Cardanol Research Articles

Dynamic covalently bio-based polyurethane-boron nitride nanosheet composites for effective self-healing and thermal management

Polymer-based composites, such as polyurethane-based composites, provide better corrosion and fatigue resistance than other materials, but their poor thermal conductivity limits their application areas. In this study, using boron nitride nanosheets (BNNSs), cardanol (CA), and 2-hydroxyethyl disulfide (HEDS) as raw materials, we have developed an innovative dynamically covalently crosslinked bio-based polyurethane thermal management composite filled with BNNSs, which takes into account the sustainability of the bio-based polyurethane and the excellent thermal conductivity of BNNSs. We further explored the effect of different BNNSs content ratios on the material properties, and we found that the thermal conductivity could improve by 156 % at 10 wt% BNNSs-doping. Meanwhile, the dynamic covalent cross-linking strategy endows the material with self-healing ability after physical damage. Incorporating disulfide bonds allows the samples to be dynamically reversible at certain temperatures to repair material damage and remodel for recycling. The development of this material offers a new approach to enhancing the performance of bio-based polymer materials. It provides a new avenue for designing and applying eco-friendly materials with high thermal conductivity.

Amphiphilic Janus cotton gauze with enhanced moisture management and blood coagulation for rapid hemostasis and wound healing

Cotton gauze is commonly used in initial emergency care. However, its high hydrophilicity and limited clotting capacity can lead to the excessive absorption of blood, resulting in unnecessary blood loss. Herein, an amphiphilic Janus cotton gauze with excellent moisture management and enhanced blood coagulation has been developed via in situ generating bioactive glass (BG) onto the cotton gauze (CG), and then attaching cardanol (CA) onto one side of the BG-loaded CG (CG@BG) via click reaction. The Janus gauze (CA-CG@BG) has asymmetric wetting properties with a hydrophilic side (CA-CG@BGHL) and a hydrophobic side (HBCA-CG@BG). When applied to hemostatic, the porous and active BG on CA-CG@BGHL can rapidly initiate coagulation cascade to form a robust thrombus. CA on HBCA-CG@BG can entangled with each other, creating a hydrophobic barrier that prevents blood from flowing out. The hemostatic performance of CA-CG@BG is superior to that of CG in both rats and pigs. Interestingly, CA-CG@BG possesses unidirectional exudate removal. When applied to wound healing, the exudate can penetrate the hydrophobic HBCA-CG@BG to the hydrophilic CA-CG@BGHL, resulting in faster wound healing than CG. CA-CG@BG exhibits excellent cytocompatibility and hemocompatibility. This unique Janus dressing shows promise as a potential material for clinical applications in the future.

Improving the properties of polylactic acid/polypropylene carbonate blends through cardanol-induced compatibility enhancement

Cardanol (CD) is used as a reactive compatibilizer, and blended with polylactic acid (PLA) and polypropylene carbonate (PPC) resin (70/30(w/w)) to obtain a series of PLA/PPC/CD blends. The systematic study was conducted on the thermal properties, optical properties, rheological properties, mechanical properties, and microscopic morphology of the blend, by varying amounts of CD added to the blends. A detailed explanation and comprehensive analysis of the reaction mechanism between CD and PLA/PPC have been made. The study found that CD acts as a “bridge” between the PLA and PPC, forming the structure of a block copolymer (PLA-b-CD-b-PPC), and the copolymer can greatly improve the compatibility of PLA and PPC. When the amount of CD reaches 8 wt%, only one Tg is observed in the blend, simultaneously, PLA/PPC has already transitioned from a partially compatible system to a completely compatible system. At the same time, the addition of CD does not have any negative impact on the thermal stability of the PLA/PPC blend under processing temperature conditions, and the thermal stability of the PLA/PPC/CD blends can even be improved under extreme conditions. In addition, the addition of CD allows the PLA/PPC/CD blends to maintain a high light transmittance while reducing the opacity of the blend (the light transmittance remains above 92 %, and the opacity is reduced from 37 % to about 24 %), demonstrating excellent optical properties. Moreover, the elongation at break and impact strength of the PLA/PPC/CD blend both show a trend of first increasing and then decreasing with the increase of CD amount. When the CD amount varies within the range of 6– 8 wt%, the blends undergoes a brittle-ductile transition, and its toughness is greatly improved while the rigidity can also meet practical needs. When the amount of CD in the system increases to 12 wt%, the toughness of the blend reaches its peak, and its elongation at break and impact strength reach 513.24 % and 9211.5 J/m2 respectively (increased to 2442.84 % and 270.73 % of the PLA/PPC blend). Concurrently, the fracture surface of the blend exhibits large-scale plastic flow in the direction of the applied force, with marked shear yield phenomena, showing obvious characteristics of tough fracture.

