Multifunctional Polyurethane Research Articles

Multifunctional polyurethane coatings derived from phosphated cardanol and undecylenic acid based polyols

Renewable resource based polyol derived from undecylenic acid, a by-product of castor oil, was successfully synthesized by three consecutive reactions: methylation, thiol-ene addition, and amidation. The biobased polyol is a sulfur- and nitrogen-containing polyol. The structure was confirmed by FTIR, NMR, and mass spectroscopic techniques. The undecylenic acid based polyol was used as a polyol along with phosphated cardanol-based polyol in the preparation of polyurethane coatings. The obtained polyurethanes were assessed for their properties by various techniques such as thermogravimetric analysis (TGA), dynamic mechanical and thermal analysis (DMTA), Universal testing machine (UTM) and electrochemical study. Interestingly, the biobased polyol improved mechanical property such as toughness of the material when it was incorporated in different weight percentages to the phosphated cardanol-based polyol. Moreover, the synergistic effect of the phosphorous and biobased polyol with the elements - sulfur and nitrogen, enhanced the anti-corrosion and antimicrobial natures of the polyurethane coating. The corrosion rate was drastically decreased from 3.0 × 10–4 to 1.8 × 10–7 mm per year for the prepared polyurethane coatings.

Electromagnetic interference shielding behavior of chemically and thermally reduced graphene based multifunctional polyurethane nanocomposites: A comparative study

ABSTRACTThis article presents the effect of exfoliation, dispersion, and electrical conductivity of graphene sheets onto the electrical, electromagnetic interference (EMI) shielding, and gas barrier properties of thermoplastic polyurethane (TPU) based nanocomposite films. The chemically reduced graphene (CRG) and thermally reduced/annealed graphene (TRG) having Brunauer–Emmett–Teller surface areas of 18.2 and 159.6 m2/g, respectively, when solution blended with TPU matrix using N,N‐dimethylformamide as a solvent. Graphene sheets based TPU nanocomposites have been evaluated and compared for EMI shielding in Ku band, electrical conductivity, and gas barrier property. TRG/TPU nanocomposite films showed excellent gas barrier against N2 gas as compared to CRG/TPU. The EMI shielding effectiveness for neat CRG and TRG graphene sheets is found to be −80, −45 dB, respectively, at 2 mm thickness. The EMI shielding data revealed that TRG/TPU nanocomposites showed better shielding at lower concentration (10 wt %), while CRG displayed better attenuation at higher concentrations. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47666.

Multifunctional polyurethanes synthesized from different triarylamine units with electrochromic, photogeneration, memory storage and sensing properties

Herein, we report three multifunctional polyurethane materials, which exhibit excellent electrochromic, photoelectric, memory and sensing properties, and also have good mechanical properties.

Correction: Multifunctional polyurethanes synthesized from different triarylamine units with electrochromic, photogeneration, memory storage and sensing properties

Correction for ‘Multifunctional polyurethanes synthesized from different triarylamine units with electrochromic, photogeneration, memory storage and sensing properties’ by Xu Zhang et al., New J. Chem., 2019, 43, 1177–1185.

Synthesis of biobased polyols using algae oil for multifunctional polyurethane coatings

Renewable sources – namely, algae oil and diacids – were used for the synthesis of alkyd (ALK) and polyesteramide (PEA) polyols. The prepared polyols were characterised by Fourier transform infrared and nuclear magnetic resonance techniques and size exclusion chromatography analysis. After reaction with diisocyanate, polyols were converted to polyurethane (PU) coatings, which were then characterised by X-ray diffraction, differential scanning calorimetry and thermogravimetric analysis. The biocidal activities of the films were evaluated against Gram-negative (Escherichia coli ) and Gram-positive bacteria (Staphylococcus aureus) by using the turbidity method as well as by observation of film degradation or biofilm formation by bacteria on the surface of a metal tray by using scanning electron microscopy. The PUs obtained using ALK and PEA showed better antimicrobial properties compared with PUs based on algae oil fatty amide (AOFA), monoglyceride (MG) and even an uncoated mild steel (MS) panel. The anticorrosion properties of PU coatings were evaluated by the potential dynamic polarisation (PDP) method in a 3·5 wt% sodium chloride (NaCl) corrosive media. All coated samples (ALK and PEA) showed good barrier properties against corrosion compared with AOFA, MG and the uncoated MS panel. The prepared algae-oil-based PU coatings showed better chemical, mechanical, water-repellent, antimicrobial, anticorrosive and thermal properties.

