Co-polyesteramides of different microstructures : synthesis, properties and fiber spinning

• Co-Polyesteramide verschiedener Mikrostrukturen : Synthese, Eigenschaften und Faserspinnen

Gupta, Manisha; Möller, Martin (Thesis advisor); Pich, Andrij (Thesis advisor)

Aachen (2016)
Dissertation / PhD Thesis

Dissertation, RWTH Aachen, 2016

Abstract

Among synthetic biodegradable polymers, aliphatic polyesteramides (PEAs) are a newclass of high performance polymers combining the properties of aliphatic polyesters andpolyamide. In this work, aliphatic PEAs of different microstructures have beensynthesized via a batch melt polycondensation process as well as continuous reactiveextrusion, and their morphology and properties have been investigated.The first part of this work focuses on the preparation of a series of PEAs, namely poly(ε-caprolactone-co-ε-caprolactam) copolymers, using a reactive extrusion process. Thecopolymers are prepared by anionic ring opening polymerization of ε-caprolactam in thepoly(ε-caprolactone) melt. The process is performed on a twin-screw microcompounder,and a quantitative monomer conversion can be achieved.Followed by the successful synthesis in a small scale, up-scaling assisted by a simulationprogram MOREX that allows calculating the residence time of the polymer melt over theentire length of the designed extruder screw has been realized on a lab extruder. With aproper screw configuration, the monomer conversion can reach more than 95 %, yieldingpolymers with significantly high molecular weight.It is important to study the spinnability of PEAs, since various textile structures are oftenused for biomedical applications, and it is a big challenge to find proper and stablespinning conditions such as take-up speed, throughput, draw-down ratio, meltingtemperature and take-up point. In this work PEAs synthesized via the reactive extrusionprocess based on anionic polymerization of ε-caprolactam in the melt of commerciallyavailable polycaprolactone were successfully spun into fibers on a microcompounderequipped with a melt spinning line.The second part of the thesis deals with the synthesis of high molecular weightpoly(esteramideamides) (PEAAs) by melt polycondensation of a tailor-made amidecontainingmonomer based on 1,4-diaminobutane and ε-caprolactone and differentdicarboxylic acid methyl esters with a varied number of methylene groups under catalysisof an organo-titanium catalyst. A series of PEAA polymers were synthesized and theirfibers were prepared via a melt spinning process. The mechanical and thermal properties of as spun and conditioned fibers were then evaluated and interpreted regarding thestructure property relationship.This work shows the incorporation of ester and amide groups in a polymer backboneleading to a new class of degradable polymers, PEAs. Both continuous and batchsynthetic procedures have been developed for their preparation. PEAs with tailor-madechemical structures have been synthesized, and they can be melt-spun into fibers of goodmechanical properties.