The structures of two 4-methyl-l-pentene copolymers with 1,5-hexadiene prepared with a Ziegler catalyst system have been studied by 13C nuclear magnetic resonance spectroscopy. The copolymers have been found to have two repeat units, i.e. 4-methyl-l-pentene (A) and 1-methylene-3-cyclopentyl (B) units. The introduction of the rigid cyclic unit into the 4-methyl-1-pentene sequences brings about significant changes in the structure and properties. The resulting two copolymers, which are composed of A and B units in the ratios 83/17 and 57/43, form ordered molecular aggregates in the amorphous states as confirmed by X-ray diffraction patterns. This result is in contrast to the well known fact that 4-methyl-1-pentene copolymer with 20 mol% of 1-hexene has a crystallinity of about 50%.
Посилання на статтю:
A study of the structure and crystallinity of 4-methyl-1-pentene copolymers with 1,5-hexadiene by zac nuclear magnetic resonance and X-ray diffraction methods / Akira Mizuno*, Jun-ichi Yoshitake, Takeshi Muranakat,Hiroaki Kitani and Norio Kashiwa // Polymer. – 1992. – Vol 33. – P. 259-263.