Assertion: lignin's structure | /r/CapableOf | enhance physical properties
Facets:
Source sentences:
text: The following reasons explained the enhancement of the physical behaviors: (1) plasticized lignin decreases the cross-linking density of LPUFs, which increases the apparent density and compressive strength (Zhang et al. 2015); (2) the natural rigid structure of lignin may disrupt the macromolecular structure, which decreases the elongation and enhances the physical properties (Putz et al. 2008); (3) the hydrogen bonding between –NH and –C=O in LPUFs may cause a decrease in elongation, and Huang and Lai (1997) established that an increase in the hydrogen bonding index can increase the modulus and decrease the maximum elongation of LPUFs; and (4) the imbalance between the gel and foaming rates is caused by the excessive lignin content in the synthesis process, which leads to a decrease in the cross-linking density and seriously affects both the compressive and specific compressive strengths.