Addition Of Fillers Research Articles

Profile of a Composite Based on Bacterial Cellulose and Polyvinyl Alcohol as a Drug Release Matrix for Tetracycline Hydrochloride

Bacterial cellulose (BC) is a natural polymer with good mechanical properties and hydrophilicity. Polyvinyl alcohol (PVA) is a synthetic polymer widely used in medicine. Both have been researched for their potential in drug release and acceptance. This study aims to determine the role of BC and PVA as drug release matrices for tetracycline hydrochloride (TCH), with additional fillers such as graphite (G) and TiO2. The results showed that the composites with BC matrix had lower mechanical properties than those with PVA matrix, with tensile strength values of 6.4075 and 17.446 MPa, respectively. However, the BC matrix was superior in porosity and swelling ability. The drug release testing of TCH from the composites showed that the appropriate model to describe drug release in BC matrix composites was in zero order, while the PVA matrix was in first order. The antibacterial activity of the composites on both matrices was tested against Staphylococcus aureus. The results indicate that both composites have potential applications in promising biomedical fields.

Upcycling PVC and PET as Volume-Enhancing Functional Fillers for the Development of High-Performance Bio-Based Rigid Polyurethane Foams

Polyvinyl chloride (PVC) and polyethylene terephthalate (PET) contribute significantly to global plastic waste, with only 9% recycled in recent years. In this work, these plastic wastes were upcycled as functional fillers to improve the rigid polyurethane foam (RPUF) properties. To attain this target, we leveraged the intrinsic polarity of the C=O and C-Cl groups of PVC and PET to induce intermolecular attractions with the N-H groups of the polyurethane matrix, evidenced by the observed IR peak shifts. This enhanced the nucleating effect during foaming, increasing the foams’ compressive strengths by 77% and 22% with the addition of 10% PVC and 5% PET filler, respectively. Furthermore, the addition of PVC and PET fillers increased the foam volume. Thus, the collective utilization of PPW and its corresponding impact on the CO-based RPUF’s properties signifies a reduction in carbon dioxide emissions by 14.15% and 17.52% for PVC and PET, respectively. Moreover, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) revealed improved thermal stability and degradation profiles of the produced RPUFs. Overall, this work highlights potential advancement in environmentally responsible upcycling strategies for common end-of-life plastic wastes, while enhancing rigid foam properties.

PREPARATION AND CHARACTERIZATION OF POLYMER INCLUSION MEMBRANES BASED ON BIODEGRADABLE CELLULOSE/ALGERIAN CLAY FOR HEAVY METALS REMOVAL FROM WASTEWATER

Separation membranes have gained attention as promising options for water and wastewater treatment due to their financial sustainability, and eco-friendliness. However, practical challenges have limited their application in water separation. To overcome these limitations, inorganic-organic hybrid membranes have been developed in this study. The present work deals with two attractive aspects: (i) economical, through the valorization of a local clay (Algerian kaolin), and (ii) environmental, which is based on the membrane selectivity for metal ions. The principal objective of this work is the development of enhanced nanocomposite membranes. It is achieved with low costs, based on cellulose triacetate (CTA) as a polymeric matrix modified by the addition of a lamellar filler, i.e. yellow clay obtained from Jijel, located in the east of Algeria, and plasticized by dioctyl phthalate (DOP). A further objective of this paper was the treatment of wastewater polluted by lead (Pb2+) and cadmium (Cd2+). The prepared membranes were characterized by various characterization techniques, including scanning electron microscopy (SEM), Fourier-transform infrared (FTIR) spectroscopy and thermogravimetric analysis (TGA). All synthetized membranes had an amorphous structure, with homogeneous pore morphology and distribution. Moreover, the presence of nanocomposite clay showed effective integration into the membrane matrix and led to a significant improvement in thermal resistance. These membranes were applied to treat a synthetic aqueous solution contaminated with heavy metals, namely Pb2+ and Cd2+. The results revealed a rejection rate higher than 50%, suggesting the potential effectiveness of a stable and environmentally sustainable polymer inclusion membrane system for water purification.

