Synthesis And Property Research Of Polyacetonitrile

The polymer with a Π electron conjugated backbone has broad application value in photoelectric materials, semiconductor materials, magnetic elements, catalysts and radiation resistance etc. The nitrile polymer is always considered to be the most promising conductive polymer among the conjugated polymer materials, and the polyacetonitrile is a typical nitrile polymer material. The polyacetonitrile owns high specific surface area, good heat resistance and superior semiconductor performance, which has wide application prospect in the fields of transistors, chemical sensors, microelectronics components, circuit design and antistatic materials etc. In addition, acetonitrile is a by-product(about 2-3%) of production acrylonitrile by propylene ammonia oxidation process, and the annual output is huge. However, the present acetonitrile is mainly used as organic solvent, which is uneconomical. Moreover, the acetonitrile is an important intermediate in organic synthesis. The additional value of acetonitrile can be greatly improved through polymerizing acetonitrile to polyacetonitrile. Therefore, it is significantly important to research polymerization of acetonitrile to polyacetonitrile.In this paper, the acetonitrile was used as a raw material, which formed complex with the friedel-crafts catalysts(zinc chloride, titanium chloride, cobalt dichloride and boron trifluoride) respectively. And then a linear polyacetonitrile was formed at a definite temperature. The polymerization temperature, polymerization time, the kind of initiator and the ratio of raw materials were investigated. The polyacetonitrile material properties, polymerization kinetics and reaction mechanism were researched. The results showed that zinc chloride has the best catalytic performance on this polymerization process, and the best polymerization conditions was: sodium methoxide as the initiator, the ratio of CH3CN/Zn Cl2 at 1:0.5, under 200 ℃and reaction 6 hours. Under this reaction condition, the polymerization conversion of acetonitrile is 80.2%, and the molecular weight of the obtained polyacetonitrile is more than 50000. The as-perpared polyacetonitrile shows good thermal stability, semiconductive performance and microwave absorption capability, so it is expected to great application value in the field of semiconductor materials and low frequency microwave absorption.