抗氧化性可膨胀石墨的制备及其阻燃性能  

Preparation and flame retardancy of anti-oxidation expandable graphite

作　　者：庞秀言[1] 宋明凯[1] 翟志晓 

机构地区：[1]河北大学化学与环境科学学院,河北保定071002

出　　处：《河北大学学报（自然科学版）》2014年第2期166-173,共8页Journal of Hebei University(Natural Science Edition)

基　　金：河北省教育厅博士基金(B2004402)

摘　　要：建立了一种抗氧化性可膨胀石墨的制备方法.采用正交实验及单因素实验确定了可膨胀石墨的适宜制备条件:天然石墨C与KMnO4、质量分数98%H2SO4及Na4P2O7的质量比为1.0∶0.20∶5.0∶0.60,反应前硫酸用去离子水稀释至70%(质量分数),在40℃下反应40min,得普通可膨胀石墨(EG1);将EG1用去离子水洗涤脱色后,再用一定浓度的蔗糖硼酸脂镁溶液浸渍,经过脱水、60~80℃下干燥后得起始膨胀温度165℃、膨胀容积400mL/g的抗氧化性可膨胀石墨(EG).通过氧指数测定、热重和差热分析等手段考察了该EG对线性低密度聚乙烯(LLDPE)的阻燃性能.结果表明:添加未经蔗糖硼酸脂镁处理的EG1为阻燃剂使LLDPE氧指数提高到26.1%;添加30%(质量分数)EG可以使LLDPE的氧指数提高到29.8%,而残炭量可由18.6%提高至23.4%,说明在高温下EG可形成高热稳定性炭层,从而实现良好的阻燃性能.进一步分析了LLDPE/EG/APP(Ⅰ)(聚磷酸铵)体系可能的阻燃机理,并考察了阻燃剂的加入对LLDPE的拉伸强度的影响.Expandable graphite is easily oxidized under high temperature, and it normally possesses low residual char using as flame retardant. A method to prepare graphite intercalating compound with a high anti-oxidation was studied. Feasible experiment conditions were investigated through orthogonal tests and single factor experiments. Expandable graphite could be prepared according to the following mass rati- o： natural graphite C ： Na4P207 ＂ H2SO4 （mass concentration 98~） ＂ KMnO4 equals 1.0 ＂ 0.20 ： 5.0 ＂ 0.60, H^SO4 with a mass concentration of 98% should be diluted to 70% with deionized water before in- tercalation reaction）, and reaction lasted 40 rain at 40 ℃. After washing to discolor, the normal expand- able graphite （EG1） was obtained. The EG1 was subsequently macerated in cane sugar borate magnesium. After dehydration and drying at 60 - 80 ℃, anti-oxidation expandable graphite （EG） with an initiation expansion temperature and expansion volume of 165 ℃, 400 mL/g was prepared. We characterized the flame retardancy of EG for LLDPE by limiting oxygen index LOI, Thermal gravimetric TG and differential thermal analysis DTA. Addition of 30% of the EG1 （mass ratio） to LLDPE could improve LOI to 26.1% from 17.7%, and the residual char was 18.6%; while addition of 30% of the EG improved the LOI to 29.8%, and the residual char was 23.4%. Under high temperature, EG could form more stable char layer on material surface than the EG1, and it ensured the well flame retardancy for LLDPE. Possible anti-flame mechanism of the LLDPE/EG/APP （I） was discussed and the influence EG and APP （ I ） on LLDPE ten- sile strength was detected.

关 键 词：抗氧化性可膨胀石墨 线性低密度聚乙烯 膨胀性能 氧指数 蔗糖硼酸脂镁 残炭量 

分 类 号：O635.1[理学—高分子化学]