Category Ranking

98%

Total Visits

921

Avg Visit Duration

2 minutes

Citations

20

Article Abstract

Surface cracking is a major issue in amino resin-based flame-retardant coatings, which can be reduced by mixing flexible resins into the coatings. In this study, flexible waterborne polyurethane (WPU) was added into a melamine-modified, urea-formaldehyde, resin-based intumescent flame retardant (MUF-IFR) coating. A molecular chain of WPU was inserted into the MUF network and formed a WPU/MUF-semi-IPN structure. The cracking resistance of the coating was gradually enhanced with the increase in WPU content. When the WPU content exceeded 25% of the total resin, there were no cracks in the coatings after crack-resistance tests. The coatings before and after toughening showed good transparency on wood surfaces. The influence of WPU on char formation and flame retardant properties were explored by TGA, SEM, and cone calorimetry. The results showed that the decomposition of WPU occurred before char formation, which decreased the integrity of the coating and damaged the compactness of the char. Therefore, the addition of WPU reduced the expansion height and the barrier capacity of the char as well as the flame retardant properties of the coating. When the amount of WPU was 25% of the total resin, compared to the non-WPU coating, the average heat release rate in 300 s (AveHRR) and the total heat release at 300 s (THR) of the samples were increased by 45.8% and 35.7%, respectively. However, compared to the naked wood, the peak heat release rate (pHRR), AveHRR, and THR of the samples with the coating containing 25% WPU were decreased by 64.2%, 39.0%, and 39.7%, respectively. Therefore, the thermal stability of WPU affected char formation. The amount of WPU added should be chosen to be the amount that was added just before the coating cracked.

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9231142PMC
http://dx.doi.org/10.3390/ma15124122DOI Listing

Publication Analysis

Top Keywords

flame retardant
12
char formation
12
heat release
12
wpu
11
flame-retardant coatings
8
waterborne polyurethane
8
wpu content
8
25% total
8
total resin
8
wpu char
8

Similar Publications

To analyse the issues of high muzzle flame intensity and the easy migration of insensitive agents in conventional insensitive propellants, this study synthesizes modified nitrocellulose grafted with carboxymethyl potassium groups by a two-step process, starting from the molecular structure of nitrocellulose (NC), the principal component of propellants. First, the denitration reaction was performed to reduce part of the nitrate ester groups on the surface of NC to hydroxyl groups, followed by an etherification reaction to achieve directional grafting of carboxymethyl potassium groups. Compared with conventional flame retardant/insensitive systems based on nitrogen, phosphorus, or DBP (dibutyl phthalate), potassium-based functional groups exhibit superior thermal stability and environmental friendliness.

View Article and Find Full Text PDF

In the zebrafish larval toxicity model, phenotypic changes induced by chemical exposure can potentially be explained and predicted by the analysis of gene expression changes at sub-phenotypic concentrations. The increase in knowledge of gene pathway-specific effects arising from the zebrafish transcriptomic model has the potential to enhance the role of the larval zebrafish as a component of Integrated Approaches to Testing and Assessment (IATA). In this paper, we compared the transcriptomic responses of triphenyl phosphate between two standard exposure paradigms, the Zebrafish Embryo Toxicity (ZET) and General and Behavioural Toxicity (GBT) assays.

View Article and Find Full Text PDF

Pollution can have lasting effects beyond the exposure period, potentially impacting multiple generations. Polybrominated diphenyl ether (PBDE) flame retardants are widespread, including in oceans, yet their multigenerational impacts remain poorly understood. We investigated whether BDE-99, a ubiquitous PBDE, induces neurobehavioral and molecular effects across generations in the fish .

View Article and Find Full Text PDF

Tetrabromobisphenol A (TBBPA), a widely used flame retardant in textiles and electronics, poses toxicological risks through both environmental and indoor exposures. Biomonitoring studies have detected significant TBBPA levels in prenatal environments, including cord blood, raising concerns about developmental impacts. Using zebrafish as a model, this study addresses critical gaps in understanding how developmental TBBPA exposures perturb regulatory pathways that govern dorsoventral patterning.

View Article and Find Full Text PDF

Dual Lithium Salt Derived Favorable Interface Layer Enables High-Performance Polycarbonate-Based Composite Electrolytes for Stable and Safe Solid Lithium Metal Batteries.

ACS Appl Mater Interfaces

September 2025

Ministry of Education Key Laboratory for the Green Preparation and Application of Functional Materials, Hubei Key Laboratory of Polymer Materials, School of Materials Science and Engineering, Hubei University, Wuhan 430062, China.

Developing solid electrolytes with high ionic conductivity, a high voltage window, low flammability, and excellent interface compatibilities with both the anode and cathode for lithium-metal batteries is still a great challenge but highly desirable. Herein, we achieve this target through an in situ copolymerization of vinyl ethylene carbonate (VEC) together with acrylonitrile (AN) under fitting ratios inside a porous polyacrylonitrile (PAN) fiber membrane doped with flame-retardant decabromodiphenyl ethane (DBDPE) molecules. The received fiber-reinforced polycarbonate-based composite electrolyte with an ultrathin thickness of 13 μm exhibits good internal interfacial compatibility because of the same AN structure and superior flame-retardant performance due to the doped DBDPE molecules.

View Article and Find Full Text PDF