FLAME RETARDANTS

In terms of Izod impact , all of the brominated FR formulations exhibited high initial results compared to non- FR compound , in the range of about 10 %, while the non-halogenated FR showed a 40 % decrease . Similar trends were seen in all five recycling cycles ( Figure 1a ) Looking at tensile strength , the brominated epoxy-based formulations , with or without ATO , showed similar initial strength compared to the non- FR one . Brominated PS formulations , with and without ATO , exhibited a 10 % decrease compared to the non-FR one . DEPAL-related values were 25 % lower ( Figure 1b ).

PBT

The methodology employed with UL-94 V0 GFR PBT was identical to the one used for the aforementioned PA 6,6 compounds . Six 30 % GFR PBT formulations were tested with exactly the same contents . Brominated polyacrylate showed a higher Izod impact strength at all stages of the experiment , higher even than the one achieved by the non-FR formulation . The DEPAL FR showed a 40 % decrease for the initial compound and the first recycling round , and further recycling cycles could not be performed any further ( Figure 2a ). The brominated epoxy-based formulation , with or without ATO , was shown to have 10 % higher strength than the non-FR one , throughout all of the cycles . The FR values of the DEPAL formulation were 50 % lower and the material could not be taken beyond the first recycling round ( Figure 2b )

ABS

Following the same methodology , UL-94 V0 ABS compounds were evaluated for the resilience of their mechanical properties , i . e . heat deflection temperature ( HDT ) and spiral flow , by comparison with virgin material . The FRs used were a brominated epoxy polymer with a MW of 2,300 , and brominated triazine The HDT decrease for both FRs through the five recycling cycles was minor , less than 30 º C ( Figure 3a ). The increase in spiral flow ( expressed in inches ) confirms that the flame retarded ABS compound maintain good flowability properties throughout the monitored recycling process ( Figure 3b ).

Conclusions

Brominated FRs not only allow mechanical recycling over several cycles , they also contribute to maintain critical mechanical properties at high values over time . •

INCH

26

24

22

Virgin

Brominated epoxy polymer

Epoxy

Polymer

Brominated triazine Triazine