PBOXProjects Based on Exchange (AIESEC program)
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The ExtPEEA-50 structure and chain extension between terminal HOOC-- groups of PrePEEA-50 and PBOX were verified by [sup.1]H-NMR characterization.
As the PrePEEAs have hydroxyl numbers higher than 20.53 mg KOH/g and acid values higher than 37.86 mg KOH/g, CBC and PBOX were used as combination chain extenders to obtain high molecular weights.
As PrePEEA-30, PrePEEA-40, PrePEEA-50, and PrePEEA-60 all had high hydroxyl number and acid value, CBC and PBOX were used in chain extension.
PrePEEAs were chain-extended at 200[degrees]C using CBC and PBOX as combination chain extenders.
AA/HEOA [SnCl.sub.2] Av/Qv (mg [M.sup.c] (molar (wt%) .KOH/g) ratio) PrePEA(0.4)-1 1.20 -- 50.0/14.9 1728.8 PrePEA(0.4)-2 1.20 0.05 47.1/11.3 1921.2 PrePEA(0.4)-3 1.30 0.05 54.3/11.5 1705.2 PrePEA(0.4)-4 1.30 0.05 51.8/2.8 2054.9 ([(eta])) [T.sub.p][d.sup.d] [SnCl.sub.2] (dl/g) ([degrees]C) (wt%) PrePEA(0.4)-1 0.081 200 -- 200 0.30 180 0.30 PrePEA(0.4)-2 0.097 180 0.20 PrePEA(0.4)-3 0.083 180 0.20 0.10 PrePEA(0.4)-4 0.097 200 0.15 TSA ([(eta])) (wt%) (dl/g) PrePEA(0.4)-1 0.1 0.18 -- 0.32 -- 0.20 PrePEA(0.4)-2 0.05 0.43 PrePEA(0.4)-3 0.05 0.44 0.05 0.47 PrePEA(0.4)-4 0.05 0.36 PBOX and ABC were effective chain extenders in the chain extension of ihe HOOC- or HO- tenninated polymers such as polyesters and polyamides to increase the molecular weight in short lime (18.
Table 1 shows the chain extension of the PrePEA(0,4)s with PBOX and ABC as combined chain exlenders.
Table 2 shows the properties of the PrePEAtO, 8)s and their chain extension with PBOX and ABC.
It verified that chain extension look place between the HOOC- tenninal groups of the PrePBA(t), 4 is and the chain extender PBOX. As chain extension between the HO- terminal groups of the PrePEA(0.
m)s and the chain ex-lender PBOX. The weak peak at 3071 cm1corresponded lo the H-C stretching vibration of the aromatic -ChHu units in the lerephthalamide dieslers units (III).