Environmental sustainability and waste conversion of Prosopis juliflora fibre-reinforced ZnO nanofiller particulates PLA composite- mechanical and thermal analysis

The presence of large quantities of Prosopis juliflora (PJ) fibers in natural habitats presents substantial threats to the environment and economies of numerous developing countries. Utilizing natural fibers in polymer composites can effectively enhance their characteristics. The primary objective of this study is to create a composite material by combining Prosopis Juliflora (PJ) fiber with a polylactic matrix that has been combined with zinc oxide nanofillers. The fabrication process will involve the hand layup technique. In order to have a comprehensive understanding of the mechanical characteristics, thermal behavior, and thermal stability of the PJ composite, it is necessary to undertake additional investigations. The results showed that the inclusion of zinc oxide filler enhanced the tensile strength (67.29 MPa), flexural strength (64.27 MPa), compressive strength (56.79 MPa), and impact energy (34 J) in sample S5. Additionally, the thermal properties, including thermal conductivity, thermal expansion, and short-term heat resistant capacity, were also improved by the addition of zinc oxide filler in sample S5. The deterioration temperature of the PJ composite was determined to be between 312 and 342 °C using thermogravimetric analysis. The failure mode of the PJ composite was investigated using scanning electron microscopy.

Effect of wheat bran filler particulates nettle fiber reinforced epoxy matrix composite − A novel material for thermal insulation application

This research examines the mechanical and thermal characteristics of composites made from nettle fiber-reinforced wheat bran filler particulate epoxy framework. It highlights the influence of different filler materials on the performance of these composites. A thorough examination of mechanical properties was carried out, focusing on the flexibility, bending strength, impact resistance, and Shore D hardness. The malleable quality was completely changed by adding a filler ingredient, reaching a peak of 51.36 MPa. The flexural strength reached 47.38 MPa, showing excellent ability to withstand loads. The assessment of affect quality reached a maximum of 13 kJ/m2, indicating high energy absorption and durability. The Shore D hardness, which indicates the surface’s ability to resist indentation, ranged from 52 to 61, indicating differences in the stiffness of the composite material. The addition of bran filler to this composite provides an ideal thermal conductivity value of 0.98 W/mK. The morphological properties of the composites were analysed using Scanning Electron Microscopy (SEM), which provided detailed insights into their internal structure. The SEM images revealed a uniform distribution of nettle filaments and bran fillers inside the epoxy matrix, with well-formed samples exhibiting strong fiber–matrix adhesion and minimal voids.

The Influence of Diatomite on the Sound Absorption Ability of Composites.

Diatomites are well-known mineral materials formed thousands of years ago from the skeletons of diatoms. They are found in many places around the world and have a wide range of applications. This article presents innovative research related to the possibility of using diatomite as a filler in composites to improve their sound absorption properties. The results of the study of the effect of diatomite processing (calcination) and its degree of fineness on the sound absorption coefficient of thermoplastic composites are presented. Three fractions of diatomite (0 ÷ 0.063 mm; 0.5 ÷ 3 mm; 2 ÷ 5 mm) and its variable mass proportion (0, 25, and 50 wt.%) were used. The composites were made with flax fibers as a reinforcement, polylactide as a matrix, and diatomite as an additional filler. This paper also presents the results of oxide chemical composition, diatomite mineral phase composition, morphology, and thermal conductivity coefficient of all diatomite fractions studied. In addition, the average particle size for diatomite powder was also determined. The most important of the studies was the determination of the acoustic properties of the aforementioned composites. As a result of the tests, it was found that the smallest fraction of diatomite particles and a variant without thermal treatment give the best effect in terms of sound absorption.

