Enhanced mechanical performances of waterborne polyurethane loaded with lignosulfonate and its supramolecular complexes

Abstract

ABSTRACT:The modified waterborne polyurethane (WPU) with enhanced mechanical properties has been prepared after introducing lignosulfonate calcium (LS). Meanwhile, the LS was associated with WPU component by chemical grafting and/or physical attraction and hence produced a star-like network with LS and its supramolecular complexes as center. Especially, when the LS content was 1.5 wt %, the strength and elongation of WPU/LS blends (WLS) simultaneously increased. At this time, the center of network was dominated by the single molecules of spherical LS. Thereafter, with the increase of LS content, the strength of WLS blends increased unceasingly up to 6.0-7.5 wt % of LS loading while the elongation gradually decreased. Because the LS tend to aggregate as supramolecular complexes spontaneously, the center of network was gradually replaced by the LS supramolecular complexes. The structural changes of WLS blends were characterized by FTIR, DSC, and DMA. The results suggested that the LS component was mostly fused with hard-segments of WPU component and hence induced the formation of physical interaction, importantly for hydrogen bonding, depending on the compulsive association of chemical grafting and the impulse of similar hydrophilicity between the hard-segment and LS.

Phase behavior, interaction and properties of acetic acid lignin-containing polyurethane films coupled with aminopropyltriethoxy silane

“…The losspeak height represents the loss energy required by the motion of frozen segments [31]. It is consistent with the enhanced elongation and decreased Young's modulus, that is, higher toughness [42]. As a result, LPUSi2 and LPUSiT films are endowed with better toughness.…”

Physical and functional characterization of active fish gelatin films incorporated with lignin

“…It is a complex polydisperse natural polymer made up of phenyl-propane (C6ÀC3) units that bind cellulose fibres together, thus hardening and strengthening the plant cells. Lignin derivatives have been incorporated as fillers in different synthetic polymer matrices to develop lignin-based materials with improved physical properties (Cui, Xia, Chen, Wei, & Huang, 2007;Feldman, Lacasse, & Beznaczuk, 1986;Kadla & Kubo, 2003;Mishra, Mishra, Kaushik, & Khan, 2007). During the last decade, a great deal of research was devoted to the development of lignin-containing biopolymeric materials, on account of its renewable, non-toxic and biodegradable character (Ban, Song, & Lucia, 2007;Baumberger, Lapierre, Monties, Lourdin, & Colonna, 1997;Chiellini, Cinelli, Fernandes, Kenawy, & Lazzeri, 2001;Julinová et al, 2010;Li & Sarkanen, 2002;Vengal & Srikumar, 2005;Wu, Wang, Li, Li, & Wang, 2009).…”

Structure and properties of poly(butylene succinate) filled with lignin: A case of lignosulfonate

“…In this study, lignosulfonate calcium (LS), a water-soluble polydisperse polyelectrolyte with high rigidity, was selected as a natural filler to improve the performance of a PBSbased material. Because of its easy availability, low cost, and many kinds of active groups, 28,29 the introduction of LS as the filler into the PBS matrix was expected to enhance the rigidity and improve the crystalline and thermal behavior of the blends. Particularly, the high content of LS in the blends (the maximum content reached was 50 wt %) could sharply reduce the cost of PBS-based plastics and expand its application in many fields.…”