Rate Of Product Release Research Articles

Extraction of fucoidan and alginate from Sargassum thunbergii using dimethylamine solution: Insights into the process and mechanism

The utilization of algal ingredients for producing functional products has garnered significant attention. Furthermore, increasing the yield of polysaccharides has become a crucial point. In this work, the efficiencies of two-step extraction and co-extraction were compared, and dimethylamine solution was selected as the optimal extractant. Under the optimum extraction conditions (temperature of 75.00 °C, time of 3.15 h, liquid-solid ratio of 35.00 mL/g) determined by response surface methodology, the yield of alginate was 16.05 ± 0.37 % and the yield of fucoidan was 2.85 ± 0.08 %. Kinetic analysis of the extraction process was conducted using the shrinking core model, elucidating the rate and mechanism of product release. Additionally, it was demonstrated that the dimethylamine solution could be recycled for five times with stable extraction performance. The extraction mechanism was further analyzed by quantum chemical calculations, providing theoretical support for the extraction process of the products. The above results demonstrated that the higher yield of products extracted with dimethylamine was confirmed through experimental and quantum chemical analysis. Overall, this study provides a new perspective on the extraction of alginate and fucoidan from seaweed.

Multi-functional flame-retardant epoxy resin featuring diverse crosslinking networks

High-performance epoxy resins (EPs) with ultimate flame retardancy, particularly in terms of smoke suppression (as asphyxiation is the primary cause of death in fires), remain a significant challenge. To address this issue, we propose a feasible multiple crosslinking strategy by incorporating an additive flame retardant (abbreviated as BPPDN) containing self-crosslinking groups to construct multi-crosslinking networks during the curing of EPs. Using this strategy, the BPPDN/EP flame-retardant samples achieved a V-0 rating in the UL-94 test in the absence of conventional flame-retardant elements such as halogens or phosphorus. Among the rest, 15BPPDN/EP had remarkable low fire hazards, with total smoke production and peak heat release rate reduced by 38.7 % and 22.2 %, respectively. Surprisingly, the 15BPPDN/EP material maintained its high transparency, excellent ultraviolet shielding, and dielectric properties (specifically, the dielectric constant decreased from 5.19 to 3.46; the dielectric loss decreased from 0.0066 to 0.0045), as well as its ultrahigh tensile strength (increased by 63 %), flexural strength (by 48 %) and impact strength (by 75 %). This paper investigates in detail the effects of BPPDN on the curing process, thermal properties, mechanical properties, dielectric properties, and flame retardancy of EPs, providing a new direction for the design of highly transparent, multifunctional high-performance flame-retardant thermosetting resins without the need for conventional flame-retardant elements.

Exploring Product Release from Yeast Cytosine Deaminase with Metadynamics.

The yeast cytosine deaminase (yCD) enzyme/5-fluorocytosine prodrug system is a promising candidate for targeted chemotherapeutics. After conversion of the prodrug into the toxic chemotherapeutic drug, 5-fluorouracil (5-FU), the slow product release from the enzyme limits the overall catalytic efficiency of the enzyme/prodrug system. Here, we present a computational study of the product release of the anticancer drug, 5-FU, from yCD using metadynamics. We present a comparison of the 5-FU drug to the natural enzyme product, uracil. We use volume-based metadynamics to compute the free energy landscape for product release and show a modest binding affinity for the product to the enzyme, consistent with experiments. Next, we use infrequent metadynamics to estimate the unbiased release rate from Kramers time-dependent rate theory and find a favorable comparison to experiment with a slower rate of product release for the 5-FU system. Our work demonstrates how adaptive sampling methods can be used to study the protein-ligand unbinding process for engineering enzyme/prodrug systems and gives insights into the molecular mechanism of product release for the yCD/5-FU system.

