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Highlights • Cellulose-based halogen-free flame retardant (HECPM) was successfully prepared. • The solid expanded and dense char residue of HECPM is higher than 43% at 600 °C. • LOI value of PP/30% HECPM reaches 29.5% and samples can pass UL-94 V-0 rating. • Synergistic flame-retarding effect of HECPM and expandable graphite (EG) was found. • Conjunct char-forming and flame-retardant effect mechanism was primarily proposed. Abstract In this paper, a mono-component, cellulose-based and intumescent halogen-free flame retardant (HECPM) was prepared by introducing phosphate groups and melamine groups onto the structure of cellulose. And the chemical structure and surface morphology of HECPM was confirmed by FTIR, EDS and SEM, respectively. The thermal degradation tests demonstrate HECPM possesses great expansion property during the inducement of heat and the char residue of HECPM is higher than 43% at 600 °C. Moreover, the synergistic effect of HECPM and EG in flame-retarding polypropylene (PP) was also verified. When 30% HECPM/EG in ratio of 1/3 were introduced into PP, the LOI value reaches 31.5% and it can obtain UL-94 V-0 rating. The conjunct action of HECPM and EG in promoting the char-forming process was also achieved in comparison with the calculated and experimental TGA curves. Along with the investigation on the residue, a potential condensed-phase flame retardant mechanism was primarily proposed. [ABSTRACT FROM AUTHOR]

In this article, co-microencapsulation technology was utilized for decorating the surface of dialdehyde starch (DAS) and melamine polyphosphate (MPP) via one-step process. The aim for this design was to improve the dispersion for DAS and MPP in polypropylene (PP) and employ DAS as sustainable char-forming agent, which lied in enhancing the flame retardancy of PP. In view of chemical composition, morphology and surface wettability, the changes for DAS and MPP after modification were confirmed by energy dispersive spectrometer (EDS), scanning electron microscope (SEM) and water contact angle (WCA) tests, respectively. Most of all, the results for flame retardant tests demonstrated limiting oxygen index (LOI) value and vertical burning tests (UL-94) rating of PP/30 ph M[M&D] were 28.2% and V-1. Along with the synergistic effect, the homogeneous dispersion of DAS and MPP in PP after co-microencapsulation modification was also one of main reasons for the increased flame retardant properties. Except that, the chemical interaction between DAS and MPP in producing the char layer was also certified by TGA curves. After systematic analysis on char residue, the possible intumescent flame retardant mechanism was primarily proposed. • Dialdehyde starch (DAS) was utilized as renewable biomass-based char source. • Co-microencapsulated intumescent flame retardant system is established. • LOI value and UL-94 rating of PP/30 ph M[M&A] 1-1 are 28.2% and V-1. • Chemical interaction of flame retardants for producing char layer was confirmed. • Possible intumescent flame retardant mechanism was primarily proposed. [ABSTRACT FROM AUTHOR]

Nowadays, steel is one of the most significant materials in industry and daily life. Unfortunately, the defects of steel structures such as collapse at high temperature, poor corrosion resistance, and bad surface functionality have severely restricted their further application. Applying functional coatings for steel structures is considered the effective strategy for settling theses disadvantages. Inspired by nature, eco-friendly, superhydrophobic, and multifunctional-integrated coatings were fabricated on steel via one-step spraying strategy in this paper. Along with silicon dioxide (SiO 2) nanoparticles and epoxy resin/silicone resin (EP/SR), the coatings are jointly constituted by hydrophobic flame retardants (M-ALHP@ZIF-8) prepared via multi-stage modification. Due to the formation of micro/nano-scaled rough structure with low surface energy, the water contact angle (WCA) and water sliding angle (WSA) of as-prepared coatings can reach 162.4° ± 1.2° and 2.8° ± 0.4°. The water repellency with low water adhesion can endow the surface of steel with excellent self-cleaning, anti-fouling, and long-lasting anti-corrosion ability. Additionally, the superhydrophobic coatings have displayed good mechanical robustness, chemical stability and weather resistance, which can exhibit certain actual values. Accorded with Zn-catalyzed charring effect of flame retardants, as-prepared coatings have possessed outstanding fire protection capacity with the lowest backside temperature of 181 °C after 1 h fire impact tests. Consequently, this work has provided a facile and effective route for synchronously tackling the key challenges of poor fire protection and surface functionality for steel structures, which will be expected to pave the wide pathway for constructing multifunctional coatings in more fields. [Display omitted] • (1)Hydrophobic ZIF-8 doped aluminum hypophosphite has been fabricated. • Superhydrophobic and multi-functional composite coatings have been constructed on steel. • As-prepared coatings have exhibited good robustness, durability and adaptability. • The coatings are endowed with excellent self-cleaning, anti-corrosion and fire resistance. [ABSTRACT FROM AUTHOR]

