Polymerization of (o‐methylphenyl)acetylene and polymer characterization

Abstract

(o‐Methylphenyl)acetylene polymerized with high yields in the presence of W and Mo catalysts. W catalysts were more active than the corresponding Mo catalysts. The weight‐average molecular weight of the polymer formed with W(CO)6–CCl4–hv reached 8 × 105, being higher than the maximum value (ca. 2 × 105) for poly(phenylacetylene). The polymer had the structure \documentclass{article}\pagestyle{empty}\begin{document}$\rlap{--} [{\rm CH} \hbox{=\hskip-1pt=} {\rm C}(o - {\rm CH}_3 {\rm C}_6 {\rm H}_4 )\rlap{--} ]_n $\end{document}. The stereochemical structure of the main chain could be determined by 13C‐NMR; the cis content varied in a range of 41–61% depending on the polymerization conditions. The present polymer was thermally more stable than poly(phenylacetylene) according to thermogravimetric analysis. Interestingly, this polymer possessed deeper color than poly(phenylacetylene), and showed a fairly strong absorption in the visible region.

Polymerization of (o-Alkylphenyl)acetylenes and Polymer Properties

“…All the three W catalysts in the table polymerize this monomer in over 65% yields. The polymers obtained with WCl6-Ph4Sn and W(CO) 6 -hv possess Mw's around 2 x 10 5 . MoCl 5 and its mixture with Ph4Sn also form poly(o-iso-PrPA)s quantitat- In order to gain knowledge on the relative reactivity of ortho-substituted monomers, their copolymerizations with phenylacetylene were carried out in toluene at 30°C;…”

“…1 • 5 W(C0) 6 -hv catalyst) and good thermal stability. 6 It has recently been found that phenylacetylenes with even bulkier ortho groups (e.g., CF 3 7 and Me 3 Si 8 • 9 ) yield polymers with very high molecular weight (Mw 1 x 10 6 and above).…”

“…1 • 5 W(C0) 6 -hv catalyst) and good thermal stability. 6 It has recently been found that phenylacetylenes with even bulkier ortho groups (e.g., CF 3 7 and Me 3 Si 8 • 9 ) yield polymers with very high molecular weight (Mw 1 x 10 6 and above).Thus it is interesting to examine how high the molecular weight of the polymer becomes when a substituent is introduced onto the ortho position of phenylacetylene to increase steric crowding. In fact, we studied the polymerization of(o-methylphenyl)acetylene (o-MePA) to find the formation of a polymer having high molecular weight (Mw up to 8 x 10 5 with * To whom correspondence should be addressed.…”

“…However, both o-EtPA (bp 61 °C/12.5 mmHg), which is difficult to perfectly separate from phenylacetylene by simple distillation, and o-iso-PrPA (bp 54°Cjl0 mmHg), for which the foregoing process is not applicable because of difficulty in the alkylation reaction, were prepared from 2-methyl-3-208 butyn-2-ol and l-alkyl-2-iodobenzenes by the same method as for (o-methylphenyl)acetylene. 6 Transition-metal chlorides and organometallic cocatalysts were commercially obtained, and used without further purification. Toluene, CC1 4 etc.…”

Investigations on homopolymerization and copolymerization of phenylacetylene and 1‐hexyne by iron‐based ziegler‐natta catalyst systems

“…By processing composition data (Tab.2) according to the KT equation (6) and NLLSprocedure, the FA-and r~~-v a l u e s were calculated. The results obtained are compiled in Tab.3.…”