Preparation and Swelling Behavior of L-Lactide Interpenetrating Networks

Zainab J Sweah,Hadi S Al-Lami,Athir M Haddad

doi:10.4236/ojopm.2016.64012

Abstract

Novel triblock copolymers of poly (L-lactide)-poly (ethylene glycol)-sebacate-poly (ethylene glycol)-poly (L-lactide) were synthesized by Ring-Opening Polymerization of different ratios of L-lactide with other three pre-prepared poly (ethylene glycol)-sebacate-poly (ethylene glycol) polymers, coded A, B and C which had different poly (ethyleneglycol) chain lengths. The copolymers were characterized by FTIR and 1H NMR spectroscopy, which indicated that the reaction of ROP took place and led to producing nine triblock copolymers having new different lactide chain lengths (n = 10, 25 and 50), AL10, AL25, AL50,BL10, BL25, BL50, CL10, CL25, and CL50. Nine polymer networks were also prepared from copolymers with sodium alginate S1 - S9 and finally mixed with a solution of hydroxyl ethyl cellulose to form SH1 - SH9.

Highlights

In polymer chemistry, Ring-Opening Polymerization (ROP) is a form of chain-growth polymerization
The copolymers were characterized by FTIR and 1H NMR spectroscopy, which indicated that the reaction of ROP took place and led to producing nine triblock copolymers having new different lactide chain lengths (n = 10, 25 and 50), AL10, AL25, AL50,BL10, BL25, BL50, CL10, CL25, and CL50
The intensity of the hydroxyl group band was decreased with increasing PEG molecular weight, the same observation was made by Jalal and Al-Lami [13]

Summary

Introduction

In polymer chemistry, Ring-Opening Polymerization (ROP) is a form of chain-growth polymerization. At the terminal end of a polymer chain, it acts as a reactive center where further cyclic monomers can react by opening its ring system and form a long polymer chain. The propagation center can be radical, anionic or cationic Some cyclic monomers such as lactide and glycolide can be polymerized to high molecular weight polymers by using metal catalysts. The activation of initiating and propagating alcohols by strong nonionic bases can be utilized to enable the polymerization of strained cyclic ester monomers, such as lactide. Haitao Qian, et al [8] used DBU, a known, effective, and convenient organ catalyst, for the ring opening polymerization of cyclic esters, to synthesize random copolymers of lactide and glycolide. DBU is a strictly hindered amidine that has demonstrated usefulness in a variety of different reactions

Materials

Instruments

Preparation of Polymers

Results and Discussion

Conclusion