Waterborne Polyurethane Composites Research Articles

Influence of the Dispersion of Carbon Nanotubes on the Electrical Conductivity, Adhesion Strength, and Corrosion Resistance of Waterborne Polyurethane Composites

Due to the presence of many flammable substances in the working environments of the petrochemical industry, anticorrosive conductive coatings need to be used on metal equipment to avoid safety accidents like fires. However, existing conductive solvent-based coatings are volatile when exposed to flammable and toxic organic solvents. Thus, in this work, a series of eco-friendly anticorrosive waterborne polyurethane (WPU) composites with multi-walled carbon nanotubes (MWCNTs) were prepared via a low-cost and practical process; the dispersion of MWCNTs was revealed when present in different amounts, and the mechanism behind the conduction of WPU composites was determined. We concluded that low amounts of MWCNTs were well dispersed, generating a conductive network, and the WPU composite was not entirely covered by the MWCNT particles, so the electrical conductivity in certain parts of the coating was good. When the content of MWCNTs was excessive, some stretched MWCNTs dispersed to the top of the composite and many MWCNTs agglomerated at the bottom. Additionally, when the content of MWCNTs was increased, the electrical conductivity, corrosion resistance, and adhesion strength of the WPU composite decreased. Our results could provide a theoretical foundation for the preparation of anticorrosive conductive waterborne composites for protecting equipment in the petrochemical industry.

Innovative Microbial Immobilization Strategy for Di-n-Butyl Phthalate Biodegradation Using Biochar-Calcium Alginate-Waterborne Polyurethane Composites.

Di-n-butyl phthalate (DBP) is a prevalent phthalate ester widely used as a plasticizer, leading to its widespread presence in various environmental matrices. This study presents an innovative microbial immobilization strategy utilizing biochar, calcium alginate (alginate-Ca, (C12H14CaO12)n), and waterborne polyurethane (WPU) composites to enhance the biodegradation efficiency of DBP. The results revealed that rice husk biochar, pyrolyzed at 300 °C, exhibits relatively safer and more stable physical and chemical properties, making it an effective immobilization matrix. Additionally, the optimal cultural conditions for Bacillus aquimaris in DBP biodegradation were identified as incubation at 30 °C and pH 7, with the supplementation of 0.15 g of yeast extract, 0.0625 g of glucose, and 1 CMC of Triton X-100. Algal biotoxicity results indicated a significant decrease in biotoxicity, as evidenced by an increase in chlorophyll a content in Chlorella vulgaris following DBP removal from the culture medium. Finally, microbial community analysis demonstrated that encapsulating B. aquimaris within alginate-Ca and WPU layers not only enhanced DBP degradation, but also prevented ecological competition from indigenous microorganisms. This novel approach showcases the potential of agricultural waste utilization and microbial immobilization techniques for the remediation of DBP-contaminated environments.

Sustainable waterborne polyurethane/lignin nanoparticles composites: Durability meets degradability

Optimizing the durability and degradability of polymers is essential for prolonging their useful life and minimizing their environmental footprint post-use, contributing to a sustainable world; however, durability in many cases conflicts with degradability. In this context, we developed lignin-based waterborne polyurethane (WPU) composites that bypass this dichotomy. Lignin nanoparticles (LNP), derived from enzymatic hydrolysis lignin (EHL), were synthesized using the anti-solvent method and incorporated into WPU emulsions through solution blending. The introduction of 5 wt% LNP notably improved the tensile strength of WPU composites, increasing it from 21.5 MPa to 29.7 MPa, a surge of up to 38 %. Moreover, 5 wt% of LNP significantly enhanced the durability of WPU by reducing creep strain (under a stress of 1 MPa for 3000 s) from 606 % to 70 % with an 88 % decrease, and by increasing molecular weight retention rate from 11 % to 87 % after 15 days of UV exposure. Concurrently, LNP notably accelerated the alkaline degradability of WPU/LNP composites, with weight loss rate increasing from 38 % to 92 % (a 142 % increase) and molecular weight loss from 17 % to 44 % (a 159 % increase), compared to pure WPU. The strategy employed in this study leverages the inherent properties of LNP to offer a promising approach to enhancing polymer sustainability, presenting an effective solution to the significant end-of-life challenge.