Characterization and application of fine aggregate from Rio Branco do Sul – PR with quartz filler additions: innovations in concrete performance

Understanding the properties of a material is essential to ensure its efficient application and achieve good results. This study addresses the characterization and applicability of quartz sand from the Rio Branco do Sul region, Paraná (PR), Brazil, in civil construction, focusing on procedures such as ceramic block laying, plastering, and rendering. Additionally, quartz filler (quartz powder) was added as a pozzolanic additive in fractions of 10% and 20% relative to the weight of the cement, along with samples without additives, to compare the results. To evaluate performance, the test specimens were subjected to two curing processes: thermal curing, aimed at activating pozzolanic reactions between the quartz powder and the chemical components of the concrete; and wet curing, which, although it does not stimulate chemical reactions, preserves the physical effects of the addition, such as reducing the concrete’s porosity and increasing its compressive strength. The specimens were analyzed at 7, 14, 21, and 28 days of age.

Epoxy composite dust reinforced novel polypropylene composites: An eco‐friendly approach toward sustainable resource management

AbstractThis study presents an innovative technique for recycling leftover epoxy composites reinforced with natural fillers. The waste epoxy composites were successfully ground into a 75–150 μm fine powder. With the aid of extrusion injection molding, this powder was subsequently utilized to create polypropylene matrix‐based polymer composites with variable filler loadings ranging from 10% to 30%. The mechanical, thermal, thermomechanical, and morphological properties of the developed composites were assessed. The greatest tensile strength of the polypropylene composites produced with 10% filler loading was found to be 24.15 MPa. The addition of epoxy composite filler increased the thermal stability. During morphological investigations, it was discovered that pits, voids, and filler agglomerations predominated the fractured surface of the developed composites. Overall, it can be concluded that there is a lot of promise for value‐added recycling of thermosetting resin‐based composites using this low‐cost, high‐efficiency, and ecologically benign process, which would lessen the environmental impact of plastic.Highlights Novel polypropylene composites using epoxy composite dust was developed. Mechanical, thermal, thermomechanical, and morphological studies were performed. Toys, tableware, mementos, and furniture can be the potential applications. The developed composites can reduce plastic load on the environment.

Research on the Microstructures and Properties of AA5052 Laser-Welded Joints with the ER4043 Filler Wire

Researches were conducted on the laser welding of 3 mm sheet-thickness lap joints of AA5052 with ER4043 filler wires. The effects of laser power on the joint morphology, microstructure, mechanical properties, and corrosion resistance were investigated. The results indicate that both increased heat input and the addition of filler wires make the molten pool more instable, which results in more process pores. Circular pores are observed in the upper part of the weld, while chain-like pores are distributed in the middle of the weld. The highest tensile strength of the weld joint is 192.61 MPa with an elongation of 10.1% at a laser power of 3.5 kW. The microhardness at the center of the weld is approximately 25% higher than the base material, which is probably because the addition of ER4043 filler wires brings more Si element to the weld. Moreover, the weld joints display superior corrosion resistance compared to the base material. These outcomes enhance the understanding of AA5052 laser welding with fillers wire and provide valuable in-sights for engineering applications.

Investigating the Impact of 3D Printing Parameters on Hexagonal Structured PLA+ Samples and Analyzing the Incorporation of Sawdust and Soybean Oil as Post-Print Fillers

Today, around the world, there is huge demand for natural materials that are biodegradable and possess suitable properties. Natural fibers reveal distinct aspects like the combination of good mechanical and thermal properties that allow these types of materials to be used for different applications. However, fibers alone cannot meet the required expectations; design modifications and a wide variety of combinations must be synthesized and evaluated. It is of great importance to research and develop materials that are bio-degradable and widely available. The combination of PLA+, a bio-based polymer, with natural fillers like sawdust and soybean oil offers a novel way to create sustainable composites. It reduces the reliance on petrochemical-based plastics while enhancing the material’s properties using renewable resources. This study explores the creation of continuous hexagonal-shaped 3D-printed PLA+ samples and the application of post-print fillers, specifically sawdust and soybean oil. PLA+ is recognized for its eco-friendliness and low carbon footprint, and incorporating a hexagonal pattern into the 3D-printed PLA+ enhances its structural strength while maintaining its density. The addition of fillers is crucial for reducing shrinkage and improving binding capabilities, addressing some of PLA+’s inherent challenges and enhancing its load-bearing capacity and performance at elevated temperatures. Additionally, this study examines the impact of varying filler percentages and pattern orientations on the mechanical properties of the samples, which were printed with an infill design.

