Novolac Resin Research Articles

Structural effects on heat capacity, moisture absorption and thermal expansion of epoxy-novolac polymers

Today epoxy novolac resins are of great interest for the aerospace industry. Thermal properties of the polymer matrix, as well as the effect of moisture on the characteristics of polymer composite materials (PCM) under thermomechanical impacts, are critical tasks in creating dimensionally stable structures operating in a wide temperature range. Particularly, thermal and moisture expansion as well as heat capacity are important parameters for evaluating of polymer matrices and modeling their properties. In this work, polymers based on a number of epoxy novolac resins with aromatic amine hardener were studied. The values of the crosslink density were experimentally determined, and a comparative analysis of thermal expansion and heat capacity for epoxy polymers with different crosslink density was carried out. The dependence of thermophysical properties on polymer crosslinking density is shown, both in glass and highly elastic states. Additionally, this study analyzes the process of water sorption by polymers and the coefficient of moisture expansion. The most significant dependence of the diffusion coefficient was observed with coefficient of moisture expansion.

The influence of binder type on the properties and performance of taphole clays for blast furnaces

Taphole clay (THC) is an unshaped refractory commonly used in blast furnaces to seal the taphole after the tapping process has been completed. THC is typically bonded with conventional coal tar pitch (CTP), but alternative binders have been developed due to the high toxicity of this material. This study investigated the performance of various binders commonly added to THCs, including CTP, phenolic novolac resin (PNR), low benzopyrene coal tar pitch (ECTP), and a petroleum-based binder (PBB). The properties of the prepared THCs were investigated, and the analytical hierarchy process was used to infer the behaviour of the prepared materials during blast furnace operation. The results obtained show that the best binder for a particular THC depends on its operational requirements. In cases where excellent injectability and hearth protection are mandatory, CTP or ECTP are highly recommended. Conversely, if a low-toxicity and easy-to-drill THC is required, PBB emerges as a promising binder. PNR is the recommended choice for blast furnaces where rapid cure and tapping stability are priorities.

A latent curing agent for rapid curing of phenolic epoxy resin at low temperature

AbstractDeveloping effective latent curing agent for rapid curing of epoxy resins at low temperatures remains challenging. This study reports a latent curing agent, ortho‐cresol phenolic epoxy resin‐bisphenol A (EOCN‐BPA), prepared through the addition reaction of o‐methyl phenolic epoxy resin with BPA. When blended with dicyandiamide (DICY) in a 1:3 molar ratio, EOCN‐BPA/DICY is used to cure a linear epoxy phenolic novolac (EPN) resin (epoxy equivalent: 550 g eq−1, softening point: approximately 82°C), at an onset curing temperature of 90°C, which is considerably lower than the onset curing temperature of DICY with EPN (160°C). However, EOCN‐BPA does not react with EPN without a catalyst. Therefore, this latent curing system is successfully applied in powder coatings, rapid curing at 120°C within 3 min without an additional catalyst, outperforming the EPN/EOCN‐BPA system using cocatalyst 2‐methylimidazole. Consequently, DICY catalyzes the curing reaction between the phenol hydroxyl group and epoxy resin and participates in it. The prepared powder coating exhibits excellent storage stability, maintaining its properties for over 3 months at room temperature. These findings demonstrate the excellent latent properties of EOCN‐BPA/DICY, highlighting its potential as a highly effective latent curing agent.

Advanced, high‐performance thermo‐insulating plaster

AbstractThe main purpose of many current studies regarding energy efficiency is the improvement of the thermal resistance of buildings. To fulfill this goal, the development of advanced insulating materials, to be incorporated in the building envelopes, is imperative. Aerogels are ultralight porous materials typically produced via the sol‐gel process followed by supercritical drying of the wet gel. They exhibit very high porosities and a mesoporous‐macroporous structure which endows aerogels with extremely low thermal conductivity. This makes them ideal candidates for ambient thermal insulation applications. However, the cost for aerogel insulation is considerably higher than the one of standard insulation products. In the present work, highly porous aerogel‐like materials based on silica and commercial novolac resin were developed and added to common mortars. The prepared materials were dried under ambient pressure to minimize the manufacturing cost. The bulk density of silica quasi‐aerogels was 0.03 g/cm3–0.09 g/cm3 and that of the novolac resin samples 0.09 g/cm3–0.21 g/cm3. The aerogels were incorporated in mortars and cured for 28 days before measurement of thermal conductivity. The values of the thermal conductivity coefficient of the measured samples were 0.047 W/m K–0.058 W/m K for the silica reinforced mortars and 0.036 W/m K–0.044 W/m K for the novolac reinforced ones.

