Abstract: A terpolymer containing propylene, ethylene and 1-hexene wherein: (i) the content of 1-hexene derived units ranges from 1 wt % to 2.6 wt %; (ii) the content of ethylene derived units is higher than 0.7 wt % and fulfils the following relation (1): C2<C6?0.2 ??(1) wherein C2 is the content of ethylene derived units wt % and C6 is the content of 1-hexene derived units wt %; (iii) the melt flow rate (MFR) (ISO 1133 230° C., 2.16 kg) ranges from 0.5 to 3.9 g/10 min; (iv) the melting temperature ranging from 130° C. to 138° C.; preferably from 132° C. to 136° C.

Abstract: A propylene and 1-hexene copolymer containing from 0.5 wt % to less than 5 wt % of 1-hexene derived units said copolymer having: a) a melting point higher than 145° C.; b) a melt flow rate (MFR2) determined according to ISO method 1133 (230° C., 2.16 kg ranging from 10 dl/10 min to less than 60 dl/10 min; said copolymer being chemically degradated to MFR2 and wherein the ratio MFR2/MFR1 is comprised between 15 and 56; wherein MFR1 is the melt flow rate measured according to ISO method 1133 (230° C., 2.