Copolymerization of ethene with methyl acrylate and ethyl 10-undecenoate using a cationic palladium diimine catalyst

The cationic palladium catalyst [(ArN=C(Me)C(Me)N=Ar)Pd(CH3)(NC-CH3)]+BAr'( -)(4) (Ar = 2.6-C6H3(CH(CH3)(2)): Ar' = 3.5-C6H3(CF3)(2)) (DMPN/borate) was applied in ethene homopolymerization as well as ethene copolymerization wi th polar monomers such as methyl acrylate and ethyl 10-undecenoate. Both et hene homo- and copolymerization afforded amorphous, branched polyethenes wi th glass temperatures around -65 degrees C and very similar high degree of branching (105 branched C/1000C), which was independent of temperature and ethene pressure. Copolymerization with pc,lar comonomers gave polyethylene containing both alkyl and ester-functional alkyl side chains. The ratio of both types of short chain branches was influenced by the feed concentration of pr,lar monomer. In the presence of sterically hindered phenols (e.g., 2 ,6-di-tert-butyl-4-methylphenol (BHT)) and tetramethylpiperidine-N-oxyl rad ical (TEMPO) acrylate homopolymerization was prevented. BHT addition promot ed both catalyst activity and methyl acrylate incorporation significantly. Polymerization reaction, polymer microstructures and polymer properties of polar and nonpolar branched polyethenes were investigated.