反射光谱法测定交联聚苯乙烯的复折射率

交联聚苯乙烯是一种热固性塑料，具有优异的介电特性和耐高压击穿能力等特性，在微波窗口、电子工程、国防军工等方面具有很大的潜在应用价值，而其在红外波段的光学特性却鲜有研究。文中用射线辐照聚合法制备了新型交联聚苯乙烯样品，采用傅里叶变换红外光谱（Fourier Transform Infrared Spectroscopy）技术，测量了交联聚苯乙烯和聚苯乙烯在红外波段的反射光谱，进而利用Kramers-Kronig（K-K）关系导出了复折射率，并对计算结果进行了误差分析。结果表明:交联聚苯乙烯的折射率在太赫兹波段与聚苯乙烯相近，随着频率升高迅速下降，在中红外波段稳定在1.1~1.2之间，远低于聚苯乙烯的折射率（1.5左右）。

Measurement of complex refractive index of cross-linked polystyrene by reflection spectra

Cross-linked polystyrene is a kind of thermosetting plastic which has excellent dielectric properties and high breakdown voltage. It has great potential application value in microwave window, electrical engineering and military industry, while the infrared optical property of cross-linked polystyrene was rarely studied. A new cross-linked polystyrene sample was prepared by a novel method of -ray radiation polymerization in this paper. Cross-linked polystyrene and polystyrene were analyzed by Fourier transform infrared spectroscopy(FTIR), and the reflective spectra were measured. Subsequent Kramers-Kronig(K-K) analysis provided the dispersion of complex refractive index across the measured region, and calculation errors were analyzed. The results show that the refractive index of cross-linked polystyrene is similar to that of polystyrene in terahertz frequency, and in infrared region decreased rapidly with respect to the frequency(about 1.1-1.2 in mid-infrared region), which is much lower than that of polystyrene (around 1.5).