Advances in Nanomaterials Based on Cashew Nut Shell Liquid.

Cashew nut shell liquid (CNSL), obtained as a byproduct of the cashew industry, represents an important natural source of phenolic compounds, with important environmental benefits due to the large availability and low cost of the unique renewable starting material, that can be used as an alternative to synthetic substances in many industrial applications. The peculiarity of the functional groups of CNSL components, such as phenolic hydroxyl, the aromatic ring, acid functionality, and unsaturation(s) in the C15 alkyl side chain, permitted the design of interesting nanostructures. Cardanol (CA), anacardic acid (AA), and cardol (CD), opportunely isolated from CNSL, served as building blocks for generating an amazing class of nanomaterials with chemical, physical, and morphological properties that can be tuned in view of their applications, particularly focused on their bioactive properties.

Anisotropic dispersion promoting and passivation protecting of CA@JNs@Zn2+ Janus nanosheets on epoxy anticorrosive coatings

Defects in the curing process of epoxy coatings tend to deteriorate the anticorrosion performance of the coatings. An important way to enhance the anticorrosion performance of epoxy coatings is to add flaky fillers. In this paper, anisotropic Janus nanosheets (JNs) were prepared and modified by cardanol (CA) and Zn2+. Then, the obtained CA@JNs@Zn2+ Janus composite nanosheets were introduced into epoxy coatings. When the content of CA@JNs@Zn2+ is 0.2 %, the mechanical properties and corrosion resistance of the coating were effectively improved. The tensile strength of 0.2 %-CA@JNs@Zn2+/EP coating is 79 % higher than that of pure epoxy coating. The EIS analysis showed that the low-frequency impedance of the coating remained as high as 16.45 Gohm·cm2 after 35 days of immersion, and remained above 10 Gohm·cm2 during the whole immersion period, which demonstrating the optimal corrosion resistance. This paper provides a theoretical basis for the preliminary application of Janus material in the field of anticorrosion, and the prepared composite coatings are expected to be used for anticorrosion in harsh environment.

Natural cardanol modified liquid polyisoprene rubber and its surface adhesion performance

Inspired by mussel protein, the adhesives based on dopamine boom due to its perfect adhesion performance. However, limited by its high price, it is of great significance to study adhesives originated from natural and renewable phenolic and polyphenol compounds which structure is similar to dopamine. The application of natural products can also reduce the consumption of non-renewable petrochemical resources. Herein, the agriculture and forestry by-products cardanol (CA) was grafted onto liquid polyisoprene rubber (LIR) molecular chains to improve its surface energy. Then, the grafting product (LCA) experienced complex formulation (GLCA) and vulcanization (v-LCA). The vulcanization crosslinking was confirmed by the weakening of double bonds absorption in IR spectra and C-C peak in XPS spectra, the enhancement of methyl proton in the α-position of quaternary carbon atom in 1H NMR spectra. The GLCA adhesive agent showed good adhesion performance on wet polar substrates because the drainage effect of LIR and the alkyl chains of CA. Moreover, CA provides the possibility of the multiple interactions as metal bonding, hydrogen bonding, cation-π interaction, π-π stacking, hydrophobic interaction and entanglement between chains. The v-LCA adhesive layer exhibits good solvent resistance. This study provides a prospect of the natural phenolic compounds from agriculture and forestry by-products to be used in the wet adhesion of industry, agriculture, or daily life.