Development of multifunctional polyurethane elastomer composites containing fullerene: Mechanical, damping, thermal, and flammability behaviors

Thermoplastic polyurethane (TPU) composites filled with fullerene in the range from 0.5 wt% to 2 wt% were fabricated using melt-compounding. Fullerene addition levels up to nearly twofold increase in tensile strength, percent elongation, and modulus of TPU. The mechanical properties are improved as modified C60 content decreases. Fullerene loadings also enhance thermal stability of TPU. Glass transition temperature decreases by the inclusion of C60 into TPU matrix. Composites exhibited the improvement for storage modulus and vibration-damping behavior. The UL-94 rating and limiting oxygen index value of TPU are also extended to higher values after C60 loadings. Adjuvant effect is observed on fire performance in which pristine C60 inclusions and higher concentrations of C60 exhibit better fire performance. Additions of C60 give identical melt flow index values with that of TPU. Modified C60 particles disperse more homogeneously than pristine ones into TPU matrix because of the improvement in interfacial interactions between fullerene and polyurethane elastomer.

Heparin-mimetic polyurethane hydrogels with anticoagulant, tunable mechanical property and controllable drug releasing behavior

In the present study, novel heparin-mimetic polyurethane hydrogels were prepared by introducing chemical crosslinked sulfated konjac glucomannan (SKGM). Scanning electron microscopy (SEM) results indicated that the introduction of SKGM and the increase of the molecular weight of diol segments could enlarge the pore sizes of the hydrogels. The swelling behavior corresponded with the SEM results, and the hydrogels could absorb more water after the modification. The modification also led to an improvement in the mechanical property. Meanwhile, the SKGM and the modified polyurethane hydrogels showed excellent hemocompatibility. The thromboplastin time of SKGM could reach up to 182.9s. Gentamycin sulfate (GS) was used as a model drug to be loaded into the hydrogels, and the loading amount was increased ca. 50% after the introduction of SKGM, thus resulting in high bactericidal efficiency. The results indicated that the introduction of SKGM and the alternation in the diol’s molecular weight bestowed polyurethane hydrogels with promising properties of integrated blood-compatibility, mechanical properties and drug loading-releasing behavior. Therefore, the heparin-mimetic multifunctional polyurethane hydrogels have great potential to be used in biomedical applications.

Smart multifunctional polyurethane microcapsules for the quick release of anticancer drugs in BGC 823 and HeLa tumor cells.

Smart multifunctional drug delivery systems (DDSs) based on cytophilic fluorescent polyurethane copolymer microcapsules with high tumor cell internalization, triggered release, quick cancer cell death and real time fluorescent monitoring abilities is developed as a facile and versatile approach for precision cancer therapy.

Multifunctional cationic polyurethanes designed for non-viral cancer gene therapy

Nano-polyplexes from bioreducible cationic polymers have a massive promise for cancer gene therapy. However, the feasibility of cationic polyurethanes for non-viral gene therapy is so far not well studied. In this work, a linear cationic polyurethane containing disulfide bonds, urethane linkages and protonable tertiary amino groups was successfully generated by stepwise polycondensation reaction between 2,2′-dithiodiethanol bis(p-nitrophenyl carbonate) and 1,4-bis(3-aminopropyl)piperazine (BAP). We confirmed that the cationic polyurethane (denoted as PUBAP) displayed superior gene delivery properties to its cationic polyamide analogue, thus causing higher in vitro transfection efficiency in MCF-7 and SKOV-3 cells. Besides, further folate-PEGylation and hydrophobic deoxycholic acid (DCA) conjugation to amino-containing PUBAP can be conducted to afford multifunctional polyurethane gene delivery system. After optimization, folate-decorated nano-polyplexes from the PUBAP conjugated with 8 folate-PEG chains and 12 DCA residues exhibited superb colloidal stability under physiological conditions, and performed rapid uptake via folate receptor-mediated endocytosis, efficient intracellular gene release and nucleus translocation into SKOV-3 cells in vitro and in vivo. Importantly, PUBAP based polyplexes possess low cytotoxicity as a result of PUBAP biodegradability. Therefore, marked growth inhibition of SKOV-3 tumor xenografted in Balb/c nude mice was achieved with negligible side effects on the mouse health after intravenous administration of PUBAP based polyplexes with a therapeutic plasmid encoding for TNF-related apoptosis-inducing ligand. This work provides a new insight into biomedical application of bio-responsive polyurethanes for cancer therapy. Statement of significanceIn this study, we have confirmed that disulfide-based cationic polyurethane presents a new non-viral vector for gene transfer and cancer gene therapy. The significance of this work includes: (1) design and synthesis of a group of novel disulfide-based cationic polyurethane by non-isocyanate chemistry; (2) comparative study of transfection activity between cationic polyurethanes and cationic polyamides; (3) feasibility of bioreducible cationic polyurethanes for in vivo cancer gene therapy.

