Synthetic polymer-lignin copolymers and blends

Wang, Jiashu; Manley, R. St. John; Feldman, D.

doi:10.1016/0079-6700(92)90003-h

Cited by 88 publications

(63 citation statements)

References 70 publications

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“…1,2 Especially, industrial lignin derived from by-product of pulping and papering can be commercially available in low-cost. 3 Recently, high reactive lignin with a unique phenylpropane structure has been used to replace petroleum-resources, while environment protection also impulses the research of lignin-based materials due to its biodegradability and nontoxicity.…”

Section: Introductionmentioning

confidence: 99%

“…2,4 Traditionally, lignins have been evolved as polymeric materials via chemical reaction 4,5 or graft polymerization, 2,6,7 and incorporated into polymer matrices as filler. 2,[8][9][10][11][12] As the multilevel structures of lignin and its derivatives, such as chemical structure, 13 spherical conformation, 14 and supramolecular aggregate, 8,15 have been gradually identified, the understanding in the role of lignin in polymeric materials has made great progress. Usually, a three-dimensional network structure of lignin, 3 which is built on CÀ ÀC and CÀ ÀO linkages of phenylpropane units, is shown as a dense and rigid sphere, 16 and acts as core to derivate star-like 7 or hyperbranched structures.…”

Section: Introductionmentioning

confidence: 99%

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Simultaneous enhancement in strength and elongation of waterborne polyurethane and role of star‐like network with lignin core

Cui

Fan

Xia

et al. 2008

J of Applied Polymer Sci

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ABSTRACT:We have reported that a star-like network structure with lignin as center in polyurethane resulted in the simultaneous enhancement in mechanical strength and elongation. In this study, we aimed to enhance the mechanical properties of waterborne polyurethane by adding nitro-lignin (NL) to form analogical star-like network. It was found that the resultant material has optimal mechanical performances when the NL content is 3.0 wt %, i.e., its apparent mechanical strength and elongation increased by about 80% at one time. Especially, its real mechanical strength reaches 71.3 MPa at this time, which is 3.6-fold over that of neat waterborne polyurethane material. The simultaneous enhancements in strength and elongation are attributed to the forming of star-like network in the composites. The stiffness of lignin improved the mechanical strength, while the entangling and crosslinking in polyurethane component increased the elongation. However, higher NL loading and lower grafting level induced the forming of supramolecular NL aggregates, and hence greatly inhibited star-like network, resulting in lower mechanical strength and elongation. However, the Young's modulus of the material is enhanced with an increase of rigid supramolecular aggregates.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Simultaneous enhancement in strength and elongation of waterborne polyurethane and role of star‐like network with lignin core

Cui

Fan

Xia

et al. 2008

J of Applied Polymer Sci

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“…1,2 Especially, based on its renewable, non-toxic, and biodegradable character, lignin-based materials has been considered to deal with the petroleumresources crisis and environment pollution. Since lignin has all kinds of functional groups (hydroxyl, carboxyl, phenol, etc.…”

Section: Introductionmentioning

confidence: 99%

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

Cui

Xia

Chen

et al. 2007

J of Applied Polymer Sci

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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.

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“…These units contain both primary and secondary hydroxyl groups with properties similar to those of polyols. Lignin samples contain different types and quantities of these functional groups that could beu t i l i z e di nm a k i n ga n d / o r replacing a majority of petroleum-based products in the manufacture of industrial biomaterials and biocomposites 6,7 such as polyurethanes. 8,9 Lignin incorporation in polyurethane production has been one of the most intensively investigated applications.…”

Section: ' Introductionmentioning

confidence: 99%

Preparation of Lignopolyols from Wheat Straw Soda Lignin

Ahvazi

Wojciechowicz

Ton-That

et al. 2011

J. Agric. Food Chem.

113

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Wheat straw soda lignin was modified and characterized by several qualitative and quantitative methods such as 31 P NMR spectroscopy to evaluate its potential as a substitute for polyols in view of polyurethane applications. Chemical modification of the lignin was achieved with propylene oxide to form lignopolyol derivatives. This was performed by a two-step reaction of lignin with maleic anhydride followed by propylene oxide and by direct oxyalkylation under acidic and alkaline conditions. The physical and chemical properties of lignopolyols from each method and the subsequent chain-extended hydroxyl groups were evaluated. Direct oxyalkylation of lignin under alkaline conditions was found to be more efficient than acidic conditions and more effective than the two-step process for preparing lignopolyol with higher aliphatic hydroxyl contents.

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Synthetic polymer-lignin copolymers and blends

Cited by 88 publications

References 70 publications

Simultaneous enhancement in strength and elongation of waterborne polyurethane and role of star‐like network with lignin core

Simultaneous enhancement in strength and elongation of waterborne polyurethane and role of star‐like network with lignin core

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

Preparation of Lignopolyols from Wheat Straw Soda Lignin

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