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ABSTRACT Application of chain-growth condensation polymerization (CGCP) to obtain well-defined polybenzoxazole (PBO) was examined. CGCP of both phenyl 3-{(2-methoxyethoxy)methoxy (MEM-oxy)}-4-(octylamino)benzoate ( 1b) ( para-substituted monomer) and phenyl 4-MEM-oxy-3-(octylamino)benzoate ( 3b) ( meta-substituted monomer) was examined in the presence of metal disilazide base and phenyl 4-nitro- or methylbenzoate 2 as an initiator. Polymerization of the latter monomer, but not the former, afforded polymer with controlled molecular weight based on the feed ratio of monomer to initiator and with a narrow molecular weight distribution. Accordingly, monomer 3c, in which the octyl group on the amino nitrogen of 3b was replaced with a 4-(octyloxy)benzyl (OOB) group, was polymerized in the presence of lithium 1,1,1,3,3,3-hexamethyldisilazide (LiHMDS), phenyl 4-methylbenzoate ( 2b), and LiCl in THF at 0 °C to yield poly 3c with well-defined molecular weight ( Mn = 4520-9080) and low polydispersity ( Mw/ Mn ≤ 1.11). Treatment of poly 3c with trifluoroacetic acid simultaneously removed the MEM and OOB groups, affording poly( o-hydroxyamide) (poly 4) without scission of the amide linkages. Cyclodehydration of poly 4 proceeded at 350 °C to yield PBO (poly 5), which was insoluble in organic solvents and acids. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 1730-1736 [ABSTRACT FROM AUTHOR]

ABSTRACT Well-defined poly(3-alkyl-4-benzamide) was synthesized by means of chain-growth condensation polymerization of phenyl 3-octyl-4-(4-octyloxybenzyl(OOB)amino)benzoate ( 1c) from initiator 2, followed by removal of the OOB groups on amide nitrogen of poly 1c. Polymerization of 1c with phenyl 4-(trifluoromethyl)benzoate ( 2b) in the presence of 1,1,1,3,3,3-hexamethyldisilazide (LiHMDS) and LiCl in THF at −10 °C gave poly 1c with a narrow molecular weight distribution ( Mw/ Mn ≤ 1.08) and a well-defined molecular weight ( Mn = 4480-12,700) determined by the feed ratio of monomer to initiator (from 10 to 30). The OOB groups of poly 1c were removed with H2SO4 to give the corresponding N-unsubstituted poly( p-benzamide) (poly 1c′) with low polydispersity. The solublity of poly 1c′ in polar organic solvents was dramatically higher than that of poly( p-benzamide), demonstrating that introduction of an alkyl group on the aromatic ring is very effective for improving the solubility of poly( p-benzamide). © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 360-365 [ABSTRACT FROM AUTHOR]

Condensation reaction of poly(ethylene glycol) (PEG) with a carboxyl group at one chain end and hyperbranched polyamide (HBPA) with a hydroxyl group at the focal point was performed in the presence of condensation agent at ambient temperature, yielding PEG ‐ b ‐ HBPAs with defined molecular weight and very narrow molecular weight distribution. PEG ‐ b ‐ HBPA formed micelles in water. [ABSTRACT FROM AUTHOR]

PolystyrENe ‐ graft ‐ poly(p ‐ bENzamide) was synthesized by free radical copolymerization of poly(N ‐ octyloxybENzyl ‐ p ‐ bENzamide) macromonomer and styrENe, followed by the removal of the octyloxybENzyl groups from amide nitrogEN. The glass transition temperature (Tg) of polystyrENe ‐ graft ‐ poly(p ‐ bENzamide) increased dramatically by 50–60 °C whEN the contENt of poly(p ‐ bENzamide) exceeded a threshold of about 4%. [ABSTRACT FROM AUTHOR]