Performance enhancement of phenolic resin by glycol‐modified lignin

AbstractWithout using fossil resources such as petroleum and coal, which are likely to be depleted and have a large load on the environment, we studied the improvement of the performance of phenolic resin using lignin‐based natural material, which is a non‐fossil resource that is less likely to cause environmental problems. Using modified lignin with polyethylene glycol, the modified lignin phenolic novolac resin was synthesized, and the properties of the phenolic resin molding material and molded article containing the modified lignin were evaluated. As a result, it was found that the phenolic resin into which the modified lignin was introduced not only has excellent moldability, but also excellent heat resistance, mechanical strength, and electrical insulation, and can achieve both heat resistance and flexibility.

Performance of novolac resin‐ and resole resin‐based carbon/carbon composites in relation to their fabrication conditions

AbstractThe demands of cost‐driven industrial applications can be satisfied by manufacturing composites with a low volume fraction of carbon fibres as phenolic carbon fibre‐reinforced composites and C/C composites, both with acceptable performances, for low‐ or high‐temperature applications, respectively. Polymeric composites reinforced with a low volume fraction (7.5% v/v) of carbon fibres were fabricated using laboratory‐produced phenolic resins, novolac (N) and resole (R), as matrices after different curing/post‐curing temperature profiles. By optimising the manufacturing conditions, the N‐based polymeric composites exhibited higher flexural strength, whereas the R‐based composites showed higher shear strength. C/C composites, namely N‐based and R‐based, were manufactured by pyrolysis of the previously prepared polymeric composites up to 1000 °C. The pyrolysed composites were then densified by impregnation with an appropriate resin solution, followed by curing and new pyrolysis, and particularly by employing 1 up to 4 consecutive cycles of ‘impregnation–curing/pyrolysis’. Weight changes resulting from the impregnation–curing and pyrolysis stages were determined. The curing of both resins was verified by Fourier Transform Infrared Analysis. The apparent density and X‐ray diffraction data of the C/C composites were used to calculate their total percent porosities. The morphology and elemental composition of the C/C composites at their failure region (after flexural testing) were examined by Scanning Electron Microscopy/Energy‐Dispersive X‐ray Analyses. In comparison to the N‐based C/C composites, the R‐based ones exhibited: higher shear strength, lower flexural strength, higher Shore D hardness, slightly higher surface conductivity and lower volume conductivity. The optimum conditions for the manufacture of C/C composites were achieved by applying two consecutive cycles of ‘pyrolysis–impregnation–pyrolysis’ to the polymeric composites. © 2024 The Authors. Polymer International published by John Wiley & Sons Ltd on behalf of Society of Industrial Chemistry.

Preparation and properties of novolac epoxy resins containing polycyclic aromatic hydrocarbons

AbstractTo meet the demands of high‐density and miniaturized integrated circuits, electronic packaging materials need to have excellent properties. One approach to enhance the performance is to design novel structures. In this study, two novolac oligomers containing naphthalene Naphthalene novolac oligomer (NPF) and biphenyl Biphenyl novolac oligomer (LPF) were synthesized and then reacted with epichlorohydrin to synthesize novel novolac epoxy resins containing polycyclic aromatic hydrocarbons (NPF‐EP and LPF‐EP). Their chemical structures were characterized by Fourier transform infrared and 1H nuclear magnetic resonance spectra. Tetrahydromethyl‐1,3‐isobenzofurandione (MeTHPA) was used as curing agent to prepare cured NPF‐EP/MeTHPA and LPF‐EP/MeTHPA thermosets. Both NPF‐EP/MeTHPA and LPF‐EP/MeTHPA exhibited better thermal and mechanical properties compared with novolac epoxy resin (PF‐EP/MeTHPA). In particular, NPF‐EP/MeTHPA presented the highest glass transition temperature of 193°C and LPF‐EP/MeTHPA had excellent mechanical properties, with tensile and flexural strengths of 94 and 151 MPa, respectively. Additionally, the cured NPF‐EP/MeTHPA and LPF‐EP/MeTHPA also exhibit a lower dielectric constant and dielectric loss, and low coefficient of thermal expansion compared with cured PF‐EP/MeTHPA. This investigation provides valuable insights for the manufacturing of high‐performance novolac epoxy resins for application in electronic packaging materials.

