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•A bio-derived multifunctional additive (PPD) has been designed and synthesized.•6 wt% PPD enables PLA to achieve a desirable UL-94V-0 rating flame retardancy.•PPD improves the ...UV-resistance of PLA materials significantly at its low loading.•The addition of PPD leads to a 31% increase in the impact toughness of PLA.
Polylactic acid (PLA) represents one of most promising bioplastics in response to the increasing global microplastics pollution issue facing the entire ecosystem. Nevertheless, PLA is inherently flammable and also prone to UV-light attack, significantly restricting its wide applications in packaging, fibers and electronics industry. Despite high effectiveness in PLA, existing polyphosphate-based flame retardants are usually synthesized mainly from non-degradable petrochemical compounds and their functions are limited to improving flame retardancy of the polymeric matrix. We, herein, report the synthesis of a novel multifunctional bioderived polyphosphate (PPD) for PLA by using plant-derived diphenolic acid as a starting material. Our results reveal that the addition of 6 wt% of PPD enables PLA to achieve a desirable UL-94V-0 rating and a high LOI value of 27.1% due to its high gas-phase activity, which means that the final PLA fully meets the demanding flame retardancy requirement in industry. Moreover, the resultant flame-retardant PLA shows a high ultraviolet protection factor (UPF) value of 403, which indicates its excellent UV protection capability. Because of the fine and uniform dispersion of PPD within the resin matrix and their strong interfacial interactions, the PLA/6% PPD shows a 31% increase in impact toughness and a slight improvement in tensile strength compared to the bulk PLA. This work provides a strategy to synthesize a multifunctional bio-based polyphosphate flame retardant, which holds great promise for extending the practical applications of PLA with excellent flame retardancy, UV-blocking and mechanical performances.
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•Natural melanin particles were extracted from yak hair and used in developing a multifunctional coating on cotton fabric.•The natural melanin/PDMS coating on cotton showed a water ...contact angle of 164°.•The coated cotton fabrics possessed excellent UV protection and photothermal properties.•The natural melanin/PDMS coating showed high abrasion resistance and washing fastness.•The coated fabrics possessed high water vapor permeability.
This study presents a new approach to imparting the combined functionalities of superhydrophobicity, UV protection and personal thermal management via the photothermal effect to cotton fabrics. Surface modification of fabrics was carried out by applying coatings containing natural melanin (NM) particles extracted from yak hair and fluorine-free polydimethylsiloxane (PDMS) polymer via a dip-pad-dry-cure process. Different concentrations of NM particles were used in the coatings and the roles of each ingredient in achieving the desired functionalities were investigated. In addition, the relationship between NM content and the resultant durability of the coatings was explored based on the variations in superhydrophobicity, UV protection, photothermal performance, and color strength of the fabrics. The results demonstrated that the non-fluorinated NM/PDMS coatings were highly effective in developing a superhydrophobic cotton fabric with a water contact angle of 164°. The NM-coated fabrics provided a rapid heating effect under near-infrared light and their temperature increased to 38.4–45.3 °C, which was up to 14.7 °C higher than that of pristine cotton. Furthermore, the application of NM particles resulted in an excellent UV protection performance and generated the UV protection factor level of 198.48 on cotton fabrics. Finally, the coated fabrics were highly breathable and showed high stability against 1000 abrasion cycles, 5 accelerated washing tests, and 70 h UV irradiation. These findings provide new pathways in the development of future functional textiles using user-friendly and biocompatible ingredients.
•An effective and value-adding management of agricultural waste of fruit seeds.•Replacing toxic metal mordants with environmental friendly bio mordants.•Achieving a variety of color shades with ...enhanced color strength and fastness.•Achieving fabric bio-functions of UV protection, antioxidant and antibacterial properties.
As agricultural waste, fruit seeds have received little attention in producing natural colorant for textile dyeing application. This work uses Eriobotrya japonica L. seed skins (EJSS) as source of natural dye for the coloration and bio-functional finishing of wool fabric. Investigation has been made to the optimal extracting conditions (such as solvent system, pH, temperature and time) and natural dye characterization (chemical components, surface morphology, and thermal stability) using UV–vis, Fourier-transform infrared spectroscopy (FT-IR), Scanning electron microscope (SEM), thermogravimetric analysis (TGA), Energy Dispersive X-rays Spectroscopy (EDS) and Differential calorimetry (DSC). Flora leaves of Chinese Tallow, Folium Artemisiae Argyi and Cinnamomum Camphora were used to produce bio-mordants in this work. Pre-mordant fabric dyeing was conducted with comparisons made between bio-mordants and traditional metal ion mordants (ferrous sulfate, potassium aluminium sulfate, and copper sulfate). Results showed that pre-mordant dyeing using EJSS natural dye can produce wool fabric with a variety of shades with enhanced color strength, color fastness, and bio-functions (such as UV protection, antioxidant and antibacterial properties). Fabric mordanted with tannin-rich bio-mordant showed the best color strength and excellent functional behavior due to the high interaction between fiber and dye molecules activated by functional groups (such as phenolic groups). The outcome of this study can provide a potential to the application of agricultural waste to the natural dyeing of textile, as well as to a value-adding green waste management.