Multistage microcellular waterborne polyurethane composite with optionally low-reflection behavior for ultra-efficient electromagnetic interference shielding

Electromagnetic interference (EMI) shielding materials with superior shielding efficiency and low-reflection properties hold promising potential for utilization across electronic components, precision instruments, and fifth-generation communication equipment. In this study, multistage microcellular waterborne polyurethane (WPU) composites were constructed via gradient induction, layer-by-layer casting, and supercritical carbon dioxide foaming. The gradient-structured WPU/iron-cobalt loaded reduced graphene oxide (FeCo@rGO) foam serves as an impedance-matched absorption layer, while the highly conductive WPU/silver loaded glass microspheres (Ag@GM) layer is employed as a reflection layer. Thanks to the incorporation of an asymmetric structure, as well as the introduction of gradient and porous configurations, the composite foam demonstrates excellent conductivity, outstanding EMI SE (74.9 dB), and minimal reflection characteristics (35.28 %) in 8.2–12.4 GHz, implying that more than 99.99999 % of electromagnetic (EM) waves were blocked and only 35.28 % were reflected to the external environment. Interestingly, the reflectivity of the composite foam is reduced to 0.41 % at 10.88 GHz due to the resonance for incident and reflected EM waves. Beyond that, the composite foam is characterized by low density (0.47 g/cm3) and great stability of EMI shielding properties. This work offers a viable approach for crafting lightweight, highly shielding, and minimally reflective EMI shielding composites.

Preparation and properties of water‐borne polyurethane‐sodium lignosulfonate/nano‐calcium carbonate composites

AbstractTo improve the application range of waterborne polyurethane (WPU), in this study, nano calcium carbonate/sodium lignosulfonate (CaCO3/SL) composites were prepared using sodium lignosulfonate (SL) wet‐modified calcium carbonate nanoparticles. Then, a series of waterborne polyurethane (WPU) nanocomposites (WPU‐CaCO3/SL) were prepared by solution mixing. Zeta, FT‐IR, XRD, SEM, and TGA were used to characterize the structure and morphology of CaCO3/SL and WPU‐CaCO3/SL. By conducting an analysis on the impact of various dosages of CaCO3/SL composite on the performance of WPU, the findings revealed that the tensile strength of WPU‐CaCO3/SL nanocomposites, when composed with a 3 wt% CaCO3/SL dosage, exhibited a significant increase of 116% from 6.93 to 14.95 mPa. The water contact angle demonstrated a significant increase from 78.3° to 90.1°. Additionally, the maximum decomposition temperature showed a noticeable rise of approximately 7°C. The WPU exhibit enhanced heat resistance, water resistance and mechanical properties, as well as exceptional ultraviolet (UV) absorption capabilities. This study provides a reference for modifying polymers with inorganic fillers and improving the optical properties of polymeric materials.Highlights Successful modification of nano calcium carbonate using biopolymer SL. Modified CaCO3/SL can be uniformly dispersed in water. Improved thermal stability of WPU composites. WPU composites exhibit excellent mechanical properties and water resistance. Well‐dispersed CaCO3/SL improves ultraviolet radiation resistance of WPU composites.

Carbon fiber in situ grown ZIF‐67 nanocrystals with excellent electrochemical and interfacial property

AbstractCarbon fiber(CF) reinforced flexible composites had a wide range of applications. However, the interfacial adhesion of composites was weak as a result of the smooth and chemically inert CF surface. To settle this issue, this paper described a method to enhance the specific surface area, roughness and wettability of the CF surface by in situ growing Cobalt‐based zeolitic imidazolate framework (ZIF‐67) nanocrystals and CF reinforced waterborne polyurethane (WPU) composites were prepared by a simple casting method. Scanning electron microscopy clearly revealed uniformly grown ZIF‐67 nanoarrays with distinct morphology on the CF surface. As a result, the CF@ZIF‐3 electrode exhibited excellent electrochemical property, with specific capacitance reaching 368.2 mF/cm2. The reinforcing effect of ZIF‐67 with different morphology was further verified through transverse fiber bundle tension test and shear bonding strength measurements, showing improvements of 51.9 and 72.1% respectively, in comparison to the CF/WPU composites due to the unique structure of the ZIF‐67 nanocrystals acted as buffer area, effectively relieving stress concentration and altering the direction of crack propagation. As a result, the interfacial properties of the composites were enhanced. Moreover, tensile and tear strengths of CF@ZIF/WPU composites showed remarkable improvement compared to CF/WPU composites. This study presented a potential reinforcement strategy for achieving high‐performance CF/WPU composites.Highlights ZIF‐67 with different morphologies were grown in situ on the CF surface. CF@ZIF electrode exhibited excellent electrochemical property. ZIF‐67 interface layer improved interfacial properties of composites. The tensile strength of the composites improved after ZIF‐67 modification. Introduction of ZIF‐67 enhanced the tear strength of composites.