Plasticized PVC composites comprising MWCNT‐RGO hybrid filler–the synergetic effect of hybrids on the dielectric and mechanical properties

AbstractModification of polymers with hybrid fillers has sought much attention in the past few years. The addition of hybrid fillers will lead to a synergistic effect in reinforcing and is advantageous in polymer nanocomposites. One such attempt is presented here that explores the effect of incorporation of hybrid derived from reduced graphene oxide (RGO) and multiwalled carbon nanotubes (MWCNT) on the dielectric and mechanical properties of plasticized polyvinyl chloride (PPVC). This system of hybrid composite incorporating RGO‐CNT and PPVC has not been prepared and reported yet. Melt mixing techniques were effectively used for the fabrication of PPVC nanocomposites containing the hybrid filler in different ratios. The prepared composites showed enhanced dielectric strength in the lower frequency region up to 450 and high AC conductivity. The mutual stacking and penetration of the 1D‐2D nanomaterials lead to effective dispersion and enhancement in the electronic conduction. Among the hybrids, the R1C5 (with the filler ration RGO 1 wt% and CNT 5%) was having the optimum properties. The tensile modulus showed a cumulative variation with the addition of CNT. Even though the tensile strength decreased slightly because of the immobilization of the PPVC chains by the hybrid effect, the modulus value showed a marked increase of over 90% from the virgin polymer. The PPVC composite with R1C5 hybrid filler exhibited an EMI shielding efficiency of ⁓23 dB and it was frequency independent. The results suggest the composite R1C5 should be used as a cost‐effective material for applications in the L‐band and S‐band regions.

Bio-functionalization of fillers with natural phytic acid for sustainable flame-retardant agents for natural rubber composites

The current challenge for sustainable flame retardants has led to innovative approaches, including the utilization of natural substances to enhance the fire resistance of elastomer composites. This paper presents the design of eco-friendly hybrid flame-retardant additives based on mineral fillers (hydrotalcite (LDH) and sepiolite (SEP)) modified with aminosilane (APTS) and phytic acid (PA) for natural rubber (NR) biocomposites. The synergistic effects of the PA and silanized mineral fillers resulted in NR composites with improved thermal, mechanical, and barrier properties, as well as increased flame retardancy. Importantly, it was proven that direct in-situ application of PA into elastomer cured with sulphur-based crosslinking systems is ineffective, due to its negative effect on the curing process (significantly reducing torque moment). Binding the PA onto silanized fillers enabled the creation of hybrid additives that leverage the flame-retardant benefits of PA without compromising the other properties of the polymer. The addition of PA-modified fillers to NR reduced the heat release rate (HRR) by around 40 %, indicating outstanding flame retardancy. This work makes a significant contribution and expands the understanding of using eco-friendly natural compounds to reduce the flammability of sulfur-cured elastomers.

Mechanical and Thermal Properties of Epoxy Resin upon Addition of Low-Viscosity Modifier.