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•The multifunctional cellulose/silica hybrid microcapsules were prepared via one-step emulsion-solvent diffusion.•The multifunctional fabric coating system is water-based and ...environmental friendly.•The fabric coating exhibits excellent superhydrophobicity, ultraviolet resistant and thermal insulation.•These coatings demonstrate the self-healing ability of superhydrophobicity and ultraviolet protection after damaged.
Exploiting water-based fabric coatings outfitted with multiple protections (e.g., waterproofness, ultraviolet (UV) resistance and thermal insulation) are urgently demanded. Nevertheless, achieving the multifunction and durability poses the major challenge. In the present study, novel multifunctional cellulose/silica hybrid microcapsules were developed by one-step emulsion-solvent diffusion; these microcapsules were well dispersed into waterborne silicone resins to form waterborne multiple protective fabric coatings. Since the encapsulated phase change materials were in the core of capsules, and the hydrophobic coupling reagent and UV absorber were grafted onto the silicas in the shell of capsules, these fabric coatings exhibited high superhydrophobicity, UV protection and thermal insulation. Moreover, because hydrophobic coupling reagent and UV absorber in the shell-cellulose of capsules exhibited easy mobility, the fabric coatings displayed self-repairability of superhydrophobicity and UV protection even after being damaged chemically or mechanically. The fabric coating presented in this study could have a range of applications, covering special protective fabric, high-altitude garments as well as self-cleaning materials.
Homogeneous, translucent and flexible films of chitosan (CH) and ellagic acid (EA) were prepared by solvent casting. Various concentrations of EA (0.5, 1.0, 2.5 and 5.0% w/w relative to CH) were used ...in order to evaluate their UV-blocking properties. In addition, the photochemical stability of the films was also studied via artificial solar light irradiation. These set of films display high mechanical properties (Young’s modulus = 3.21–3.57 GPa), thermal stability up to 215–220 °C, UVA- and UVB-barrier properties, moderate water vapor permeability (WVP = 2.82–3.70 g mm m−2 day−1 kPa−1) and maximum antioxidant activity around 28% (DPPH scavenging activity). Furthermore, all CH/EA films show antimicrobial activity against food-borne pathogens such as Gram-positive (Staphylococcus aureus) and Gram-negative (Pseudomonas aeruginosa) bacteria due to the CH antimicrobial effectiveness. These bioactive UV-blocking CH/EA films open the way to materials with potential for eco-friendly active packaging.
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•Chitosan (CH) and ellagic acid (EA) films were prepared by solvent casting.•Homogeneous and flexible films with good mechanical and thermal properties.•Translucent CH/EA films display UV-blocking properties.•CH/EA films present high antioxidant and antimicrobial activities.•CH/EA films show great promise for eco-friendly active food packaging materials.
Lignin nanoparticles (LNP) have been esterified and etherified by citric acid and then blended with poly (vinyl alcohol) (PVA) at various loading levels (up to 10 wt%). Poly(vinyl alcohol) ...nanocomposite films containing unmodified and modified lignin nanoparticles (LNP and MLNP) were prepared through solvent casting approach. Microscopic investigation of films fractured surfaces confirmed that MLNP could be evenly dispersed in PVA matrix, and no macroscopic phase separation was generated in the nanocomposite films. Water contact angle, swelling efficiency and moisture adsorption properties of LNP and MLNP based films were measured and compared, revealing an overall increase of dimensional stability and reduced moisture adsorption for MLNP nanocomposites. MLNP based nanocomposite films outperformed the films containing LNP in antioxidant property and transparency, slight sacrificing in UV-absorbing, confirming these materials as promising candidates for applications requiring high antioxidant potential and improved performance towards light absorbance.
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•Chitosan act as mordant in dyeing.•Chitosan finish enhanced dyeing efficiency of cotton.•Chitosan and Onion skin dye improved Antibacterial and UV protection.
Interest in environment-friendly ...textile processing techniques has been augmenting in recent years. Natural dyes are environment friendly, low toxic and less allergenic owing to the existence of large number of structurally diverse active compounds which makes natural colourants promising options for the development of antimicrobial and ultra-violet (UV) protective textiles. The purpose of the present study was to investigate the effect of biopolymer and dyeing treatment with natural dye on the functional properties (antibacterial and UV protection) of cotton fabric and the assessment was done using standard test method. It was found that the chitosan treated onion skin dyed cotton fabric showed 97.20 percent and 98.03 % reduction in the growth of E. coli and S. aureus bacteria respectively. The chitosan treated dyed cotton fabric showed the higher ultra-violet protection factor (UPF) value (84.80) as compared to alum treated dyed cotton fabric (66.70) depicting that the chitosan treated dyed cotton fabric provided more ultraviolet protection than the alum treated dyed fabric.