Originated from the future trends and requirements for silicone rubber (SR) in harsh work condition of advanced cutting-edge fields (construction, aerospace, marine equipment and automobile, etc), the processing complexity, complex ingredients and unbalanced overall properties of traditional multi-component flame-retarding SR system are limited. The development of mono-component and halogen-free flame retardants with adequate efficiency, durability and strength have been urgently expected for settling the crucial bottleneck issue of SR materials, which can avoid the defects of performance contradictions for long-used multi-component system in previous published work. Under such background, this paper has fabricated a hydrophobic Mn-doped melamine phosphate (H-DTMA@Mn) via facile multi-stage construction strategy that has been confirmed by a series of characterizations. The results have indicated that SR/28 phr H-DTMA@Mn can achieve limiting oxygen index (LOI) of 32.4% and UL-94 V-0 rating. Along with the reduced peak heat release rate, the validity of as-prepared H-DTMA@Mn for raising the flame retardancy of SR has been straightway clarified. Different from the previous work, the prominent flame retardant durability of SR/H-DTMA@Mn in many extreme environment can be maintained via the protection action of hydrophobic structure. The detailed analysis on char residues of SR composites can explain the effective flame retardant mechanism in view of chemical composition and microscopic morphology. Moreover, the mechanical strength and thermal properties of SR composites are ideal and accommodated that are greatly required in the real-life application. To sum up, the desirable balance for comprehensive performance can be realized by introducing the mono-component flame retardants, which can innately open up the innovation for meeting the requirements of SR materials in more fields. • Mono-component and Mn-doped flame retardants were fabricated for SR. • SR/28 phr H-DTMA@Mn can gain 32.4% LOI value and UL‐94 V‐0 rating. • PHRR and THR reduction of SR/28 phr H-DTMA@Mn are 42.3% and 34.7%. • Excellent balance among comprehensive properties of SR composites can be achieved. • Multi-channel synergistic flame retardant mechanism is preliminarily deduced. [ABSTRACT FROM AUTHOR]

• A eco-friendly and effective flame retardant was obtained. • LOI and UL-94 rating of SR composites under 5% loadings reach 36.4% and V-0. • Hydrophobic modification can greatly improve the water resistance of SR. • Mechanical properties of SR composites are also enhanced. • This work provides a new choice for fabricating SR-based building materials. To address the bottleneck problem for flame-retarding silicone rubber (SR) in poor water resistance and low efficiency, a halogen-free and synergistic system was fabricated by the introduction of hydrophobic melamine polyphosphate (MPP) modified by layered double hydroxide (P-MPP@LDH) and expandable graphite (EG) in this paper. Dramatically, the limited oxygen index (LOI) of composites (SR/P-MPP@LDH 2.5 /EG 2.5) can reach as high as 36.4 % with UL-94V-0 rating when the total flame retardant loadings is only 5 phr, revealing the superior efficiency of novel system. Compared with neat SR, the fire risk of SR composites is observably decreased by conducting cone calorimeter tests. Significantly, bio-inspired hydrophobic modification is feasible for the excellent balance in simultaneously improving the flame retardancy, water resistance, and mechanical properties of SR in one system. Based on the analysis for residue and thermal degradation process, the effective flame retardant mechanism for SR composites can be attributed to the joint effect of LDH-catalyzed char-formation and physicochemical synergistic intumescence barrier. Therefore, this paper has provided a new and effective strategy to achieve the goal of flame retardancy with high performance in SR, which offers a new choice for designing and applying rubber composite materials in buildings. [ABSTRACT FROM AUTHOR]