Cardanol derivatives as compatibilizers for strengthening and toughening polylactic acid/bamboo fiber bio‐composites

AbstractThe application of bamboo fibers (BFs) as a reinforcing filler in polylactic acid (PLA) is hindered by their poor compatibility owing to the intrinsic hydrophilia of BFs and the hydrophobicity of PLA. To solve this issue, cardanol (CD) and epoxidized cardanol glycidyl ether (ECGE) were used as compatibilizers to strengthen and toughen PLA/BF bio‐composites, to the best of our knowledge, preparing PLA/BF/CD and PLA/BF/ECGE bio‐composites. The impact strengths of the synthesized bio‐composites increased from 7.75 to 23.75 and 7.75 to 23.95 kJ/m2, respectively, compared with that of a PLA/BF composite without compatibilizer. The investigation of the mechanical properties, crystallization, fractured surface morphology, and solvent stress‐cracking resistance properties revealed that the toughening mechanism of the PLA/BF/CD bio‐composites are mainly based on the plasticization of CD, which results in high impact toughness but low tensile strength. Moreover, the modification with ECGE improves the impact and tensile strengths of the bio‐composite owing to the following factors: (1) the epoxy groups of ECGE generate strong interactions with the BF surface and PLA to form an enhanced interfacial structure; (2) when present at high concentrations, chain extension reaction between ECGE and PLA to increase the molecular chain entanglement of PLA; and (3) upon curing and crosslinking, ECGE forms an entangled network structure that toughens the matrix.

Antileishmania and immunomodulatory potential of cashew nut shell liquid and cardanol

Conventional treatments for leishmaniasis have caused serious adverse effects, poor tolerance, development of resistant strains. Natural products have been investigated as potential therapeutic alternatives. The cashew nut shell liquid (CNSL) is a natural source of phenolic compounds with several biological activities, where cardanol (CN) is considered one of the most important and promising compounds. This study aimed to evaluate antileishmanial, cytotoxic and immunomodulatory activities of CNSL and CN. Both showed antileishmanial potential, with IC50 for CNSL and CN against Leishmania infantum: 148.12 and 56.74 μg/mL; against Leishmania braziliensis: 85.71 and 64.28 μg/mL; against Leishmania major: 153.56 and 122.31 μg/mL, respectively. The mean cytotoxic concentrations (CC50) of CNSL and CN were 37.51 and 31.44 μg/mL, respectively. CNSL and CN significantly reduced the percentage of infected macrophages, with a selectivity index (SI) >20 for CN. CNSL and cardanol caused an increase in phagocytic capacity and lysosomal volume. Survival rates of Zophobas morio larvae at doses of 3; 30 and 300 mg/kg were: 85%, 75% and 60% in contact with CNSL and 85%, 60% and 40% in contact with CN, respectively. There was a significant difference between the survival curves of larvae when treated with CN, demonstrating a significant acute toxicity for this substance. Additional investigations are needed to evaluate these substances in the in vivo experimental infection model.

Design and Synthesis of Epoxidized Soybean Oil‐Branched Cardanol Ethers as Poly(vinyl chloride) Plasticizers

AbstractTo overcome the migration of epoxidized soybean oil (ESO) used as a poly(vinyl chloride) (PVC) plasticizer, ESO‐branched cardanol (CD) ethers (ESO‐CDn) are designed and synthesized in this work. The incorporation of the benzene ring and the C15 straight chain of CD provided excellent plasticizing efficiency, and the increase in the molecular weight by branching CD with ESO enhanced the migration resistance of the plasticizer. In this work, two different methods are adopted to prepare PVC/ESO/CD and PVC/ESO‐CDn, namely the one‐step method (dynamic vulcanization of ESO, CD, and PVC) and the two‐step method (synthesis of ESO‐CD and then mixing it with PVC). The first method is convenient, while it is also uncontrollable, leading to an incomplete reaction between ESO and CD. The second method offers a controllable reaction between ESO and CD. The chemical structure of ESO‐CDn is fully characterized. Furthermore, the thermal, mechanical, rheology, and migration resistance properties of PVC/ESO/CD and PVC/ESO‐CDn are compared. The relationship between the molecular structure and plasticizer performance is investigated, and the plasticization mechanism is proposed. The tensile and thermal properties indicate that PVC/35ESO‐CD10 offered a superior anti‐thermal aging performance due to the excellent plasticizing and migration resistance effects of ESO‐CD10.

