The Fundamental Properties and Thermal Decomposition Characteristics of Poly-4-methylpentene-1

The fundamental properties and thermal decomposition characteristics of poly-4-methylpentene-1 were investigated. The results are as follows: (1) This polymer consists mainly of an 1, 2-polymer structure. (2) Its molecular weight decreases more than 20% after being made into films. (3) The crystalline melting point of its copolymer becomes about 5°C lower and the crystallinity becomes 6% smaller than those of its homopolymer. (4) Its dynamic visco-elasticity characteristics resemble its dielectric dispersion characteristics. Its dielectric constant is the smallest among all high polymer dielectrics. Its tan δ characteristics show the biggest peak value at room temperature. (5) This polymer evolves isobutene, propane, 4-methyl-1-pentene, etc. as incipient thermal decomposition products. The decomposition mechanism was well interpreted by the intramolecular radical transfer process which is common in the random decomposition of polyolefins.