Development of alginate beads for precise environmental release applications: A design of experiment based approach and analysis

Controlled release of active ingredients are important for drug delivery and more recently environmental applications including modulated dosing of chemical and biological controls. This study demonstrates the importance of investigating various material science factors that can influence the diffusion rates of alginate beads to improve and tune their performance for marine environmental applications. This investigation aimed to design a rational workflow to aid in leveraging alginate bead use as a carrier matrix for releasing a specific active agent into water. Experiments were conducted to focus on the narrow a large list of relevant material formulation parameters, which included chitosan molecular weight, chitosan concentration, calcium concentration, drop height, and bead size. Once the most relevant material preparation methods were screened, a more robust statistic Design of Experiments approach was performed and results determined the important (and unimportant) factors for increasing dye release kinetics in marine water. The process was further streamlined by narrowing the critical experimental factors to a three-level based on the prior analysis: chitosan MW, chitosan concentration, and bead size. Analysis of the collected data indicated that while chitosan MW had a negligible impact (Fstatistic = 0.22), bead size (Fstatistic = 60.33) significantly influenced the diffusion rates based on surface area. However, chitosan MW had minor effects where lower chitosan MW enabled higher product release rates. This case investigation was a novel application of the design of experiment approach towards environmental applications to understand differences in release rates to marine waters for the first time and the workflow provided also serve as the basis for researchers to optimize other environmental applications requiring optimization when it is unknown how a large number of formulation variables will impact performance in different environmental scenarios.

Heterostructured MXene/alginate coating for fire warning and protection: Preparation and characterization

Cotton fabrics with intelligent fire warning and protection have promising applications in smart wearables and smart home decoration. In this study, multifunctional nanoparticles (M@A) with heterogeneous structures are constructed through the electrostatic self-assembly of core-shell structured silver nanowires (AgNW@BP) and MXene nanosheets. Subsequently, M@A is blended with bio-based sodium alginate (SA) to prepare multifunctional cotton fabrics that exhibit fire warning, thermal conductivity, high strength, and flame retardancy. For instance, the tensile strength of the multifunctional fabric is 58.5 MPa, surpassing that of some MXene paper/films used for fire warning (~10 MPa). Furthermore, the catalytic charring effect of AgNW@BP and the labyrinth effect of MXene synergistically enhances the flame retardancy of the multifunctional cotton fabric (total heat release rate, total smoke production and peak heat release rate of the multifunctional cotton fabric are 5.7 MJ/m, 0.09 m2, and 126.8 kW/m2, respectively). Significantly, the multifunctional cotton fabric also demonstrates a fast response time (2 s) and repeatable alarm capability when exposed to flames attack.. Hence, this work provides inspiration for the design and fabrication of multifunctional cotton fabrics with intelligent fire warning and protection.

Facile synthesis of phosphorus-containing benzotriazole flame retardant for enhancement of mechanical and fire properties of epoxy resins

The preparation of flame retardant, strong yet tough, and transparent epoxy resin (EP) composites faces significant challenge. In this study, a phosphorus-containing benzotriazole flame retardant PDI was successfully synthesized. It was important to highlight that the EP/PDI-11 % achieved a limiting oxygen index (LOI) of 32 % and was classified as UL-94V-0 rating. Furthermore, it exhibited a significant reduction in both total smoke production (TSP) and peak heat release rate (pHRR), which decreased by 64.1 % and 46.9 % respectively when compared to EP. Meanwhile, PDI simultaneously enhanced the mechanical strength and toughness of EP, and adding 5 wt% PDI resulted in a 27.2 % improvement in tensile strength, a 53.3 % increase in elongation at break and a 91.4 % increase in impact strength for EP-5 %. Notably, PDI had the ability to promote curing, and the curing peak temperature of EP was advanced by about 20 ℃. In addition, PDI enhanced the insulation and UV resistance properties of EP/PDI, and the high transparency of EP/PDI composites also maintained.

Behaviour of concrete building units incorporating waste plastic eco-aggregate (RESIN8) subjected to fire conditions

Plastic waste has started to be incorporated within construction systems with potential benefits including improved sustainability, decreased costs, lighter construction units and enhanced thermal performance. However, the addition of plastics has an unknown impact on the fire response and associated behaviour of recycled construction products. Hence, this work seeks to answer the question: does the incorporation of waste plastic in masonry systems influence fire risk? This study investigates the effect of using the RESIN8 eco-aggregate in bricks, an aggregate based on processed waste plastic. This is done by exposing concrete bricks containing 0%, 5%, 10%, 20%, 30%, 40% and 50% RESIN8 by volume to a heat flux of 30 kW/m2 for an hour. The replacement content of the RESIN8 samples influenced both smoke production and mass loss rates, with high volumes of smoke observed for the highest replacement content of RESIN8. The capacity of the RESIN8 brick units was also found to drop by up to 34.7% of the original compressive strength. It is shown that low replacement rates (e.g. 5 and 10%) are unlikely to affect fire risk significantly, but higher replacement rates may be a concern due to smoke production and heat release rates.