Thermoset-based polymer composites containing functional fillers are promising materials for a variety of applications, such as in the aerospace and medical fields. However, the resin viscosity is often unsuitably high and thus impedes a successful filler dispersion in the matrix. This challenge can be overcome by incorporating suitable low-viscosity modifiers into the prepolymer. While modifiers can aptly influence the prepolymer rheology, they can also affect the prepolymer curing behavior and the mechanical and thermal properties of the resulting matrix material. Therefore, this study investigates the effects that a commercial-grade low-viscosity additive (butyl glycidyl ether) has on a common epoxy polymer system (diglycidyl ether of bisphenol-A epoxy with a methylene dianiline curative). The weight percentage of the modifier inside the epoxy was varied from 0 to 20%. The rheological properties and cure kinetics of the resulting materials were investigated. The prepolymer viscosity decreased by 97% with 20 wt% modifier content at room temperature. Upon curing, 20 wt% modifier addition reduced the exothermic peak temperature by 12% and prolonged the time to reach the peak by 60%. For cured material samples, physical and thermo-mechanical properties were characterized. A moderate reduction in glass transition temperature and an increase in elastic modulus was observed with 20 wt% modifier content (in the order of 10%). Based on these findings, the selected material system is seen as an expedient base for material design due to the ease of processing and material availability. The present study thus provides guidance to researchers developing polymer composites requiring reduced prepolymer viscosity for successful functional filler addition.

Influence of non-linear diffusion controlled phenomena on the sorption capability of PEO-Salt-SiO2 composite electrolyte: A study on property optimization

The present research, reports the hygrothermal behavior of poly [ethylene oxide] (PEO) based composite film (500 and1000 μm) containing NH4I and KBr (5–20 wt%) as the mobile phase and non-reactive silica (15 wt%) as the filler. These are termed as PK/NSiO2-series for solvent sorbed and (PK/NSiO2)NS for non-swelled film. The novelty of the research lies in the analyses of non-Fickian solvent diffusion trait of films using python programming. The presence of ions and its variable polarizable nature is found to influence the number density of bonded and free solvent content along with the extend of cross linkage. Introduction of silica is found to enhance the ionic conductivity (about one order higher) of the film irrespective of the type of charge carrier owing to the improved dispersion within the matrix. Non-Fickian diffusion is found to influence the ionic conductivity of P2K20SiO2 (10−5Scm−1 to 10−2 Scm−1) minimizing the degradation to 0.2 %ΔC/1000 h (>1 %ΔC/1000 h, tested for 2000 h) compared to P2N20NSiO2. In contrast, ion migration in P2NSiO2 is guided by Rice and Roth model and being more polarizable ions, the mobility is significant which maximizes the conductivity to ∼10−1 Scm−1. Microstructural study shows heterogenous nucleation to be more pronounced upon addition of silica filler wherein the homogeneity, inter fibrillar interaction and grain growth of spherulites is higher. This tends to extend amorphous regions thereby propagating the ion migration path. The influence of sorption process is studied in terms of electrochemical impedance, dielectric analyses and long term cyclability (20,000 h) in terms of loss tangent.

Utilization of spent bleaching earth as green filler and plasticizer in the manufacture of rubber compounds for solid tire production

This study utilized spent bleaching earth (SBE) as a single form of filler and plasticizer in the manufacture of rubber components for solid tire vulcanizate. SBE, an underutilized byproduct of vegetable oil purification, is abundantly available globally and can be used as a filler and plasticizer in rubber compounds. This aligns with environmental sustainability principles, reduces disposal costs, and lowers raw material expenses in rubber manufacturing. In this research, the SBE was applied for each formula from SBE-02 to SBE-05 at ratios of 15–30 per hundred rubber (phr). As a comparison, carbon black (CB) filler (65 phr), CaCO3 (35 phr), and plasticizer derived from petroleum in the form of paraffinic oil (PO) (6 phr) were used. Rubber components were produced by masticating natural and synthetic rubber in an open mill, followed by the addition of filler, plasticizer, accelerator, co-activator, anti-degradant, and vulcanization agent. The resulting compounds were vulcanized at 150 °C and 10 MPa for 17 minutes. The test results demonstrated that incorporating SBE at a ratio of 15 phr (SBE-02) significantly reduced the cure time (t90) to 8 minutes and 20 seconds, the shortest among all tested formulations. The mechanical properties of the SBE-02 vulcanizate rubber met the requirements for solid wheelchair tire applications, with a hardness of 70 Shore A. However, its abrasion resistance test result of 189.1 g/cm³ was the lowest among the formulations tested. Furthermore, the scorch time (ts2) of the SBE-02 was determined to be 2 minutes and 35 seconds. Results from a 1000x magnification scanning electron microscope (SEM) reveal air gaps on all sample surfaces of different sizes. The elements C, O, Zn, Si, Ca, and Pb dominate the SEM-EDX results for all rubber vulcanizate samples from all three spectra, in varying weight percentages. The identification of functional groups with FTIR on all rubber vulcanizate samples shows Si–O–Si bending at 2, 4, and 5 and Si–O–Al stretching at 3, 5 on the wave number spectrum of 680–413 cm−1 Si–O–Si on the wave number spectrum 1100–1050 cm−1 from the infrared spectrum.