Assessing thermal hazards in bio-oil-glyoxal polymerization and curing with DGEBA and bio-char

Traditional novolac resin uses formaldehyde and an excess of phenol under an acid catalyst which has a remarkable production and wide applications, however, the polymerization and its curing reaction are highly exothermic and heat generation with the release of harmful gases (formaldehyde and phenol) link to a high potential of thermal runaway hazard and the possibility of explosions in resin factories. To make a sustainable novolac-type resin, the water-insoluble fraction of bio-oil glyoxal (BOG) resin was utilized as an ideal phenol bioresource. The safety criteria of renewable resins polymerization and its curing reaction were investigated using the Differential Scanning Calorimeter (DSC) and evaluated by comparing the critical runaway conditions with those of traditional non-renewable resins. The reaction mechanism of the novolac resin synthesis and curing reaction were discussed as well. The results indicate that the use of bio-oil can reduce the heat risk of polymerization reactions. The introduction of biochar for the first time in curing reactions has shown a potential beyond anticipation in reducing the heat risk of curing reactions.

Epoxidized technical Kraft lignin as a particulate resin component for high-performance anticorrosive coatings

Deterioration of steel infrastructures is often caused by corrosive substances. In harsh conditions, the protection against corrosion is provided by high-performance coatings. The major challenge in this field is to find replacements for the fossil-based resins constituting anticorrosive coatings, due to increasing needs to synthesize new environmentally friendly materials. In this study, softwood Kraft lignin was epoxidized with the aim of obtaining a renewable resin for anticorrosive coatings. The reaction resulted in the formation of heterogeneous, solid, coarse agglomerates. Therefore, the synthetized lignin particles were mechanically ground and sieved to break up the agglomerates and obtain a fine powder. To reduce the use of fossil fuel-based epoxy novolac resins in commercial anticorrosive coatings, a series of formulations were prepared and cured on steel panels varying the content of epoxidized lignin resin. Epoxidized lignin-based coatings used in conjunction with conventional epoxy novolac resin demonstrated improved performance in terms of corrosion protection and adhesion properties, as measured by salt spray exposure and pull-off adhesion test, respectively. In addition, the importance of size fractionation for the homogeneity of the final coating formulations was highlighted. The findings from this study suggest a promising route to develop high-performing lignin-based anticorrosive coatings.

Controlling the Synthesis of Polyurea Microcapsules and the Encapsulation of Active Diisocyanate Compounds.

The encapsulation of active components is currently used as common methodology for the insertion of additional functions like self-healing properties on a polymeric matrix. Among the different approaches, polyurea microcapsules are used in different applications. The design of polyurea microcapsules (MCs) containing active diisocyanate compounds, namely isophorone diisocyanate (IPDI) or hexamethylene diisocyanate (HDI), is explored in the present work. The polyurea shell of MCs is formed through the interfacial polymerization of oil-in-water emulsions between the highly active methylene diphenyl diisocyanate (MDI) and diethylenetriamine (DETA), while the cores of MCs contain, apart from IPDI or HDI, a liquid Novolac resin. The hydroxyl functionalities of the resin were either unprotected (Novolac resin), partially protected (Benzyl Novolac resin) or fully protected (Acetyl Novolac resin). It has been found that the formation of MCs is controlled by the MDI/DETA ratio, while the shape and size of MCs depends on the homogenization rate applied for emulsification. The encapsulated active compound, as determined through the titration of isocyanate (NCO) groups, was found to decrease with the hydroxyl functionality content of the Novolac resin used, indicating a reaction between NCO and the hydroxyl groups. Through the thorough investigation of the organic phase, the rapid reaction (within a few minutes) of MDI with the unprotected Novolac resin was revealed, while a gradual decrease in the NCO groups (within two months) has been observed through the evolution of the Attenuated Total Reflectance-Fourier-Transform Infrared (ATR-FTIR) spectroscopy and titration, due to the reaction of these groups with the hydroxyl functionalities of unprotected and partially protected Novolac resin. Over longer times (above two months), the reaction of the remaining NCO groups with humidity was evidenced, especially when the fully protected Acetyl Novolac resin was used. HDI was found to be more susceptible to reactions, as compared with IPDI.