Catalytic Cycle of the Bifunctional Enzyme Phosphoribosyl-ATP Pyrophosphohydrolase/Phosphoribosyl-AMP Cyclohydrolase.

The bifunctional enzyme phosphoribosyl-ATP pyrophosphohydrolase/phosphoribosyl-AMP cyclohydrolase (HisIE) catalyzes the second and third steps of histidine biosynthesis: pyrophosphohydrolysis of N1-(5-phospho-β-D-ribosyl)-ATP (PRATP) to N1-(5-phospho-β-D-ribosyl)-AMP (PRAMP) and pyrophosphate in the C-terminal HisE-like domain, and cyclohydrolysis of PRAMP to N-(5'-phospho-D-ribosylformimino)-5-amino-1-(5″-phospho-D-ribosyl)-4-imidazolecarboxamide (ProFAR) in the N-terminal HisI-like domain. Here we use UV-VIS spectroscopy and LC-MS to show Acinetobacter baumannii putative HisIE produces ProFAR from PRATP. Employing an assay to detect pyrophosphate and another to detect ProFAR, we established the pyrophosphohydrolase reaction rate is higher than the overall reaction rate. We produced a truncated version of the enzyme-containing only the C-terminal (HisE) domain. This truncated HisIE was catalytically active, which allowed the synthesis of PRAMP, the substrate for the cyclohydrolysis reaction. PRAMP was kinetically competent for HisIE-catalyzed ProFAR production, demonstrating PRAMP can bind the HisI-like domain from bulk water, and suggesting that the cyclohydrolase reaction is rate-limiting for the overall bifunctional enzyme. The overall kcat increased with increasing pH, while the solvent deuterium kinetic isotope effect decreased at more basic pH but was still large at pH 7.5. The lack of solvent viscosity effects on kcat and kcat/KM ruled out diffusional steps limiting the rates of substrate binding and product release. Rapid kinetics with excess PRATP demonstrated a lag time followed by a burst in ProFAR formation. These observations are consistent with a rate-limiting unimolecular step involving a proton transfer following adenine ring opening. We synthesized N1-(5-phospho-β-D-ribosyl)-ADP (PRADP), which could not be processed by HisIE. PRADP inhibited HisIE-catalyzed ProFAR formation from PRATP but not from PRAMP, suggesting that it binds to the phosphohydrolase active site while still permitting unobstructed access of PRAMP to the cyclohydrolase active site. The kinetics data are incompatible with a build-up of PRAMP in bulk solvent, indicating HisIE catalysis involves preferential channeling of PRAMP, albeit not via a protein tunnel.

Rate Response of Poly(Ethylene Terephthalate)-Hydrolases to Substrate Crystallinity: Basis for Understanding the Lag Phase.

The rate response of poly(ethylene terephthalate) (PET)-hydrolases to increased substrate crystallinity (XC ) of PET manifests as a rate-lowering effect that varies significantly for different enzymes. Herein, we report the influence of XC on the product release rate of six thermostable PET-hydrolases. All enzyme reactions displayed a distinctive lag phase until measurable product formation occurred. The duration of the lag phase increased with XC . The recently discovered PET-hydrolase PHL7 worked efficiently on "amorphous" PET disks (XC ≈10 %), but this enzyme was extremely sensitive to increased XC , whereas the enzymes LCCICCG , LCC, and DuraPETase had higher tolerance to increases in XC and had activity on PET disks having XC of 24.4 %. Microscopy revealed that the XC -tolerant hydrolases generated smooth and more uniform substrate surface erosion than PHL7 during reaction. Structural and molecular dynamics analysis of the PET-hydrolyzing enzymes disclosed that surface electrostatics and enzyme flexibility may account for the observed differences.

Engineering the Active Site Lid Dynamics to Improve the Catalytic Efficiency of Yeast Cytosine Deaminase

Conformational dynamics is important for enzyme catalysis. However, engineering dynamics to achieve a higher catalytic efficiency is still challenging. In this work, we develop a new strategy to improve the activity of yeast cytosine deaminase (yCD) by engineering its conformational dynamics. Specifically, we increase the dynamics of the yCD C-terminal helix, an active site lid that controls the product release. The C-terminal is extended by a dynamical single α-helix (SAH), which improves the product release rate by up to ~8-fold, and the overall catalytic rate kcat by up to ~2-fold. It is also shown that the kcat increase is due to the favorable activation entropy change. The NMR H/D exchange data indicate that the conformational dynamics of the transition state analog complex increases as the helix is extended, elucidating the origin of the enhanced catalytic entropy. This study highlights a novel dynamics engineering strategy that can accelerate the overall catalysis through the entropy-driven mechanism.

