Table 1. Table of HDPE/PPR Piping Formulations.

formulation code name	HDPE/PPR	POE-g-MAH grafted compatibilizer (test group)	non-POE-g-MAH compatibilizer (control group)	CaO defoamer
non-recycled HDPE/PPR	95			5
5% w POE-g-MAH	90	5		5
15% w POE-g-MAH	80	15		5
25% w POE-g-MAH	70	25		5
35% w POE-g-MAH	60	35		5
45% w POE-g-MAH	50	45		5
55% w POE-g-MAH	40	55		5
5% w/o POE-g-MAH	90		5	5
15% w/o POE-g-MAH	80		15	5
25% w/o POE-g-MAH	70		25	5
35% w/o POE-g-MAH	60		35	5
45% w/o POE-g-MAH	50		45	5
55% w/o POE-g-MAH	40		55	5