A route toward multifunctional polyurethanes using triple click reactions

The aliphatic polyurethane with pendant alkyne, perfluorophenyl, and anthracene moieties (PU-anthracene) was prepared from polycondensation of anthracene, alkyne, and perfluorophenyl functional-diols with hexamethylenediisocyanate in the presence of dibutyltindilaurate (DBTL) in CH2Cl2 at room temperature for 10 days. Thereafter, the PU-(anthracene-co-alkyne-co-perfluorophenyl) (Mn,GPC = 15,400 g/mol, Mw/Mn= 1.37, relative to PS standards) was sequentially clicked with benzyl azide, octylamine, and 4-(2-hydroxyethyl)−10-oxa-4-azatricyclo[5.2.1.02,6]dec-8-ene-3,5-dione (adduct alcohol) via copper-catalyzed azide-alkyne cycloaddition, active ester substitution and Diels–Alder reactions, respectively, to finally yield PU-(hydroxyl-co-benzyltriazole-co-octylamine). The PUs were characterized using 1H NMR, GPC, and DSC. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 480–486

Multifunctional polyurethane–urea nanoparticles to target and arrest inflamed vascular environment: A potential tool for cancer therapy and diagnosis

Activation of inflammatory pathways in endothelial cells contributes to tumour growth and progression in multiple human cancers. Cellular adhesion molecules are involved in leukocyte recruitment to the vascular inflammatory environment where it plays a critical role in angiogenesis, suppression of apoptosis, proliferation, invasion and metastasis. We describe here the development of streptavidin-coated polyurethane–urea nanoparticles as multifunctional nanocarriers for fluorescence imaging or targeting of the tumour environment to identify and arrest the vascular network irrigating the tumour tissue. The design of these multifunctional nanoparticles involves incorporating streptavidin to the nanoparticle polymeric matrix. The obtained nanoparticles are spherical and exhibit an average diameter of 70–74nm. Streptavidin-coated nanoparticles spontaneously bind biotinylated antibodies against VCAM-1 and ICAM-1 which in vitro and in vivo specifically attached to inflamed endothelial cells. Indeed the incorporation of CBO-P11 (a specific inhibitor of the vascular endothelial growth factor proangiogenic and proinflammatory pathway) to these nanoparticles allows a targeted pharmacological effect thereby decreasing the proliferation only in inflamed endothelial cells. The multiple functionalisation strategy described here could be exploited for tumour diagnostics or targeted drug delivery to tumour vasculature with a good safety profile and an attractive array of possibilities for biomedical applications.

Hydroxyl‐functional polyurethanes and polyesters: synthesis, properties and potential biomedical application

AbstractThis mini review gives an overview of the synthesis of polyurethanes and polyesters with pendant hydroxyl groups performed mainly in our group. Significant for the synthesis of most of these polymers with hydroxyl‐functional side groups is that no protection groups are needed. This is realised either by generating the OH group during polymer synthesis—demonstrated by the preparation of hydroxyl‐functional polyurethanes from dicarbonate monomers and diamines—or by using catalysts which discriminate between primary and secondary OH groups—demonstrated by the synthesis of hydroxyl‐functional polyesters based on malic acid using scandium triflate as catalyst. In addition, the potential of carbonate couplers for the synthesis of multifunctional polyurethane is presented. The application of such multifunctional polyurethanes as antimicrobial polymers and coatings is briefly discussed. Copyright © 2012 Society of Chemical Industry

Investigation on Properties of a New CB/WPUA Composite Coating

By grafting carbon black (CB) with multifunctional waterborne polyurethane acrylate (WPUA), a series of environmental-friendly CB/WPUA black coatings with different CB contents were prepared in this study. The chemical structures of the products at different synthesis stages were analyzed by Fourier-transform infrared spectroscopy (FT-IR), and the influence of carbon black content on the properties of coatings was systemically investigated. The experimental results demonstrated that the WPUA/CB composite coatings with more CB contents had higher viscosities and impaired unsaturation conversions of WPUA. However, the coating containing 4 wt% of CB obtained the best water resistance and tensile strength owing to incorporate organic-inorganic structures, which is of importance for practical application.