Dual network interpenetrating degradable waterborne polyurethanes with hydrogen bonded cross‐linked modified β‐cyclodextrin hydrophobic cavities

AbstractThe study gives an investigation on the properties of β‐cyclodextrin (β‐CD) waterborne polyurethane (WPU) composites with cross‐linked network structure and hydrogen bonding system. The polyurethane films modified with β‐CD/PEG exhibit superior thermal stability and biodegradability, it is capable to be applied to bio‐degradable plastic coatings. To improve the distribution of β‐CD in WPU, the β‐CD was modified by three different molecular weights of polyethylene glycol hydrophile (PEG). Since the chain segments and hydrophilic hydroxyl groups of PEG interact with the hydrophobic cavities and edges of β‐CD to form new complexes, thus enhancing the flexibility and structural integrity of WPU chains and conferring better biological properties. The analysis focuses on the changes of thermal stability and biodegradability after modification. The results indicated that the temperature of maximum thermal weight loss rate (Tmax) of β‐CD/PEG/WPU composites reached 394.1°C and the soft segment glass transition temperature (Tg) was −42.4°C after the introduction of β‐CD/PEG. Both are significantly improved compared to WPU, with degradation rates of 31.2% in lipase PBS solution and 14.8% in soil, and can therefore be better applied to current medical devices and biodegradable coatings, as well as other bio‐environmental areas.

Improved Anticorrosion Properties of Polyurethane Nanocomposites by Ti3C2Tx MXene/Functionalized Carbon Nanotubes for Corrosion Protection Coatings

The corrosion protection of MXene-based composite coatings is challenging due to the relatively low dispersion of MXene in organic coatings. In this work, waterborne polyurethane (WPU) composites containing hybrid nanoadditives of Ti3C2Tx MXene and functionalized carbon nanotubes (CNTs) were fabricated. The thermal stability, surface hydrophobicity, surface roughness, and mechanical properties of the nanocomposites containing MXene or MXene/CNT hybrid additives were studied. Electrochemical methods, including electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization scans, were utilized to evaluate the anticorrosion properties of the nanocomposite coatings when applied to copper substrates. The polyurethane sample with 0.95 wt % Ti3C2Tx MXene and 0.05 wt % CNTs showed the lowest corrosion rate of 2.1 × 10–3 μm year–1. Additionally, the EIS results revealed that the corrosion resistance of WPU/MXene coatings significantly increased by adding 0.05 wt % CNTs. The mechanism of the improved anticorrosion performance of the WPU/MXene/CNT composite coating is illustrated. Moreover, the importance of optimizing the concentration of the CNTs is discussed to obtain better corrosion protection. The polyurethane nanocomposite coatings reported in this work present great potential as corrosion protection coatings for metals and other surfaces.

EMI shielding, thermal and antibacterial performances of ecofriendly castor oil–based waterborne polyurethane favored by combining carbon nanotube and cetyltrimethylammonium bromide

Many ecofriendly and antibacterial polymer-based shielding nanocomposites have been designed to address the increasingly serious issues of electromagnetic interference (EMI) pollution and antibiotic resistance. These composites contain high amounts of conductive and antibacterial material and exhibit an unsurpassed EMI shielding performance and strong antibacterial properties. However, it is extremely challenging to prepare these materials because of the formation of large aggregates coupled with the high viscosity. Herein, carbon nanotubes (CNTs) and an antibacterial surfactant (cetyltrimethylammonium bromide (CTAB)) are mixed with castor oil–based waterborne polyurethane (WPU) via ultrasonic-assisted solution mixing followed by a freeze-drying approach. Owing to the presence of CTAB, CNTs (at a concentration of 24.3 wt%) are evenly dispersed and connected to each other in the WPU matrix. This morphology and intrinsic characteristics of CNTs enable the resultant CNT/WPU composites to exhibit an excellent electrical conductivity (635.8 S/m) and thermal conductivity (0.308 W/(m·K)) as well as an incomparable shielding effectiveness (SE, 88.81 dB). Notably, the specific SE reaches 997.4 dB/cm, which exceeds those of the reported composites. Moreover, the combination of CNTs and CTAB improves the antibacterial activities of the WPU composites. Due to these merits, the resultant composites have great potential for applications in portable and wearable smart electronics. Overall, this study opens a new way toward the manufacture of ecofriendly and multifunctional polymer composites.

