Copolyesters (V,-V, and VI,-VZ,J derived from 2-(6-oxido-6H-dibenz(c,exl,2)oxaphosphorin-6-yl)-l,4-bis(2-hydroxyethoxy) phenylene (II) and bis(Z-hydroxyethyl) naphthalate (ZZZ)or bis(4-hydroxybutyl) naphthalate (Iv) were synthesized and characterized. Copolyesters V,-V,, VI.-VII had been characterized by inherent viscosity, solubilities, t.g.a., d.s.c., X-ray diffraction, 'H n.m.r., 31P n.m.r., UL-94 and d.m.a. D.s.c. and X-ray diffraction show that the VI series of copolyesters were crystalline polymers and the crystallinity decreased with the increase in ZZcontent, whereas the V series copolyesters were amorphous polymers. The inherent viscosity of these copolyesters ranged from 0.53 to 0.68 dl g-'. The T, values of the V series copolyesters ranged from 118 to 126°C and those of the VI series copolyesters were in the range 68-77°C; these were higher than the Ts values of polyethylene naphthalate (PEN, Ta: 116°C) and polybutylene naphthalate (PBN, Tg: 67°C). The Td values (10%) for the V series of copolyesters in nitrogen ranged from 450 to 470°C and those for the VI series copolyesters were in the range 410-415°C; these values were also higher than that of PEN (Td: 449°C) and PBN (Td: 410°C). UL-94 V-O grade could be achieved with a phosphorus content as low as 0.48 wt% for the V series and 0.97 wt% for the VI series copolyesters. T.g.a. kinetics also indicated that the V and VI series copolyesters had higher activation energies of degradation than did PEN and PBN. When these copolyphosphates were treated with fire for 10 s, intumescence is observed on the surface of copolyphosphates which retards further flaming of esters have good mechanical properties (G’: lO8-lo9 Pa) before glass transition the polymers. DMA showed that all copolyphosphate temperatures.
Посилання на статтю:
Synthesis and properties of phosphorus-containing PBN copolyesters PEN and / Chun Shan Wang , Ching Hsuan Lin // Polymer. – 1999. – N 40. – P. 747–757.