A co-kurtosis based dimensionality reduction method for combustion datasets

Principal Component Analysis (PCA) is a dimensionality reduction technique widely used to reduce the computational cost associated with numerical simulations of combustion phenomena. However, PCA, which transforms the thermo-chemical state space based on eigenvectors of co-variance of the data, could fail to capture information regarding important localized chemical dynamics, such as the formation of ignition kernels, appearing as extreme-valued samples in a dataset. In this paper, we propose an alternate dimensionality reduction procedure, co-kurtosis PCA (CoK-PCA), wherein the required principal vectors are computed from a high-order joint statistical moment, namely the co-kurtosis tensor, which may better identify directions in the state space that represent stiff dynamics. We first demonstrate the potential of the proposed CoK-PCA method using a synthetically generated dataset that is representative of typical combustion simulations. Thereafter, we characterize and contrast the accuracy of CoK-PCA against PCA for datasets representing spontaneous ignition of premixed ethylene-air in a simple homogeneous reactor and ethanol-fueled homogeneous charged compression ignition (HCCI) engine. Specifically, we compare the low-dimensional manifolds in terms of reconstruction errors of the original thermo-chemical state, and species production and heat release rates computed from the linearly reconstructed state. The latter – a comparison of species production and heat release rates – is a more rigorous assessment of the accuracy of dimensionality reduction. We find that, for the simplistic linear reconstruction, the co-kurtosis based reduced manifold represents the original thermo-chemical state more accurately than PCA, especially in the regions where chemical reactions are important.

Design and interpretation of experiments to establish enzyme pathway and define the role of conformational changes in enzyme specificity.

We describe the experimental methods and analysis to define the role of enzyme conformational changes in specificity based on published studies using DNA polymerases as an ideal model system. Rather than give details of how to perform transient-state and single-turnover kinetic experiments, we focus on the rationale of the experimental design and interpretation. We show how initial experiments to measure kcat and kcat/Km can accurately quantify specificity but do not define its underlying mechanistic basis. We describe methods to fluorescently label enzymes to monitor conformational changes and to correlate fluorescence signals with rapid-chemical-quench flow assays to define the steps in the pathway. Measurements of the rate of product release and of the kinetics of the reverse reaction complete the kinetic and thermodynamic description of the full reaction pathway. This analysis showed that the substrate-induced change in enzyme structure from an open to a closed state was much faster than rate-limiting chemical bond formation. However, because the reverse of the conformational change was much slower than chemistry, specificity is governed solely by the product of the binding constant for the initial weak substrate binding and the rate constant for the conformational change (kcat/Km=K1k2) so that the specificity constant does not include kcat. The enzyme conformational change leads to a closed complex in which the substrate is bound tightly and is committed to the forward reaction. In contrast, an incorrect substrate is bound weakly, and the rate of chemistry is slow, so the mismatch is released from the enzyme rapidly. Thus, the substrate-induced-fit is the major determinant of specificity. The methods outlined here should be applicable to other enzyme systems.

Demographics and host-kill parameters of Diglyphus horticola Khan against Chromatomyia horticola (Goureau).

The pea leafminer, Chromatomyia horticola (Goureau) (Diptera: Agromyzidae) is a polyphagous and serious pest of peas. In India, this pest is attacked by many parasitoids and among them Diglyphus horticola Khan (Hymenoptera: Eulophidae) is an important one, however, demographics and pest-kill potential of this parasitoid has not been studied so far. This study presents the first report on its demographics and pest-kill potential on C. horticola. The parasitoid showed three modes of host-killing behaviour viz. host-feeding, parasitism and host-stinging. The parasitoid females killed more number of hosts by parasitism than host-feeding or host-stinging. The pre-adult survival, net reproductive rate, intrinsic rate of increase (rm) and finite rate of increase (λ) were higher on the 5-days old host larvae than those reared on the 3-days old larvae. Demographics and pest-kill parameters of D. horticola were also better on 5-days old host larvae than on 3-days old host larvae. Based on the study, D. horticola appeared to be a promising biocontrol agent for the suppression of C. horticola in peas and could be promoted through conservation biological control. Further studies are required to standardize the mass production protocol and release rates to use the parasitoid by augmentation.

