Assertion: lignin's unit | /r/HasProperty | linked with the polyol
Facets:
value: during the premixing stage
type: TEMPORAL
Source sentences:
text: This information, coupled with the quantitative determination of the different classes of hydroxyl contents (Table 2), suggests that either lignin hydroxyl units cross-linked with the polyol during the premixing stage or, in spite of thorough washing, trace amounts of polyol were detected in all of the lignin samples, which affected the concentration of hydroxyls in the lignin.