Synthesis and property study of novel maleimide‐cardanol based modifiers for epoxy resins

AbstractThe biomass‐based chemicals from renewable resources are countermeasures to ease the problem of fossil fuel shortage. This work is to develop a biobased functional reactive modifier for thermosetting epoxy resins appropriate for excellent overall performance. The novel maleimide‐cardanol modifiers (CA‐HPM) is synthesized from natural extract cardanol (CA) and N‐(4‐hydroxyphenyl) maleimide (HPM), which is then mixed with phenolic epoxy resin and linear phenolic novolac resin systems. CA‐HPM plays a versatile role in tuning the comprehensive properties of epoxy such as thermal property, adhesive property, and thermo‐mechanical property. Systems with CA‐HPM show slightly lower curing activity and distinct decreased single glass transition temperature (Tg). Besides, the crosslinking density of the cured resin increases, meanwhile the thermal stability keeps at high level, which is due to the rigid five‐membered ring structure of maleimide. Metal lap shear test results manifest that the adhesion between epoxy resin and metal interface augments. With 10% CA‐1HPM, the cured resin exhibits lower equilibrium water sorption (1.88%) and diffusion coefficient (2.94 × 10−8 s−1 cm2). This biobased functional reactive modifier has provided balanced overall performance and would pave the way to a wide range of possible “eco‐friendly” applications.

Environmentally Friendly Method of Assembly of Cardanol and Cholesterol into Nanostructures Using a Continuous Flow Microfluidic Device

This study shows a viable and straightforward microfluidic method of assembly of cardanol (CA) and cholesterol (CH) into amphiphile nanostructures obtained through a hydrodynamic focusing approach according to which an alcoholic solution of CA and CH is constrained within a two-dimensional lamina shape by two lateral streams of borate buffer solution. The process is performed within glass-made cross-shaped micro-sized fluidic chips specially designed to achieve a laminar regime. CA, distilled from the cashew nut shell liquid, is demonstrated as a surface-active molecule in borate buffer basic medium and when mixed with CH it produces versatile nanovesicles through an in-batch solvent-free process. Compared to this conventional method, the microfluidic route allows operating under continuous flows, with a reduced amount of reagents and at lower experimental temperatures, ensuring no waste formation and the achievement of size-monodisperse amphiphile nanostructures that do not need further steps of purification. Electron microscopy analyses demonstrate that upon increasing CH in the lipid mixture, a switchover from spherical CA micelles to CA/CH mixed closed vesicles occurs. Differential scanning microcalorimetry confirms the formation of vesicular structures and evidences the primary role of CH, which increasingly lowers the temperature of transition depending on its concentration.

Sheet-like Janus hemostatic dressings with synergistic effects of cardanol hemostasis and quaternary ammonium salt antibacterial action.

It is of utmost importance that bleeding should be stopped and infection be prevented in people with trauma. In this study, an anisotropic Janus mesoporous silica nanosheet (MSNS) with different functional groups was designed and prepared. In order to endow both sides of the MSNS with independent fast hemostasis and effective antibacterial action, the MSNS was modified with cardanol (CA) and 2,3-epoxypropyltrimethylammonium (GTA). The addition of CA significantly improved the hemostatic property of the MSNS. In a SD rat femoral artery injury model, the hemostatic time of CA-MSNS-GTA was 47% shorter than that of the MSNS, attributed to the sealing of the hydrophobic alkyl side chain and the adhesion of phenolic hydroxyl groups in CA. CA-MSNS-GTA could form a three-dimensional network with fibrin to further accelerate the coagulation process. This Janus material exhibited excellent antibacterial effects (∼90%) against Gram-positive bacteria (S. pneumoniae) and Gram-negative bacteria (E. coli) due to the presence of GTA. The cytotoxicity test showed that CA-MSNS-GTA exhibited biosafety, which provided safety guarantee for clinical applications in the future. This Janus dressing with different functions on two opposite sides provides synergetic multifunctional effects during wound healing.