Introduction to Modelling the Correlation Between Grain Sizes of Feed Material and the Structure and Efficiency of the Process of Co-Rotating Twin-Screw Extrusion of Non-Flammable Composites with a Pla Matrix

Abstract Co-rotating twin-screw extrusion is an energy consuming process that is generally not fully optimised to a specific polymer. From the point of view of the efficiency of the extrusion process, the starting material should be characterised by small grain sizes in comparison to the screw channel area, small surface area to volume ratio and small internal friction between the pellets. To develop a model describing the effect of polylactide (PLA) grain size on the extrusion efficiency, a series of experiments with a twin-screw extruder were carried out during which the energy consumption; torque on shafts and temperature of the melt on the extruder die were monitored. As feed material, both the neat PLA with different grain sizes and the PLA with expandable graphite fillers and phosphorous-based flame retardants were used. Morphology and dispersion quality of the composites were examined using scanning electron microscopy (SEM); flammability, smoke production, mass loss and heat release rates were tested using cone calorimetry; and melt flow rate was determine using a plastometer. Moreover, the thermal properties of the obtained composites were determined using differential scanning calorimetry (DSC). The results show that the choice of the starting material affects both the efficiency of the extrusion process and the flame retardancy properties of the composite materials.

A sustainable green electron reactive processing for fire safety of polypropylene nanocomposites

In this work, a sustainable green electron reactive processing for fire safety of polypropylene (PP) nanocomposites was designed and developed. Effect of electron reactive processing on the morphology, fire safety and tensile properties of PP nanocomposites were characterized. The results showed that the smoke production and heat release rate of PP nanocomposites were reduced by electron reactive processing. Moreover, the total heat release and rating level of PP nanocomposite in UL-94 measurement were not reduced by electron reactive processing. Furthermore, the quality of carbon layer of PP nanocomposites via electron reactive processing in the condensed-phase was also discussed. The results suggest that electron reactive processing is a sustainable green way toward fire safety of polymer nanocomposites without any negative influence on tensile properties.

Smoke suppression and phosphorus-free condensed phase flame-retardant epoxy resin composites based on Salen-Ni

To avoid potential ecological and health problems caused by phosphorus-based flame retardants, a novel phosphorus-free PBA-Salen-Ni flame retardant is successfully synthesized in this work. In a nutshell, boron-containing metal complexes are prepared by nickel salts and chelating PBA-Salen molecule (PBA: p-phenylenediboronic acid). While the obtained material inherently has good compatibility and can endow polymers with good flame retardant properties at low addition levels. Besides, the char shielding layer and the “labyrinth effect” of the special porous char layer structure formed after the combustion of EP/PBA-Salen-Ni retard the transfer of volatile products, giving EP excellent smoke suppression properties. The results show that the limiting oxygen index value of the EP/PBA-Salen-Ni composites is increased from 25.6% (pure EP) to 30.5%, and it can pass the UL-94 V-0 rating when the addition amount is only 5wt%. Particularly, compared with pure EP, the total smoke production (19.9 m2) and peak heat release rate (859.6 kW m−2) of EP/PBA-Salen-Ni composites are reduced by 36% and 33%, respectively. Therefore, this work provides a new idea for the rational design of phosphorus-free flame retardants that are mainly on condensed phase flame retardancy and have a good smoke suppression effect.

Influence of substrate crystallinity and glass transition temperature on enzymatic degradation of polyethylene terephthalate (PET)

This work examines the significance of the degree of crystallinity (XC) of polyethylene terephthalate (PET) and the PET glass transition temperature (Tg) on enzymatic degradation of PET at elevated temperatures using two engineered, thermostable PET degrading enzymes: LCCICCG, a variant of the leaf-branch compost cutinase, and DuraPETase, evolved from the Ideonella sakaiensis PETase. The XC was systematically varied by thermal annealing of PET disks (Ø 6 mm, thickness 1 mm). The XC affected the enzymatic product release rate that essentially ceased at XC 22–27% for the LCCICCG and at XC ∼17% for the DuraPETase. Scanning Electron Microscopy revealed that enzymatic treatment produced cavities on the PET surface when the XC was > 10% but resulted in a smooth surface on amorphous PET (XC ∼10%). The Tg of amorphous PET disks decreased from 75 °C to 60 °C during 24 h pre-soaking in water at 65 °C, while the XC remained unchanged. Enzymatic reaction on pre-soaked disks at 68 °C, i.e. above the Tg, did not affect the enzymatic product release rate catalyzed by LCCICCG. These findings improve the understanding of enzymatic PET degradation and have implications for development of efficient enzymatic PET upcycling processes.