Improving fire safety and mechanical properties of waterborne polyurethane by montmorillonite-passivated black phosphorus

A novel phospho-silicon co-flame retardant material composed of montmorillonite modified black phosphorus nanosheets (MMT-BP) is synthesized using a liquid phase intercalation method. MMT-BP nanosheets are utilized to improve the thermal stability, mechanical properties, and fire safety of waterborne polyurethane (WPU). After passivation, MMT-BP nanosheets exhibit high stability during degradation even when immersed in 25 °C water for three months. Compared to pure WPU, the tensile strength of the 0.4-MMT-BP/WPU composite is increased by 59.6%, and the elongation at break is maintained. The limiting oxygen index of the 0.4-MMT-BP/WPU composite is increased from 21.7% to 27.2%. Furthermore, the peak heat release rate, total heat release, and the peak value of smoke production rate of 0.4-MMT-BP/WPU are significantly reduced by 33.43%, 13.85% and 32.40%, respectively. The superior flame-retardancy observed in the WPU nanocomposites containing 0.4 wt% MMT-BP is attributed to the formation of an Si-O-P bond between BP and MMT during passivation and the enhanced catalytic carbonization of BP in the condensed phase. In this paper, an effective passivating method of black phosphorus is proposed and a highly efficient flame retardant based on black phosphorus is obtained.

Cellulose nanocrystals-based bio-composite optical materials for reversible colorimetric responsive films and coatings

Photonic materials with a tunable chiral nematic structure that can selectively reflect light dynamically are valuable for applications in smart responsive materials. Here, we prepared potential photonic composites with a chiral nematic structure by forming cellulose nanocrystals (CNCs) and waterborne polyurethane (WPU) composites with different compositions on different substrates by evaporation-induced self-assembly. With increasing WPU content, the reflected wavelength increased from 400 to 680 nm, which was mainly caused by the increase of the chiral nematic pitch. In addition, the mechanical properties were better for higher WPU content. WPU was sensitive to small amounts of moisture in ethanol owing to the swollen WPU after absorbing water will increase the helical pitch. The reversible red shift induced by moisture was approximately 100 nm. When wood was used as the substrate, the CNCs still self-assembled to form chiral nematic structures and the adhesion forces of the composites to the wood substrate were strong. By using MgCl2 solution as an ink, invisible patterns can be written on the coating, which can be revealed temporarily by ethanol. In addition, the invisible pattern of photonic coating is rewritable. The easily prepared environmentally friendly photonic composite has great potential in sensors, anti-counterfeiting labels and smart decorative coatings.

The preparation and study of functionalized graphene oxide/self-healing waterborne polyurethane composites

The preparation and study of functionalized graphene oxide/self-healing waterborne polyurethane composites

Waterborne polyurethane composites flame retardancy based on the bi-DOPO derivatives and dangling poly(dimethylsiloxane) chains

The composites phosphorus-silicon flame retardant was simultaneously employed to modify waterborne polyurethane (WPU). The WPU films modified with the composites flame retardant were characterized in detail. The composites flame retardancy, residual carbon morphology, and graphitization of the films were evaluated by cone calorimetry, scanning electron microscopy (SEM), and Raman spectroscopy, respectively. The results showed that the weight loss temperature of the WPU film was 402.45 °C when the weight loss rate was as high as 90 % in the N2 atmosphere, and the PHRR and THR values of the flame-retardant films were as low as 222.3 kW/m2 and 22.9 MJ/m2, respectively. Compared with the neat WPU, the LOI of the film decorated with the composites flame retardant was increased by 39.13 %. The high graphitization degree of the residue char was formed to improve strength and shield properties of the modified WPU film. The flame-retardant mechanism was attributed to the active phosphorus-containing free-radical quenching effect and diluting effect of nonflammable gases in the gas phase, and owing to the catalysis effect the formation of phosphorus/silicon-rich char residue layers in the condensed phase.