Programmable optical switching integrated chip for 4-bit binary true/inverse/complement code conversions based on fluorinated photopolymers.

In this work, programmable optical switching integrated chips for 4-bit binary true/inverse/complement optical code conversions (OCCs) are proposed based on fluorinated photopolymers. Fluorinated bis-phenol-A novolac resin (FAR) with low absorption loss and fluorinated polyacrylate (FPA) with high thermal stability are self-synthesized as core and cladding layer, respectively. The basic architecture of operating unit for the photonic chip designed is composed of directional coupler Mach-Zehnder interferometer (DC-MZI) thermo-optic (TO) switching, X-junction, and Y-bunching waveguide structures. The waveguide module by cascading 16 operating units could realize OCCs function through optical transmission matrix. The response time of the 4-bit binary OCCs is measured as about 300 µs. The insertion loss and extinction ratio of the actual chip are obtained as about 10.5 dB and 15.2 dB, respectively. The electric driving power consumption for OCCs is less than 6 mW. The true/inverse/complement OCCs are achieved by the programmable modulation circuit. The proposed technique is suitable for achieving optical digital computing system with high-speed signal processing and low power consumption.

Radiation-Induced Alteration of the Reflection Spectra of Diazoquinone–Novolac Photoresist Films by Implantation of Ag+ Ions

FP9120 diazoquinone–novolac positive photoresist films 1.5 μm thick implanted with Ag+ ions and supported on the surface of KDB-10 (111) silicon wafers by centrifugation have been studied by measuring reflection spectra. It has been shown that ion implantation leads to a decrease in the refractive index of the photoresist due to radiation crosslinking of novolac resin molecules and a decrease in the density ρ and the molecular refraction RM of the photoresist. It has been established that the reflection coefficient in the opaque region of the photoresistive film increases with the Ag+ implantation dose. The changes observed in the optical properties of the films under ion implantation conditions are explained taking into account radiation-chemical processes in the phenol–formaldehyde photoresist.

Synthesis, characterization, and properties of a novel propargyl ether naphthalene phenolic resin

AbstractIn this study, 1,5‐dihydroxynaphthalene moiety was introduced into a novolac resin structure, and propargyl ether naphthalene phenolic resin (PNPF) was synthesized by the Williamson etherification reaction, which improved the heat resistance of the resin and its processability. The structure of the PNPF resin was characterized using 1H NMR and FTIR analysis, and its processability, heat resistance, thermal expansion, and dielectric properties were evaluated. The results revealed that the addition of 1,5‐dihydroxylhine, increased the reaction activity of the PNPF resin, and decreased its initial curing temperature, with the resin exhibiting excellent processability. The cured resin also showed excellent heat resistance and thermomechanical properties. The 5% weight loss temperature (Td5) and glass transition temperature (Tg) of the resin increased to 437.61 and 362.04°C, respectively, while the coefficient of thermal expansion decreased from 60.17 to 44.52 ppm, with a reduction of 26.01%. Moreover, the dielectric constant and dielectric loss of the cured resin were 3.02 and 0.00239, respectively.

Techno-economic analysis of developing miscanthus biorefinery for the production of platform chemicals and renewable resins

Biorefining to produce chemical materials is a viable path to a renewable and sustainable future. The energy crop Miscanthus is grown with high yield and low cost. In this study, platform chemicals (acetic acid, glycolaldehyde, and acetol) and novolac resins were produced using Miscanthus at a baseline plant capacity of 15 t/h. The profitability of different biochar applications (soil amendment, heat supply, and activated carbon) was investigated by mass balance and energy consumption analysis and economic assessment. The heat supply scenario had the best profitability with an internal rate of return (IRR), payback period, levelized cost, and minimum selling price of 24.5%, 4.32 years, CNY 8,480/t, and CNY 10,840/t. Sensitivity analysis showed that IRR was most sensitive to resin price, plant capacity, and capital costs. The minimum plant capacity with an IRR over 25% was 25 t/h. Monte-Carlo simulation results showed a low investment risk for soil amendment and heat supply scenarios.

