Crushing strength of PVA–PS and PVA–MPS gel beads.

Sample	Time (h)
	Retention rate (%)
	4	5	6	7	8	9	10	11	12
PVA–PS	100	100	100	100	100	100	94	82	76
PVA–MPS	100	100	100	100	100	100	100	100	100