双氰胺改性酚醛泡沫塑料性能研究

Study on Properties of Phenolic Foam Plastics Modified by Dicyandiamide

针对酚醛泡沫塑料脆性大和强度低的缺点,采用双氰胺作为改性剂,对酚醛树脂及其泡沫塑料进行了改性研究,并将改性前后两种泡沫塑料的性能进行了对比。采用傅立叶变换红外光谱对酚醛树脂进行了结构表征,通过粉化率、冲击强度和压缩强度测试分析了改性酚醛泡沫塑料的脆性和力学性能,通过热失重分析了改性酚醛泡沫塑料的热稳定性,并采用极限氧指数仪测定了改性酚醛泡沫塑料的阻燃性能。结果显示,当加入的双氰胺用量为苯酚质量的3%时,改性酚醛泡沫塑料的综合性能最好,其压缩强度达到0.046 MPa,冲击强度达到3.36 k J/m2,粉化率低至2.13%,极限氧指数达到38.5%。相对于纯酚醛泡沫塑料,双氰胺改性酚醛泡沫塑料的力学性能有所提升,脆性明显改善。在热稳定性方面,纯酚醛泡沫塑料在340℃时已明显失重,而3%双氰胺改性酚醛泡沫塑料在370℃后才开始快速失重,热稳定性更好。随着双氰胺用量的增加,改性酚醛泡沫塑料的极限氧指数增大,阻燃性能有所提高。

For the brittleness and low strength of phenolic foam plastics, dicyandianmide （DICY） as modltylng agent was 1 adopted to prepare phenolic resin and phenolic foam plastics. The performances of the modified phenolic foam plastics were compared with the unmodified phenolic foam plastics. The Fourier transformation infrared spectroscopy was used to test the structures of the phenolic resins, the brittleness and mechanical properties of the phenolic foam plastics were tested by pulverization rate, impact strength and compressive strength, the thermogravimetic analysis was used to test the thermostability, and the limited oxygen index was tested to show the flame retardant properties of the phenolic foam plastics. The results show that the modified phenolic foam plastic has the best performance when DICY content is 3% of phenol mass, the compressive strength is 0.046 MPa, the impact strength is 3.36 kJ/m^2, the pulverization rate is 2.13% and the limited oxygen index is 38.5%, which are improved dramatically compared with the pure phenolic foam plastic. The thermogravimetic analysis shows that the pure phenolic foam plastic has obvious weightlessness at 340℃, however, the phenolic foam plastic modified by 3% DICY begins to loss weight obviously after 370 ℃, which means better therrnostability. As the addition of DICY, the limited oxygen index is increased, the flame retardant properties of modified phenolic foam plastics are improved.