Introducing a new approach for designing advanced epoxy film adhesives with high mechanical, adhesion, and thermal properties by adding hybrid additives for structural bonding

BackgroundEpoxy-based adhesives are widely used in different industries in various forms. Among them, epoxy film adhesives are particularly applicable in constructing honeycomb structures in aerospace systems. However, these adhesives suffer from brittleness, low flexibility, and thermal stability. In the current paper, the effect of pure and functionalized SiO2 and ZrO2 nanoparticles (NPs), the addition of a block copolymer (butyl acrylate-block-styrene), and Novolac resin on the mechanical, thermal, and adhesive properties of the epoxy film adhesive were thoroughly studied. MethodsThe mechanical properties, thermal stability, and surface morphology of the epoxy adhesive samples were evaluated using tensile, thermogravimetric analysis (TGA), and field emission scanning electron microscopy (FE-SEM) images, respectively. More importantly, the Lap shear and Peel tests were utilized to investigate the adhesive properties. Significant findingsPure and functionalized NPs were added to the prepared epoxy adhesive samples. Intriguingly, compared to the non-functionalized NPs, by only adding 1 phr of each functionalized NPs to the formulation, the tensile modulus, tensile strength, and toughness increased to 66 %, 197 %, and 553 %, respectively. More importantly, the single lab shear and T-peel strength were increased as high as 121 % and 101 %, respectively, indicating a synergistic effect. After optimizing the parameters effective on the properties, FE-SEM images of the fractured surface of optimized samples were used to study the possible fracture mechanisms, including crack deflection, crack pinning, nanoparticle debonding, and shear band formation. Also, this synergistic effect was observed in the thermal stability where the only addition of 1 phr of functionalized NPs increased the decomposition onset temperature up to 40 ℃ higher than the neat one. This simple and applicable method can pave the way for using functionalized NPs in modifying epoxy adhesives.

The effect of novel advanced method on the properties of novolac hybrid nanocomposites reinforced with carbon nanotube and glass fiber

AbstractIn this study, the effects of ball milling (BM) technique and carbon nanotube (CNT) content on the thermal and mechanical properties of hybrid reinforced composites were investigated. The composites were prepared using glass fiber (GF), novolac resin (No), and CNTs with different wt% (1, 2, and, 4). Various milling times were used to optimize the entanglement/agglomeration of CNTs in the polymer matrix and subsequently enhance the final thermal and mechanical properties. Through precise investigations, it was found that the nanocomposite with 2 wt% CNT reinforcement, subjected to 2 h of BM, exhibited remarkable enhancements in key properties. The tensile strength was significantly improved to 45.6 MPa, while the elastic modulus reached 3.419 GPa. Hardness was measured at 96 HRM, and thermal conductivity was enhanced to 0.463 W/mK. Moreover, this sample demonstrated a weight loss that was 43.65% lower compared to the sample reinforced with 1 wt% CNT and subjected to 1 h of BM. Overall, this study highlights the importance of optimizing the milling time and CNT content in the preparation of polymer nanocomposites, and it provides valuable insights for the development of advanced materials with superior performance in various applications.

Red mud waste/nanoclay/polystyrene‐modified epoxy hybrid composites: Mechanical, thermal, and flammability properties

AbstractIn this study, bisphenol A‐type epoxy (ER) and epoxy phenol novolac resins (EPN) with two amine‐type curing agents (KH 816 and IPOX EH 2041) having different total amine values were selected. The mechanical properties and density of the EPN resin were found higher in the case of both curing agents. EPN was modified with polystyrene (EPN‐PS) and used as a matrix using an IPOX hardener. Nano‐ and hybrid composites were prepared with pristine and modified with tetramethylammonium chloride nano montmorillonite (NC and MNC), and red mud waste (RMW). The chemical structure was elucidated by the Fourier transform infrared (FT‐IR). The composites were characterized by scanning electron microscopy and x‐ray diffraction. Appropriate PS and NC ratio was accepted as 4% and 2% by weight, respectively. Curing degrees calculated from the FT‐IR spectra of ER, EPN, and EPN‐PS were 99.3%, 99.9%, and 86.5%, respectively. A comparative study of the two binary systems; (i) 2 wt% NC‐(15–35) wt% RMW; and (ii) 2 wt% of MNC‐(15–35) wt% of RMW on the mechanical, thermal, and flammability properties of EPN‐PS matrix was carried out. The appropriate RMW ratio was 30 wt%. Hybrid composites with 25–30 wt% RMW can be considered self‐extinguishing materials.

