Assertion: polypropylene's use | /r/HasProperty | found for the polymer
Facets:
value: because of brittleness
type: CAUSE
value: because of crazing
type: CAUSE
value: as late as
type: TEMPORAL
Source sentences:
text: As late as 1930 little commercial use had been found for the polymer because of brittleness and crazing (minute cracking), which were caused by impurities that brought about the cross-linking of the polymer chains.