The Biodegradable Polymer Thz Spectroscopy Study

In recent years,with the increasing "White Pollution" caused by chemosynthetic polymers people pay their attentions to the research of bio-degradable polymers.The optical characteristics of 2 kinds of elementary polymers and 4 kinds of bio-degradable polymers are detected by THz-TDS,which include Polyethylene Polyethylene oxide Poly-3-hydroxybutyrate Poly-(3-hydroxybutyrate-co-hydroxyvalerate) Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) and Poly-L-Lactide.The refractive indices and the dispersion coefficients of those samples are obtained based on the physical model represented by T.D.Dorney and L.D.Duvillaret to abstract the optical parameters of materials in range between 0.2 and 2.6THz.The absorption peaks have the significant difference between the different samples.Comparing the spectrums of absorption and refractive indes of the same sample,the relationship between absorption and dispersion is discussed.When closing to the absorption peak,the refractive index decreases as the increasing of the frequency,and when far away the absorption peak,the refractive index increases as the increasing of the frequency.The characteristic absorption peaks of samples are assigned to their monomer functional groups,according to their monomer structure.In succession,the IR spectrums of PHB PHBV and PHBHHx are detected.Comparing the spectrums of IR and THz, it was found that the two kinds of spectroscopy are consistent in revealing the molecular vibrational mode.This article research results provides the essential data and the new method for using THz-TDS to study the conformation and molecular dynamic of bio-degradable polymer.