Enhancement of cardanol-loaded halloysite for the thermo-oxidative stability and crystallization property of polylactic acid

A natural antioxidant, cardanol (CA), was loaded on halloysite nanotube (HNT) to fabricate a dual-functional green additive cardanol-loaded halloysite (HNT-CA) for the preparation of fully green polylactic acid (PLA) composites with improved thermo-oxidative stability and crystallization property. Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and transmission electron microscopy (TEM) measurements confirmed that cardanol was loaded in the lumen and attached on the outer surface of halloysite with approximately 22.9 wt% loading efficiency. The anti-aging behavior of HNT-CA was evaluated by the change of oxidation onset temperature (OOT) and weight-average molecular weight (Mw) of PLA composites stabilized by this additive after a 12-day aging test at 120 °C. The results showed that the OOT values of PLA composites with CA dropped from 298.2 °C to 279.0 °C, whereas the PLA composites with HNT-CA decreased from 292.2 °C to 281.5 °C, showing a higher retention. Similarly, the PLA stabilized by HNT-CA presented a higher retention of Mw than that stabilized by CA after thermal oxidation aging. For the PLA composites with HNT-CA, the migration of cardanol in PLA was inhibited by the restriction of halloysite to cardanol, thus showing long-term thermo-oxidative stability. Moreover, the analyses of polarized optical microscope (POM) and differential scanning calorimetry analysis (DSC) showed that HNT-CA increased the crystallization rate of PLA compared to HNT further due to the improved dispersion in PLA. These results indicated that HNT-CA exhibited excellent performance in improving the thermo-oxidative stability and crystallization property of PLA.

Improvement of β‐cyclodextrin/cardanol inclusion complex for the thermal‐oxidative stability and environmental‐response antioxidation releasing property of polylactic acid

AbstractIn this article, a β‐cyclodextrin(CD)/cardanol (CA) inclusion complex (IC) was fabricated by co‐precipitation method, which was used to guarantee excellent thermal oxidative stability and environmental‐response antioxidation releasing property of PLA. The results showed that CA was successfully immobilized into β‐CD with a stoichiometric ratio of 1:1, and the immobilization inhibited the migrant of CA from PLA during storage, resulting in the enhancement of antioxidant life of CA in PLA. Thus, PLA stabilized by IC (PLA/IC) maintained higher oxidation onset temperature (OOT) and molecular weight after long‐term thermal oxidative aging. Moreover, CA releasing comparison from PLA/IC and PLA stabilized by CA (PLA/CA) in food stimulant suggested that PLA/IC released CA faster than PLA/CA when PLA contacted with food stimulants due to the solubilization of β‐CD for CA, which would induce the quicker antioxidation of CA in food. In a word, IC can make PLA with longer anti‐oxidative stability during storage and quicker environmental‐response antioxidation releasing property during usage, showing strong potential as an active food‐packaging materials.

Wood Adhesives Based on Natural Resources: A Critical Review: Part IV. Special Topics

Various naturally-based chemicals can be used directly as wood adhesives or are precursors for the synthesis of adhesive resins. Liquefaction and pyrolysis of wood yield various smaller chemicals derived from the different wood components, which then are used in the preparation of adhesives by replacing mainly phenol as raw material. The possible replacement of formaldehyde in aminoplastic and phenolic resins would solve the question of the subsequent formaldehyde emission.<br/> The multiple unsaturations of the triglycerides in vegetable oils enable polymerization for the direct synthesis of thermosets, as well as bases for polyfunctionalization and crosslinking.<br/> Natural polymers, such as poly(lactic acid)s (PLAs), natural rubber, or poly(hyhydroxyalkanoate)s (PHAs) are thermoplastics and can be used for various special applications in wood bonding, in case they can also be crosslinked. For other thermoplastic wood adhesives, such as PUR or PA, chemicals based on natural resources can at least replace a part or even all synthetic raw materials (monomers); these monomers derive from targeted decomposition of the wood material in biorefineries.<br/> Cellulose nanofibrils (CNFs) can be used as as sole adhesives or as components of adhesives. Hydrogen bonding has a key function in binder applications related to adhesion between cellulose nanoparticles and other materials. CNFs are able to establish strong bonding between wood particles/fibres through flexible and strong films by a simple drying process.<br/> Cashew nut shell liquid (CNSL) is a by-product of the cashew nut processing with cardanol (CD) as main component. CD-formaldehyde resins show improved flexibility compared to phenol-formaldehyde (PF) resins; CD can replace up to 40% of the phenol.