Flexible spiral-like multilayer composite with Fe3O4@rGO/waterborne polyurethane-Ni@polyimide for enhancing electromagnetic shielding

A well-designed multilayer composite with a unique spiral structure consisting of polyimide (PI) fabric and waterborne polyurethane (WPU) created by hot compression molding method for lightweight and flexible electromagnetic interference (EMI) shielding materials. Electroless Ni plating was employed to prepare the Ni@PI fabric and Fe3O4@rGO was evenly distributed throughout the WPU to provide conductivity and magnetism. Based on the reduced graphene oxide/WPU (rGO/WPU) composites, the addition of Fe3O4 nanoparticles improves the EMI shielding effectiveness (SE) of Fe3O4@rGO/WPU composites, especially the absorption efficiency. The continuous conductive network included in the Fe3O4@rGO/WPU-Ni@PI composite firmly locks electromagnetic wave as they enter the interior and provides more interfaces to increase multiple reflection losses, thus showing higher SE than traditional multilayer composites. The maximum SE value (36.8 dB) of the spiral structure composite with only 6.2 wt% Ni and 8.53 wt% Fe3O4@rGO loading is higher than that of conventional multilayer composites (27.0 dB), breaking through the bottleneck of high filler loading and low SE of conductive polymeric composites. Furthermore, after 1000 bending cycles, the composite with spiral structure retains significant EMI SE. The composite offers a wide range of applications, including electromagnetic protection for flexible electronic devices and the next generation of communication equipment.

Low-loading oxidized multi-walled carbon nanotube grafted waterborne polyurethane composites with ultrahigh mechanical properties improvement

The uniform dispersion of oxidized multi-wall carbon nanotubes (OCNT) in waterborne polyurethane (WPU) matrix was achieved by in-situ polymerization, endowing the OCNT/WPU composite film with enhanced tensile strength, thermal stability, and excellent elongation at break. The structure of multi-wall carbon nanotubes (CNT) and OCNT was characterized by TEM, XRD, XPS, and the structure and morphology of composites were characterized by particle size analysis, SEM and FT-IR. Compared with pure WPU and OCNT/WPU composite, the breaking strength and the thermal degradation temperatures of 20 % weight loss of the OCNT/WPU composite were increased by 175 % and 353 °C, respectively. The oxygen-containing functional groups effectively improved the surface active of OCNT, making it easier for OCNT to react with polyurethane prepolymers. After addition of only 1 % OCNT, the tensile strength approaches 77 MPa while the elongation at break remains at 277 %. In addition to having outstanding chemical and mechanical properties, OCNT have a better dispersibility rate than multiwalled carbon nanotubes, which means that they will have a broader application range. • By in situ polymerization, oxidized carbon nanotubes are grafted into polyurethane systems. • Oxidized carbon nanotubes offer better performance than pristine carbon nanotubes. • Adding 1 % oxidized carbon nanotubes to waterborne polyurethane improved mechanical properties by 175 %.

Rational Design for Efficiently Improving the Sensitivity of Ti3C2 MXene-Based Waterborne Polyurethane Composites toward High-Performance Wearable Electronics

Rational Design for Efficiently Improving the Sensitivity of Ti₃C₂ MXene-Based Waterborne Polyurethane Composites toward High-Performance Wearable Electronics

Bis(2-hydroxyethyl) terephthalate from depolymerized waste polyester modified graphene as a novel functional crosslinker for electrical and thermal conductive polyurethane composites

Bis(2-hydroxyethyl) terephthalate (BHET) with active hydroxyl group derived from waste polyester can be applied as a polyurethane chain extender and an organic modifier for graphene oxide (GO). Herein, functionalized reduced GO (BHET-rGO) with single-layer was obtained by modifying GO with BHET, and then reduced by hydrazine hydrate. Waterborne polyurethane (WPU) nanocomposites with excellent mechanical performance, electrical and thermal conductivities were prepared via in-situ polymerization using the novel functional crosslinker BHET-rGO. Compared with the same content of rGO (7.41 wt%), WPU/BHET-rGO composites exhibit better properties containing equivalent BHET content. For example, BHET-rGO endows the WPU composites with higher tensile strength of 39.1 MPa (enhanced by 454.6%), electrical conductivity of 8×10−3 S/m (improved by 15 times), and thermal conductivity of 0.551 W m−1 K−1 (increased by 21.1%). Meanwhile, the sensitivity of WPU/BHET-rGO composite is well recovered during a large-strain stretching/shrinking cycle, and its resistance is stable under complex deformation. Besides, significant thermal stability ensures the durable of polyurethane to resist high-temperature. Hence, BHET-rGO have greater potential for fabricating high-performance elastomer composites, especially for conductive elastomer composites.

Properties and Fabrication of Waterborne Polyurethane Superhydrophobic Conductive Composites with Coupling Agent-Modified Fillers.

