Polymeric materials
Polymers comprising polyetheretheretherketone and polyetherdiphenyletherketone and polymers comprising polyetheretheretherketone and polyetheretherethersulphone are described which have advantageous Tn and/or Tg properties.
1. A polymeric material having a repeat unit of formula I:
and a repeat unit of formula II:
wherein said polymeric material includes 60-80 mole % of units of Formula I and 20-40 mole % of units of Formula II; and
wherein the sum of the mole % of units of Formula I and II in said polymeric material is at least 95 mole %;
said polymeric material having a Tm of less than 298° C.
2. A material according to claim 1 , wherein the Tg of said polymeric material is greater than 120° C., and the difference between the Tm and Tg is at least 140° C.
3. A material according to claim 1 , wherein said polymeric material has a crystallinity measured by DSC of at least 20%.
4. A material according to claim 1 , wherein the melt viscosity (MV) of said polymeric material is at least 0.06 kNsm −2 and is less than 1.00 kNsm −2 .
5. A material according to claim 1 , wherein said polymeric material includes 70-80 mole % of units of Formula I and 20-30 mole % of units of Formula II.
6. A material according to claim 1 , wherein the ratio defined as the mole % of units of Formula I divided by the mole % of units of Formula II is in the range 2.3 to 4.
7. A material according to claim 1 , wherein said polymeric material is part of a composition which includes said polymeric material and a filler means, wherein said filler means is selected from a fibrous filler or a non-fibrous filler.
8. A material according to claim 7 , wherein said composition includes 20-70 wt % of said polymeric material and 30-80 wt % of filler means.
9. A material according to claim 7 , wherein said filler means is selected from glass fibre, carbon fibre, carbon black and a fluorocarbon resin.