Cardanol/SiO2 Nanocomposites for Inhibition of Formation Damage by Asphaltene Precipitation/Deposition in Light Crude Oil Reservoirs. Part I: Novel Nanocomposite Design Based on SiO2–Cardanol Interactions

This study aims to design a novel green nanocomposite based on the synergistic effect between silica nanoparticles (SN) and cardanol (CDN). The latter is an environmentally friendly dispersant comp...

Mesoporous silica MCM-41-reinforced cardanol-based benzoxazine nanocomposites for low-k applications

The two different benzoxazine (Bz) monomers were synthesized from two different bisphenol-AF (BF)- and bisphenol-S (BS)-based diamines with cardanol (CL) precursor, whose molecular structures were confirmed using spectroscopy tools. Further, 2.5 wt%, 5 wt% and 7.5 wt% of phenol-3-aminopropyltriethoxysilane benzoxazine-functionalized MCM-41 (APMS) were reinforced with cardanol-bisphenol AF core diamine-based benzoxazine (BFCL-Bz) and cardanol-bisphenol-S core diamine-based benzoxazine (BSCL-Bz) and cured, which leads to increased thermal stability. Successfully developed polybenzoxazines (PBz) nanocomposites dielectric properties were studied. It was observed that the incorporation of 7.5 wt% of APMS into BFCL-PBz polybenzoxazine results an ultra-low dielectric constant value of about 1.78 at 1 MHz, whereas the APMS/BSCL-PBz composites showed 2.16 for the same weight % concentration of APMS. This may be attributed to the presence of fluorine moieties in APMS/BFCL-PBz system. Data resulted from different studies, and it is concluded that the hybrid composites developed in the present work can conveniently be used in the form of adhesives, sealants and encapsulants for low k interlayer dielectric materials for high-performance microelectronics applications.

Improvement of Corrosion Resistance and Solid Content of Zinc Phosphate Pigmented Alkyd Coating by Methacrylated Cardanol

Two cardanol (CO) derivatives, methacrylated cardanol (MACO) and triethoxysilane functionalized cardanol (TSCO) were investigated as the reactive diluents for a zinc phosphate pigmented alkyd coating. It was found that 5 wt% of MACO or TSCO can reduce the dosage of xylene by ∼ 3 wt% while maintaining the viscosity of the alkyd coating system. TSCO presented a negative influence on the drying time and the pull-off adhesion strength of the alkyd coating; however, the addition of 15 wt% MACO decreased the drying time from 12 h to 8 h and increased the pull-off adhesion strength from ∼ 1.73 to ∼ 2.10 MPa, comparing with the neat alkyd coating (without MACO and TSCO). As evidenced by the salt spray test, the addition of TSCO did not show an enhancement of corrosion resistance for the alkyd coating; however, the alkyd coating containing 15 wt% MACO (labelled as M-15) presented superior corrosion resistance to other coating systems. M-15 and the neat alkyd coating were further characterized by electrochemical impedance spectroscopy (EIS). The results of EIS further demonstrated that the corrosion resistance of M-15 is much better than the neat alkyd coating in the 3.5 wt% NaCl solution immersion. Importantly, M-15 can provide an excellent protection of the steel in the corrosive immersion condition for at least 123 days. The improvement of the overall performance was attributed to the homo-polymerization of the methacrylate moiety in MACO. Taken these results together, MACO is an efficient chemical for formulating high solid alkyd coatings with outstanding corrosion resistance.