Effect of the Addition of Inorganic Fillers on the Properties of Degradable Polymeric Blends for Bone Tissue Engineering.

Bone tissue exhibits self-healing properties; however, not all defects can be repaired without surgical intervention. Bone tissue engineering offers artificial scaffolds, which can act as a temporary matrix for bone regeneration. The aim of this study was to manufacture scaffolds made of poly(lactic acid), poly(ε-caprolactone), poly(propylene fumarate), and poly(ethylene glycol) modified with bioglass, beta tricalcium phosphate (TCP), and/or wollastonite (W) particles. The scaffolds were fabricated using a gel-casting method and observed with optical and scanning electron microscopes. Attenuated total reflectance-Fourier transform infrared (ATR-FTIR), differential scanning calorimetry (DSC), thermogravimetry (TG), wettability, and degradation tests were conducted. The highest content of TCP without W in the composition caused the highest hydrophilicity (water contact angle of 61.9 ± 6.3°), the fastest degradation rate (7% mass loss within 28 days), moderate ability to precipitate CaP after incubation in PBS, and no cytotoxicity for L929 cells. The highest content of W without TCP caused the highest hydrophobicity (water contact angle of 83.4 ± 1.7°), the lowest thermal stability, slower degradation (3% mass loss within 28 days), and did not evoke CaP precipitation. Moreover, some signs of cytotoxicity on day 1 were observed. The samples with both TCP and W showed moderate properties and the best cytocompatibility on day 4. Interestingly, they were covered with typical cauliflower-like hydroxyapatite deposits after incubation in phosphate-buffered saline (PBS), which might be a sign of their excellent bioactivity.

Influence of Gamma-Phase Aluminum Oxide Nanopowder and Polyester-Glass Recyclate Filler on the Destruction Process of Composite Materials Reinforced by Glass Fiber.

Recycling of composite materials is an important global issue due to the wide use of these materials in many industries. Waste management options are being explored. Mechanical recycling is one of the methods that allows obtaining polyester-glass recyclate in powder form as a result of appropriate crushing and grinding of waste. Due to the fact that the properties of composites can be easily modified by adding various types of fillers and nanofillers, this is one of the ways to improve the properties of such complex composite materials. This article presents the strength parameters of composites with the addition of fillers in the form of polyester-glass recyclate and a nanofiller in the form of gamma-phase aluminum nanopowder. To analyze the obtained results, Kolmogorov-Sinai (K-S) metric entropy was used to determine the transition from the elastic to the viscoelastic state in materials without and with the addition of nanoaluminum, during a static tensile test. The tests included samples with the addition of fillers and nanofillers, as well as a base sample without any additives. The article presents the strength parameters obtained from a testing machine during a static tensile test. Additionally, the acoustic emission method was used during the research. Thanks to which, graphs of the effective value of the electrical signal (RMS) were prepared as a function of time, the parameters were previously identified as extremely useful for analyzing the destruction process of composite materials. The values obtained from the K-S metric entropy method and the acoustic emission method were plotted on sample stretching graphs. The influence of the nanofiller and filler on these parameters was also analyzed. The presented results showed that the aluminum nanoadditive did not increase the strength parameters of the composite with recyclate as a result of the addition of aluminum nanofiller; however, its addition influenced the operational parameters, which is reflected in a 5% increase in the UTS value (from 55% to 60%).