The effects of resin rate (wt-%) on different temperature performance of newly designed friction composites for automobile brake lining applications

ABSTRACT Choosing the amount of binder resin in a brake lining composition is important in terms of avoiding structural deterioration of the brake lining composite and resisting mechanical and thermal stresses at different temperatures. This study evaluated the performances of new brake lining composites with 15% and 20% novolac resin additives by performing wear tests in different temperature environments. Friction wear tests were performed according to ASTM G99 using pin-on-disc test devices at temperatures of 23°C, 150°C and 300°C. The hardness and density of the samples increased by 2.4% and 3.7%, respectively, with the increase of the novolac resin ratio in the composition. In general, it was observed that the friction coefficient, thermal conductivity and vibration increased in parallel with the resin ratio. In addition, increasing the test temperature led to an increase in the friction coefficient.

Recent progress in reinforcement of nanofillers in epoxy-based nanocomposites

Now a days, nanocomposites have brought the attentions due to their small dimensions, ultimate large surface area, along with large applications in industrial fields. This review gives detailed information about the epoxy composites and nanofillers to improve their crystallinity, nanostructures and mechanical strengths. Due to the presence of aromatic rings in the structure, epoxy polymer has heat and chemical resistance of high limit. Epoxy and their composites have large applications in coatings and aircrafts. Since their commercial inception in 1947 by the Devve-Raynolds Company, epoxy has become the most extensively studied, researched thermoset polymer. Bisphenol A and Epoxy Novolac Resins are most commonly used epoxy resins. Their multi functionality is about 2.5 to 6.0 which differs epoxy resins from standard Diglycidyl ether of Bisphenol A (DGEBA)based epoxy resins. Epoxy is preferred over other polymer matrix due to its high durability, chemical resistance and high adhesive properties. Currently modified epoxy resins are used in making of natural fibre reinforced composites and different instrumental parts in industries and aircrafts. This review also aims to give emphasis on the recent advancements in fabrication of epoxy polymer composites and their various strengths with respect to different concentration of nanofillers. As we know that formation of composite is an exothermic process, thus this review also carries the promise to enhance the thermal and electrical conductivity of the epoxy polymer by encapsulating suitable nanofillers with appropriate molecular wt%.

Sustainable Chitosan/Polybenzoxazine Films: Synergistically Improved Thermal, Mechanical, and Antimicrobial Properties.

Polybenzoxazines (Pbzs) are considered as an advanced class of thermosetting phenolic resins as they overcome the shortcomings associated with novolac and resole type phenolic resins. Several advantages of these materials include curing without the use of catalysts, release of non-toxic by-products during curing, molecular design flexibility, near-zero shrinkage of the cured materials, low water absorption and so on. In spite of all these advantages, the brittleness of Pbz is a knotty problem that could be solved by blending with other polymers. Chitosan (Ch), has been extensively investigated in this context, but its thermal and mechanical properties rule out its practical applications. The purpose of this work is to fabricate an entirely bio-based Pbz films by blending chitosan with benzoxazine (Bzo), which is synthesized from curcumin and furfuryl amine (curcumin-furfurylamine-based Bzo, C-fu), by making use of a benign Schiff base chemistry. FT-IR and 1H-NMR spectroscopy were used to confirm the structure of C-fu. The impact of chitosan on benzoxazine polymerization was examined using FT-IR and DSC analyses. Further evidence for synergistic interactions was provided by DSC, SEM, TGA, and tensile testing. By incorporating C-fu into Ch, Ch-grafted-poly(C-fu) films were obtained with enhanced chemical resistance and tensile strength. The bio-based polymer films produced inhibited the growth of Staphylococcus aureus and Escherichia coli, by reversible labile linkages, expanding Ch galleries, and releasing phenolic species, which was 125 times stronger than bare Ch. In addition, synthesized polybenzoxazine films [Ch/Poly(C-fu)] showed significant dose-dependent antibiofilm activity against S. aureus and E. coli as determined by confirmed by confocal laser scanning microscopy (CLSM). This study suggests that bio-based Ch-graft-polymer material provide improved anti-bacterial property and characteristics that may be considered as a possibility in the near future for wound healing and implant applications.