Przemysl Chemiczny, Vol.81, No.12, 785-791, 2002
Reactive extrusion - a modern trend in material engineering
Polish PET ([eta] = 0.65 dL/g) or PBT (MFR(270degreesC, 1.2 kg) = 5.4 g/10 min) and PA 6 (Tarnamid T-27) (MFR(230degreesC, 0.32 kg) = 2.6 g/10 min) were blended with ricinyl-2-oxazoline maleinate (ROM)-grafted LDPE (PE-g-ROM) at specified ratios. PIE (MFR (190degreesC, 2.16 kg) = 2.1 g/10 min) was mixed with ROM and an organic peroxide and extruded in 3 min from a Berstorff ZE-25-33D at 180-200degreesC to yield PE-g-ROM; the melt was cooled, granulated and dried 6-8 h in dry air at 85degreesC. The ROM had M = 430, n(D)(20) 1.4854, and b.p. >250degreesC/10 Pa. The grafted product was extracted (4% w/v) with boiling toluene, the extract was precipitated with MeOH, and dried 48 h at 75degreesC. The PBT and the PET blends were extruded at 210-230degreesC and 240-260degreesC, resp. FTIR spectra and microcalorimetric, mechanical and microscopic property data were measured. Grafting of polyolefins involved chain modifications caused by the melamine moiety of oxazoline and by the group containing the incorporated ricinyl-2-oxazoline compound. SEM photomicrographs disclosed a compatible heterogeneous stable structure in the blends. Block copolymers located at phase boundaries enhanced the compatibility of the components. As the PE-g-ROM content was increased, the solubility in HCOOH fell. The mechanical properties of the starting polymers were generally retained, but the blends' processing properties were better. 44 refs.