Synthesis and Characterization of pH-Sensitive Biodegradable Polyurethane for Potential Drug Delivery Applications

To obtain a pH-sensitive multifunctional polyurethane micelle drug carrier, a novel pH-sensitive macrodiol containing acid-cleavable hydrazone linkers, poly(e-caprolactone)−hydrazone−poly(ethylene glycol)−hydrazone−poly(e-caprolactone) diol (PCL−Hyd−PEG−Hyd−PCL), was synthesized and characterized with proton nuclear magnetic resonance spectra (1H NMR). A series of pH-sensitive biodegradable polyurethanes (pHPUs) were designed and synthesized using pH-sensitive macrodiol, l-lysine ethyl ester diisocyanate (LDI) and l-lysine derivative tripeptide as chain extender, which can provide an active reaction site for the development of positive target polyurethane micelles for drug delivery. The bulk structures of the prepared polyurethanes were carefully characterized with 1H NMR, gel permeation chromatograph (GPC), differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FT-IR). The polyurethanes could be cleaved in acidic media (pH ∼ 4−6) as well as degraded in PBS and enzymatic solu...

Synthesis and properties of novel polyurethane acrylate containing 3-(2-hydroxyethyl) isocyanurate segment

Novel UV curable multi-functional polyurethane acrylate (PUA) containing 3-(2-hydroxyethyl) isocyanurate (THEIC) segment was synthesized through three step reactions, the ring-opened reaction of ɛ-caprolactone with THEIC under the catalysis of tetrabutyl titanate (TBT), the polyaddition reaction between formed hydroxyl compounds and isophorone diisocyanate (IPDI) and condensation reaction between the product of the second step and pentaerythritol triacrylate (PETA). The chemical structure of PUA oligomer and some influence factors in synthesis process were characterized with GPC, 1H NMR and FTIR. And its photopolymerization process and properties of cured films were also investigated.

Telechelic Multifunctional Polyurethane-Based Macroinitiator for the Synthesis of Polystyrene-block-Polyurethane-block-Polystyrene Tri-Block Copolymers via Atom Transfer Radical Polymerization

Atom transfer radical polymerization was successfully used to synthesize polystyrene-b-polyurethane-b-polystyrene tri-block copolymers (PSt-b-PU-b-PSt) using telechelic multifunctional polyurethane (Br3C-PU-CBr3) as a macroinitiator. Along with macroinitiator, CuBr and N,N,N′,N″,N″-pentamethyldiethyltetramine (PMDETA) were also used as catalyst and ligand, respectively to polymerize styrene. The linear increase of with conversion shows that Br3C-PU-CBr3/CuBr/PMDETA initiating system polymerizes styrene through controlled radical polymerization mechanism. Mole ratio of polyurethane and polystyrene present in PSt-b-PU-b-PSt tri-block copolymers was calculated using proton nuclear magnetic resonance spectroscopy and the results were found to be comparable with the gel permeation chromatography results. Differential scanning calorimetric results confirmed the presence of polyurethane and polystyrene phases in the tri-block copolymers.

Structure and Properties of Tough Thermoplastic Starch Modified with Polyurethane Microparticles

Aged thermoplastic starch (TPS), plasticized with hydrophilic plasticizers such as glycerol, shows brittle property. It is critical to develop tough TPS without using hydrophilic plasticizers. In this work, polyurethane prepolymer (PUP) was synthesized and mixed reactively with TPS in an intensive mixer to prepare modified TPS. Structural and morphological analyses showed that polyurethane (PU) microparticles were formed in situ and dynamically cross-linked to the starch matrix through urethane linkages. The modified TPS without hydrophilic plasticizer become tough. The elastic polyol soft segments in PU played the role of impact modifier, improving the toughness of the modified TPS. Almost 100% of PU was cross-linked to starch, indicating high efficiency of the modification. Formation of multifunctional PU microparticles was essential to achieve the high reaction efficiency. The dynamically cross-linking modification is a novel, green, and efficient method for preparing tough TPS.

Multifunctional polyurethane network structures

AbstractA series of thirteen polyurethanes were synthesized using blends of monofunctional, difunctional, and trifunctional poly(propylene oxides) reacted with 4,4'‐diphenylmethane diisocyanate in a stoichiometric ratio. Experimental measurements were made of glass transition temperature, sol fraction, and dynamic mechanical properties. Computer simulations based on the theory of branching processes were made on the same systems. The glass transition temperature was correlated with the number average functionality of the components. Dynamic mechanical data was fitted to the Havriliak‐Negami model. A correlation was demonstrated between the measured rubbery modulus and the concentration of elastically active network chains.

New photorefractive polymer based on multifunctional polyurethane

A new photorefractive polymer containing a photocarrier generator, a hole transporting compound, and a nonlinear optical chromophore covalently linked to the polymer backbone has been synthesized. Two-beam coupling experiments have clearly demonstrated asymmetric energy exchange under zero-field condition, a sign for photorefractivity and a maximum optical gain of 0.88 cm−1 was measured. Although it is not a net gain, the result reported here demonstrates the feasibility of rational designs of photorefractive polymers.