Photodegradation of UHMWPE Compounded with Annatto and Beetroot Extracts

Table 2

Properties obtained in tensile tests.

Sample code	Rupture strain (%)	Yield strength (MPa)	Elastic modulus (MPa)
Neat UHMWPE
Unexposed	806 37.1	16.3 0.2	128.4 5.8
21 days UV exposed	839 80.1	19.6 0.3	239.3 14.1
42 days UV exposed	14.6 1.7	20.2 1.0	321.3 14.1
UHMWPE with annatto
Unexposed	589.0 153.4	15.9 0.4	109.3 9.0
21 days UV exposed	578.0 44.8	17.8 0.6	174.0 11.5
42 days UV exposed	43.7 7.8	17.1 0.6	226.8 9.1
UHMWPE with beet
Unexposed	852.5 48.6	15.7 0.3	110.0 4.8
21 days UV exposed	848.7 78.5	16.4 0.2	130.4 5.7
42 days UV exposed	843.2 47.1	17.1 0.2	154.6 9.6

In fact the specimens ruptured before yielding. Localized yielding due to multiple cracks.