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•A low loading intumescent microporous boron-based macrocycle flame retardant was successfully synthesized.•A UL-94 V-0 rating with an LOI value of 31.5% was achieved in addition to ...low CO and smoke production.•The composites attained excellent UPF rating compared to pristine PLA.•The tensile strength and the Young’s Modulus were enhanced by topological interlock mechanism.
A low loading microporous boron-based intumescent macrocycle (BMC) flame retardant (FR) was prepared and incorporated into PLA to reduce its flammability, improve the mechanical properties, and enhance its ultraviolet protection. Fourier transform infrared spectrum, scanning electron microscope, Raman spectroscopy, and N2 adsorption-desorption measurements were used to investigate the properties of BMC. The FR efficiency was evaluated by cone calorimeter, vertical burning test (UL-94), and limiting oxygen index (LOI). A maximum of 3 wt% BMC loading resulted in ~23%, and 37% reductions in the peak heat release rate and the total heat release, respectively. CO, CO2, total smoke release also reduced by ~71%, 26%, 56%, correspondingly. The fire performance index improved by ~41%, with an LOI value of 30.5% and a V-0 rating in the UL-94 test. The composites generally had excellent ultraviolet protection factor (UPF), whereas the pristine PLA could not pass the UPF rating. Raman spectroscopy analysis of the residual char showed increasingly robust amorphous intumescent glassy char content with the increasing BMC loading. The tensile strength and the Young’s Modulus increased by ~34% and 53%, respectively; however, the elongation at break got compromised marginally due to the limited polymer chain mobility resulting from the restricted in-plane and out of plane movements in the polymer matrix. Physical topology interlock was identified as the main mechanism for composite reinforcement. This work provides important insight into the use of sustainable low loading microporous boron-based intumescent flame retardant for improving the properties of PLA.
The integration of bio-based functional agents with biopolymers is welcomed as a way of meeting the growing demand for healthy, safety, and sustainability. This study presents a facile and ...solvent-free fabrication of flame retardant (FR), UV protective, and reinforced poly(lactic acid) (PLA) composite using two bio-based complexing couples: tannin acid/ferric salt (TAFe) and chitosan/phytic acid (CTSPA). The thermal and burning properties of PLA composites were evaluated by thermogravimetric analysis (TGA), limited oxygen index (LOI), UL-94 test, and cone calorimetry. The UV protective and tensile properties were also evaluated. PLA/TAFe and PLA/CTSPA showed earlier mass loss and higher char residue than pristine PLA. CTSPA (3 wt%) enhanced the LOI value of PLA from 19.6% to 30.5%. PLA/CTSPA and PLA/TAFe/CTSPA achieved V-0 ratings in UL-94 test with slight melt dripping. Cone calorimetry demonstrated that 2.5 wt% apiece of TAFe and CTSPA led to obvious reductions in peak heat release rate and total heat release. Interestingly, the combination of TAFe and CTSPA was effective in suppressing CO production. PLA/TAFe had a higher UPF value (50+) and tensile strength than pristine PLA. In conclusion, the sustainable strategy developed in this study represents the concept of fabricating fully bio-based polymer composites via a solvent-free process, which can also be generalized into the eco-design for other multifunctional polymer systems.
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•Simultaneously flame retarded, UV protective and reinforced PLA was fabricated.•Bio-based couples significantly enhanced the LOI value of PLA to 30.5%.•Flame retarded PLA composites achieved a V-0 rating in the UL-94 test.•Bio-based couples greatly reduced total heat release and CO production of PLA.•PLA/bio-based couple composites had a UPF value higher than 50.
•Marigold extract enhanced conductivity of solution and resulted in bead-free bent fibers.•PLA/Calendula bilayer membrane shows excellent mechanical strength and filtration stability.•Calendula ...alters microscopic arrangement of fibers and reduces UV transmittance.
The “dual carbon” strategy and the severe air pollution problem have spurred the development of environmentally friendly functional filters. However, the performance stability of degradable polymers under ultraviolet (UV) irradiation needs to be explored and addressed. Loading natural small molecules onto electrospun fibers can enhance their functionality and sustainability. This study explores the use of calendula extract to protect polylactic acid electrospun fibers from UV degradation and provide antibacterial properties. A double-layer filter was created using straightforward sequential electrospinning. Only one-third of the fiber membrane's thickness contains drugs, resulting in an 88 % inhibition rate against Staphylococcus aureus. Its UV protection capability has been significantly enhanced. The calendula filters exhibited a tensile strength loss rate of only 23 %, compared to 30 % for the unmodified filters. Furthermore, the calendula extract altered the morphology and porous structure of the fibers, leading to an enhancement in the stable filtration efficiency of the membrane. It maintains a filtration efficiency of over 99 % at a flow rate of 32–85 L/min. This study has enhanced the stable filtration capacity of biomass filters and showcased their potential for UV protection and antibacterial applications.