The addition of abundant fillers to obtain conductive and superhydrophobic waterborne polyurethane (WPU) composites generally results in increased interfaces in the composites, leading to reduced adhesion and poor corrosion resistance. Fillers such as Polytetrafluoroethylene (PTFE) and multi-walled carbon nanotubes (MWCNTs) were first treated by a coupling agent to reduce the contents of the fillers. Thus, in this work, WPU superhydrophobic conductive composites were prepared using electrostatic spraying (EsS). The polar groups (-OH and -COOH, etc.) on the WPU, PTFE, and MWCNTs were reacted with the coupling agent, making the WPU, PTFE, and MWCNTs become crosslinked together. Thus, the uniformity of the coating was improved and its curing interfaces were reduced, causing enhanced corrosion resistance. The dehydration reaction that occurred between the silane coupling agent and the polar surface of Fe formed -NH2 groups, increasing the adhesion of the coating to the steel substrate and then solving the problems of low adhesion, easy delamination, and exfoliation. With the increased content of the modified fillers, the conductivity and hydrophobic property of the composite were amplified, and its corrosion resistance and adhesion were first strengthened and then declined. The composite with the WPU, PTFE, MWCNTs, and KH-550 at a mass ratio of 7:1.5:0.1:0.032 held excellent properties; its volume resistivity and WCA were 1.5 × 104 Ω·cm and 155°, respectively. Compared with the pure WPU coating, its adhesive and anticorrosive properties were both better. This provides a foundation for the fabrication and application of anticorrosive and conductive waterborne composites.

Electrochemical deposition assisted the construction of titanium carbide@polyaniline hybrid in waterborne polyurethane conductive network for improved electromagnetic interference shielding and flame retardancy

To solve the increasing serious electromagnetic radiation pollution and limitations of metal-based electromagnetic shielding materials in flexible devices, the polyaniline (PANI) is deposited on the surface of two-dimensional Ti3C2 to obtain the Ti3C2@PANI hybrid for constructing waterborne polyurethane (WPU) composite. Meanwhile, to address the flame risk of WPU composite, the two-dimensional black phosphorous (BP) is incorporated as a flame retardant to prepare isolated flame-retardant black phosphorous-waterborne polyurethane/Ti3C2@polyaniline(Q-FBP-WPU/Ti3C2@PANI) composite with isolated structure. Due to the existence of conductive fillers and the isolated structure, the Q-FBP-WPU/Ti3C2@PANI composite exhibited the highest electrical conductivity (2.23 S/m) and the electromagnetic shielding effectiveness (EMI SE) of 27.3 dB in the frequency range of 8.2–12.4 GHz (X-band) and retains higher than 20 dB after hundreds of stretching and bending, which completely satisfies the commercial demands. Compared with the composite with a disordered structure, the thermal conductivity of Q-FBP-WPU/Ti3C2@PANI is increased by 93.3%. The cone test results show that the peak heat release rate, total heat release, total smoke production and total CO production of Q-FBP-WPU/Ti3C2@PANI is decreased by 46.2%, 16.3%, 21.2% and 15.5% than that of pure WPU, certifying the fire safety of WPU are greatly improved. This work supports a novel and applicable idea for constructing functional electromagnetic shielding materials.

Composite waterborne polyurethane reinforced with silane modified lignin as an adhesive between polypropylene decorative films and wood‐based panels

AbstractTo improve the surface bonding strength of polypropylene (PP) decorative films on wood‐based panels, one kind of lignin, namely sodium lignosulfonate (SL) filled waterborne polyurethane (WPU) composites were used as adhesives on the back of the PP decorative films, and the SL was modified by the addition of two alternative types of silane that contain either ethylene‐acyloxy or epoxy groups. The PP decorative films were hot‐press onto plywood using the different types of SL modified WPU as an adhesive. The SL and SL modified WPU were characterized comprehensively. The surface properties the PP decorative films on plywood surfaces were tested. The results showed that both types of silane can be grafted on the SL between hydrolyzed SiOH groups and OH groups. The long organic chain of silane can physically twist to the WPU, where self‐polymerization of the silane helps to form network structures. As a result, the surface bonding strength of PP decorative films on plywood surfaces largely improved with SL filled WPU adhesives and no detachment occurred in boiling water. Compared with the ethylene‐acyloxy silane, the epoxy silane performed better which was associated with the reactions between the epoxy groups and free water.