聚双酚酸苯基磷酸酯的合成及其与APP协同阻燃EVA的研究

摘要：采用来源于生物质资源的双酚酸为原料,利用界面聚合法合成新型阻燃剂聚双酚酸苯基磷酸酯(poly(DPA PDCP)).探索了时间、催化剂用量、氢氧化钠用量等因素对其产率的影响,在优化的工艺条件下（室温、催化剂摩尔分数为0.04,nNaOH∶nDPA=3,反应时间为0.5 h）,poly(DPA PDCP)产率可达75%.当poly(DPA PDCP)与APP以1∶4比例复配阻燃EVA,总添加量质量分数为30%时,EVA的氧指数达到25.7%;锥形量热测试表明最大热释放速率降低61%;TGA测试显示起始分解温度较纯EVA提高32 ℃,最大分解温度提高20 ℃,同时在600 ℃的残炭量质量分数高达27%.结果表明,poly(DPA PDCP)与APP复配阻燃体系主要以固相阻燃机理为主;poly(DPA PDCP)主要作为碳源,与APP配合使用时存在协同阻燃效应.     

Synergistic effects of 4A zeolite on the flame retardant properties and thermal stability of a novel halogen‐free PP/IFR composite

The synergistic effects of 4A zeolite (4A) on the thermal degradation, flame retardancy and char formation of a novel halogen‐free intumescent flame retardant polypropylene composites (PP/IFR) were investigated by the means of limiting oxygen index (LOI), vertical burning test (UL‐94), digital photos, scanning electron microscopy (SEM), thermogravimetric analysis (TGA), cone calorimeter test (CCT), laser Raman spectroscopy (LRS) and X‐ray photoelectron spectroscopy (XPS). It was found that a small amount of 4A could dramatically enhance the LOI value of the PP/IFR systems and the materials could pass the UL‐94 V‐0 rating test. Also, it could enhance the fire retardant performance with a great reduction in combustion parameters of PP/IFR system from CCT test. The morphological structures observed by digital and SEM photos revealed that 4A could promote PP/IFR to form more continuous and compact intumescent char layer. The LRS measurement, XPS and TGA analysis demonstrated that the compactness and strength of the outer char surface of the PP/IFR/4A system was enhanced, and more graphite structure was formed to remain more char residue and increase the crosslinking degree. Copyright © 2013 John Wiley & Sons, Ltd.     

Thermal properties and combustion behaviors of UV‐cured phosphate triacrylate/star poly(urethane acrylate) oligomer blends

A series of UV‐curable intumescent flame retardant resins was obtained by blending phosphate triacrylate (TAEP) in certain ratios with star poly(urethane acrylate) (SPUA) oligomer. The flammability of the cured films was characterized by limited oxygen index (LOI), UL 94, and the cone calorimeter. The results showed that the cured TAEP/SPUA samples greatly expanded while burning. A distinct synergistic effect was found between TAEP and SPUA. TAEP2 sample showed the highest LOI value (41) among all resins. The cone calorimeter results showed that the peak heat release rates and carbon monoxide yield decreased to the approximate level. The degradation was monitored by thermogravimetric analysis and real‐time Fourier transform infrared spectroscopy. A degradation mechanism is suggested in which the phosphate group in TAEP first degraded to form poly(phosphoric acid)s, which further catalyzed the degradation of the material to form char with emission of carbon dioxide and nitrogen volatiles from SPUA, leading to the formation of expanding char. The morphologic structures of crusts of the formed chars were observed by scanning electron microscopy, demonstrating the synergistic effect between TAEP and SPUA. Copyright © 2008 John Wiley & Sons, Ltd.