Influence of collagen cross-linkers addition in phosphoric acid on dentin biomodification and bonding of an etch-and-rinse adhesive

ObjectiveTo investigate the effects of natural collagen cross-linkers incorporation in phosphoric acid etchant on dentin biomodification, microtensile bond strength (μTBS) and nanoleakage (NL) of a two-step etch-and-rinse adhesive. MethodsExperimental aqueous solution of 37% ortho-phosphoric acid were prepared with the addition of 2% biomodification agents: Lignin (LIG) from industrial paper production residue, Cardanol (CARD) from cashew-nut shell liquid, and Proanthocyanidin (PAC) from grape-seed extract. Negative control (NC) was acid solution without cross-linker whilst commercial control (CC) was Condac 37 gel (FGM). Dentin specimens were assayed by FTIR after 15s etching to detect collagen cross-linking. Extracted third molars were used for μTBS (n=7) and fracture mode analysis of Optibond S (Kerr), tested after 24h or 1000 thermal cycles. NL was surveyed by SEM. Statistical analysis was performed with two-way ANOVA and Tukey’s test (p<0.05). ResultsFTIR confirmed cross-linking for all agents. μTBS of CC was the highest (46.6±6.2MPa), but reduced significantly after aging (35.7±5.2MPa) (p<0.001). LIG (30.6±3.7MPa) and CARD (28.3±1.8MPa) attained similar μTBS which were stable after aging (p>0.05). Fracture mode was predominantly adhesive. At 24h, all groups showed presence of silver uptake in hybrid layer, except CARD. After aging, CARD- and LIG-treated specimens exhibited little amount of silver penetration. CC, PAC and NC showed gaps, great nanoleakage at hybrid layer and presence of water channels in adhesive layer. SignificanceAltogether, ortho-phosphoric acid incorporated with LIG and CARD promotes stable resin-dentin bond strength with minor nanoleakage after aging, thereby achieving therapeutic impact without additional clinical steps.

가교 결합이 가능한 카다놀 기반 바이오 폴리올을 이용한 바이오 폴리우레탄 필름의 제조 및 특성

최근 식물성 오일은 생분해성, 재생 가능성 및 합리적인 가격이라는 특성을 바탕으로 바이오 물질 기반 폴리올의 제조에 많이 이용되고 있다. 이중 캐슈넛 껍질액(CNSL)에서 추출한 카다놀은 반응성 지방족 이중결합 및 다양한 중합체를 위한 새로운 기능성 물질을 제조할 수 있는 페놀 화합물을 포함하는 재생 가능한 자원이다. 수년에 걸쳐 카다놀의 다양한 유도체가 지속적으로 연구되었으며 또한 카다놀 기반의 폴리올은 폴리우레탄의 다양한 응용분야에서 연구되고 있다. 본 연구에서는 1,4-dibromobutane(DB)을 이용하여 카다놀을 브롬 말단 카다놀로 개질하였고, diethanolamine(DEA)을 이용하여 카다놀 유래 바이오 폴리올을 합성하였다. 카다놀 기반 폴리올의 분자구조는 1H NMR, FTIR 및 GPC로 분석하였다. 합성한 바이오 폴리올을 적용한 바이오 폴리우레탄 필름은 hexamethylene diisocyanate(HDI), dibutyltin dilaurate(DBTDL)를 촉매로 사용하여 제조하였다. 바이오 폴리우레탄 필름은 Escherichia coli(E. coli) 에 대하여 항균성을 보였으며, 긴 알킬 사슬의 이중결합을 곁사슬로 포함하기 때문에 가교도를 조절하여 물성조절이 가능했다. 가교 결합된 바이오 폴리우레탄 필름은 바이오 폴리우레탄 필름에 비해 높은 인장강도 및 열적 안정성을 보여준다. 이 연구의 결과는 카다놀 기반의 바이오 폴리우레탄이 환경친화적이고 다양한 응용분야에 적합한 후보물질이라는 것을 보여준다.