PEBAX® 5533D Formulation for Enhancement of Mechanical and Thermal Properties of Material Used in Medical Device Manufacturing

The medical device industry is constantly innovating in the search for materials that demonstrate superior performance, better intrinsic characteristics, profitability, and a positive impact on potential patients. The thermoplastic polymer resin Pebax® 5533D is one of the most widely used commercial materials for manufacturing medical device parts due to its easy processability. However, its mechanical and thermal properties require improvements to mitigate identified manufacturing defects, such as a decrease in material flexibility, high susceptibility to moisture, and thermal degradation during processing. Therefore, this study integrated different materials, such as plasticizers and filler additives, to produce a polymer compound prototype formula as a solution technique to enhance the current material’s performance. Modifying mechanical and rheological properties allows to evaluate the impacts on the polymeric material’s flexibility and thermal behavior. This was achieved by processing mixed additives using injector-molding equipment to obtain equal-molded samples of every formula. In addition, material characterization was performed to determine the variations in the samples’ crystallization, flexural strength, and moisture content. Calcium stearate was determined to be the most significant component serving as a mechanical resistance modifier and thermal stabilizer alongside calcium chloride as a moisture content reducer combined with Pebax® 5533D.

Degradation mechanism of atrazine in water by permutit loaded Fe and Cu oxides in a multi-electrode dielectric barrier discharge reactor

In this paper, the degradation of ATZ (Atrazine) in water by a catalyst-filler synergistic multi-electrode DBD (Dielectric barrier discharge) reactor was investigated.The results showed that 1O2, ·O2- and ·OH played a major role in the degradation process of ATZ. The addition of catalyst filler accelerated the removal efficiency of ATZ, and the removal efficiency of ATZ in Fe2O3/Permutit+DBD, CuO/Permutit+DBD, and Permutit+DBD were 95.76 % at the input voltage, gas flow rate, dosing volume, and processing time of 34 kV, 100 L/h, 1 g, and 15 min, respectively, 94.85 % and 91.54 %, which was 15 min shorter than the processing time of DBD system alone. Eight major degradation products were detected by high-resolution mass spectrometry, and their possible degradation pathways were inferred by combining with the DFT, and their intermediate products were found to be less acutely toxic and less chronically toxic than the parent ATZ by the ECOSAR toxicity analysis software.

Fabricating coconut palm-based rigid polyurethane foam with enhanced compressive strength using biomass waste

The continued depletion of fossil fuels compels the exploitation of biomass as alternative. Herein, coconut palm, as a common tropical biomass, was first used to prepare polyether polyols via liquefaction method. The obtained polyether polyols were employed to fabricate rigid polyurethane foam (RPUF), which is widely applied in the industry. Moreover, the prepared RPUF was further modified by biomass waste including coconut shell (CS), coconut palm (CP), and seaweed (SE), with the contents of 5–15 wt%. The results showed that the addition of fillers can decrease the apparent densities and increase the compressive strength of the foams. The foam modified with 15 wt% CS exhibits the highest compressive strength with a value of 355 kPa and normalized value of 290 kPa among the prepared RPUF. In addition, an appropriate content of fillers can slightly increase the thermal stability of RPUF. The combustion performance test indicates that the introduction of fillers slightly increases the oxygen index value of coconut-based polyurethane, which produces less smoke than unmodified foam. Compared with the HRR of unmodified foam, the HRR of RPUF modified with CP are higher while those modified with SE are smaller. The foams modified with SE exhibit the optimal flame-retardant property. This work provides a novel and sustainable route to prepare and modify bio-based RPUF, which can furnish a clue to prepare bio-based RPUF with desirable performance.