Fraction of 83 Conversion to 85 / % PDi Tg / °C a mixture of and (in 10 83) 0.25 21 1.31 166 0.33 25 1.34 176 0.50 24 1.43 180 0.67 15 1.34 184 0.75 15 1.40 190 Scheme 49: The co-polymerisation of styrene (10) and (83) by N-cyclohexylmaleimide ATRP, to produce co-polymers with a low PDi. As shown in Scheme 49, ATRP can be used for the co-polymerisation of styrene (10) and (83) to produce the polymeric species (85) with a low PDi. Also N-cyclohexylmaleimide in this work, it was shown that increasing the fraction of (83) from N-cyclohexylmaleimide 0.25 to 0.75 resulted in an increase in the Tg (166 - 190 °C) of the co-polymer (85); this is attributed to the higher proportion of the rigid 5-membered maleimide structure in the final polymer, which has a higher thermal stability than the more flexible styrene. Nitroxide mediated co-polymerisation of maleimides with styrene (10) can also be used to control the molecular weight distribution of maleimide polymers. For example, Lokaj and co-workers have shown that heating maleimide (86) and styrene (10) with TEMPO (15) can lead to a maleimide-styrene co-polymer with a low PDi and good thermal stability (87) (Scheme 50).99
Fraction of 83 (in a mixture of 10 and 83) Conversion to 85 / % PDi Tg / °C 0.25 21 1.31 166 0.33 25 1.34 176 0.50 24 1.43 180 0.67 15 1.34 184 0.75 15 1.40 190 Scheme 49: The co-polymerisation of styrene (10) and N-cyclohexylmaleimide (83) by ATRP, to produce co-polymers with a low PDi. As shown in Scheme 49, ATRP can be used for the co-polymerisation of styrene (10) and N-cyclohexylmaleimide (83) to produce the polymeric species (85) with a low PDi. Also in this work, it was shown that increasing the fraction of N-cyclohexylmaleimide (83) from 0.25 to 0.75 resulted in an increase in the Tg (166 - 190 °C) of the co-polymer (85); this is attributed to the higher proportion of the rigid 5-membered maleimide structure in the final polymer, which has a higher thermal stability than the more flexible styrene. Nitroxide mediated co-polymerisation of maleimides with styrene (10) can also be used to control the molecular weight distribution of maleimide polymers. For example, Lokaj and co-workers have shown that heating maleimide (86) and styrene (10) with TEMPO (15) can lead to a maleimide-styrene co-polymer (87) with a low PDi and good thermal stability (Scheme 50).99
PhD_Thesis_4-10-12.docx