Genetic Incorporation of Selenotyrosine Significantly Improves Enzymatic Activity of Agrobacterium radiobacter Phosphotriesterase.

Tyrosine plays important roles in many enzymes. To facilitate enzyme design, mechanistic studies and minimize structural perturbation in the active site, here we report the genetic incorporation of a novel unnatural amino acid selenotyrosine (SeHF), which has single-atom replacement in comparison to tyrosine. The arPTE-(Agrobacterium radiobacter Phosphotriesterase) Tyr309SeHF mutant exhibits a significant 12-fold increase in kcat and 3.2-fold enhancement in kcat /KM at pH 7.0. Molecular dynamics simulations show that the SeHF309 mutation results in a conformational switch which opens up the product release pocket and increases the product release rate, thereby elevating the overall enzyme activity. Significant improvement of the catalytic efficiency at neutral pH by single unnatural amino acid (UAA) mutation broadens the application of this enzyme, and provides valuable insights to the mechanism. Our method represents a new approach for designing enzymes with enhanced activity.

Organophosphorus modified hollow bimetallic organic frameworks: Effective adsorption and catalytic charring of pyrolytic volatiles

Up to now, hollow metal organic frameworks (MOFs) usually possess a single metal element, and the size and shape of hollow structure cannot be reasonably tuned. In this work, novel organophosphorus modified hollow bimetallic organic frameworks (W-Zr-MOF-DOPO) are successful synthesized. Briefly, zirconium-based MOFs octahedron is first prepared according to a modified method, then hollow bimetallic MOFs are obtained by etching with WO42− under acidic condition, and organophosphorus is grafted onto it by the Kabachnik-Fields reaction. Inspiringly, the particle size of zirconium-based MOFs can be adjusted by the adding of acetic acid, thus acquiring hollow MOFs with controllable interior channels. The as obtained material is employed to reduce the fire risk of epoxy resin (EP), in which the hierarchical pores and metals can effectively facilitate the adsorption and catalytic charring of pyrolytic volatiles. Moreover, the P element of organophosphorus acts both in the condensed and gas phases, endowing EP with excellent thermal stability, fire retardancy and smoke suppression. The results indicate that the limiting oxygen index value of W-Zr-MOF-DOPO/EP composite increases from 24.6% (pure EP) to 32.2% and it can pass UL-94 V-0 rating when the additive amount is only 3 wt%. Especially, the total smoke production (14.5 m2) and peak heat release rate (403 kW m−2) of W-Zr-MOF-DOPO/EP composite decrease by up to 36% and 58%, respectively, compared with pure EP. Therefore, this work draws novel inspirations for the rational design of polymer composites with high fire retardancy and smoke suppression performance.

Enhancing the flame retardancy for castor oil-based rigid polyurethane foams via silica aerogel

Silica aerogel (SA) was successfully synthesized by sol-gel method under ambient pressure drying. The first and second type silica aerogel/castor oil-based flame retardant rigid polyurethane foam (SA/RPUF) composites were then fabricated via blending SA into the interior of RPUFs and coating SA onto the surface of RPUFs, respectively. Properties of the composites, including density, thermal conductivity, compressive strength, specific modulus, hydrophobicity, chemical component, morphology, thermal stability, limiting oxygen index (LOI), UL-94 tests, cone calorimetry (CC) testing, and char residues stability were characterized. The results showed RPUFs with larger cell size via coating SA onto their surface had cracking properties on the physical and flame retardancy, especially RPUF-4. Compared with neat RPUF, RPUF-4 obtained greatly improved properties with specific modulus an increment of 107.62%, the LOI value an increase of 50.76%, the first and second peak heat release rates with respective reduction of 52.43% and 40.78%, and respective 56.86% and 47.82% reduction in the first and second peak smoke production release rates. Thus, this study shows RPUFs with larger cell size via coating SA onto their surface have great potential for fire safety as building insulation materials.