples, amorphous PPE and four different kinds of thermotropic LCPs were used. Table 1 lists some of the 

It should be pointed out here that the set temperatures were lower by about 30-40 °C than the of the LCP types 2,3, and 4, but by ca. 20 °C higher than the Tn, of 1- LCP because of the relatively high processing temperature required for PPE (ca. 290-300 °C). i.e., the blends containing 1-LCP were processed at a temperature higher than its T. Test samples with dimensions 4 x 10 x 80 mm were prepared from all drawn blends and neat polymers. 

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