Muhammad Imran Malik, Joongsuk Oh, Syed Ghulam Musharraf, Muhammad Raza Shah, Shakil Ahmed and Muhammad Irfan
University of Karachi, Pakistan
Pohang University of Science and Technology, Korea
Posters & Accepted Abstracts: J Chromatogr Sep Tech
Architecture of polymers is an important parameter that influences their physical properties and final applications. Polymers with similar molar mass but varying architecture (such as linear to stars with different number of arms) can have very different physical properties. Therefore, characterization of polymers with regard to their architecture is imperative and at the same time very challenging. This is not achievable by conventional techniques. Modern chromatographic techniques can be the answer to such complex problems. In this study, linear and star-shaped polycaprolactones with varying number of arms are synthesized by ring opening of Ã?Â?-caprolactone. The polymers were characterized in detail to obtain information of by-products in the samples. Size exclusion chromatography could not differentiate products with similar molar mass but different architecture and if there are any byproducts in the sample. Liquid chromatography at critical conditions on NP and RP columns provided more insight into the products with regard to number of arms and possible by-products. MALDI-TOF MS analysis confirmed the structures and successful separation of targeted product from unwanted by-product. 2D-LC by coupling of LCCC to SEC in the second dimension demonstrated the similar size of the products that are separated successfully by LCCC. The purity and analysis of star-shaped precursor is imperative for further synthesis of star block copolymers that is not given much attention in recent literature. Thermal and morphological properties of the polycaprolactones with similar molar mass but different architectures are evaluated with DSC, TGA and AFM.