The aim of the present work is to study the properties of blends of Polypro
pylene (PP) with virgin and recycled high density polyethylene (r-HDPE) (80
/20), functionalized and non-functionalized EPR (5 wt%), and calcium carbon
ate (30%) as it is untreated or treated with a 1% by weight of coupling tit
anate agent. The mechanical behavior of PP/HDPE/EPR blends showed that func
tionalization was not effective. When blends of PP/HDPE/EPR with treated or
untreated filler were compared to the equivalent ones, but with recycled H
DPE and untreated filler, a slight increase was observed in elongation at b
reak and a decrease in Young's modulus and impact strength. This behavior m
ay suggest that recycled HDPE and EPR together act as a plastifier in these
blends. It was also found that the use of treated calcium carbonate did no
t contribute to obtain better mechanical properties. From these results it
can be concluded that it is possible to recycle HDPE in blends with PP and
non-functionalized EPR (nf-EPR), using untreated calcium carbonate as a fil
ler, and that this offers economic advantages and produces a material with
mechanical properties comparable to those of the compounds of PP with fille
r. (C) 1999 Elsevier Science Ltd. All rights reserved.