International Conference and Exhibition on Polymer Chemistry November 14-16, 2016 Atlanta, Georgia, USA

Regina Aparecida Correia Gonçalves has completed her PhD in Organic Chemistry from State University of Campinas. She has experience in Chemistry with emphasis on Biocatalysis and Biotechnology of Medicinal Plants, acting on the following topics: Biocatalysis, production of primary and secondary metabolites in plant cell cultures, isolation and identification of bioactive substances of natural origin as fatty acids and polysaccharides.

Stevia rebaudiana (Bertoni) is widely studied due to foliar steviol glycosides. Recently, fructan-type polysaccharides were isolated from its roots. Fructans are reserve carbohydrate with a linear structure consisting of (2→1)-linked β-D-fructofuranosyl units, used in food industry as dietary fiber, prebiotic compound, replacement for fat and sugar and texturizing agent. Lyophilized and milled S. rebaudiana adventitious roots were extracted with water under reflux conditions at 80°C for 5 h. The aqueous extract was filtered, concentrated in a rotary evaporator and precipitated with ethanol P.A. 1:3 (v/v). The ethanolic supernatant was analyzed by off-line ESI/MS in positive mode and the monosaccharide composition was determinated by GC/MS after hydrolysis and derivatization (oxime-silylated) of the polysaccharide. The yield of the ethanolic fraction was 24% (dry weight). The off-line ESI/MS mass spectrum showed peaks corresponding to fructan-like polysaccharides that produced characteristic peaks with potassium adducts [M + K]+. The peaks at m/z 544, 706, 868, 1030, 1192 and 1354 corresponding fructo-oligosaccharides (FOS) molecules with degree of polymerization (DP) ranging from 3 to 8, respectively. From the monosaccharide composition by CG/MS experiment was possible to identify only molecules of fructose and glucose compared with mass spectrum and retention time of glucose and fructose standard analyzed at the same conditions. In the chromatogram was possible identify majority peaks corresponding to fructose units at retention time 8.6, 9.5 and 9.8 min. The data allowed the identification of FOS molecules with low DP from ethanolic fraction of S. rebaudiana roots.

José Eduardo Gonçalves has completed his PhD in Inorganic Chemistry from State University of Campinas. He has experience in Chemistry with emphasis on Analytical Chemistry and Biotechnology, acting on the following topics: Microorganisms immobilization, identification of bioactive substances and gas chromatography and mass spectrometry.

Stevia rebaudiana Bertoni, a perennial shrub of South America, that produces diterpene glycosides used as sweeteners. Recently inulin molecule was isolated from its roots, which is a polysaccharide of great interest in the food industry, and for technological applications. For commercial purposes it is necessary to know the accumulation profile of inulin during plant development. S. rebaudiana was cultivated in pots at greenhouse conditions. The plant development was evaluated by four months. S. rebaudiana roots were dried and milled, extracted with water under reflux. The aqueous extract was filtered, concentrated in a rotary evaporator and precipitated with ethanol 1:3 (v/v). After centrifugation (6000 x g/20 min) the precipitate fraction was lyophilized. Determination of the degree of polymerization (DP) for six inulin extracts, one for each cut, was calculated using the quantitative data of the fructose and glucose obtained by GC/MS after hydrolyze and derivatization (oxime-silylate). Quantitative analyses were carried out by internal standard method (myo-inositol) for each monosaccharide (glucose and fructose). The average yield of the extracts in the first three cuts (6.25% dry weight) was less than that observed in the final cut after flowering plant (27.60%). The extracts obtained during the vegetative phase of the plant (two first months), showed fructans molecules with low DP ~ 5, nominated fructooligosaccharides (FOS). Inulin molecules with DP>20 were observed after flowering stage. The data showed that inulin molecules are produced with higher yield and DP after flowering of S. rebaudiana.

Xu Jin has completed her PhD in Chemistry in 2015 from National University of Singapore and is currently working in the interfacial areas of synthetic organic chemistry, polymer chemistry and biologically interesting chemical substances at the Institute of Chemical and Engineering Sciences of A*Star, Singapore.

Recently, the Wittig reaction involving stabilized phosphorus ylides has been utilized as a bioconjugation strategy featured by its ability to tolerate aqueous media as well as metal free. However, such potentially more useful reaction is pretty much under explored, partially due to its poor atom efficiency and the generation of triphenylphosphine oxide by-product. In our efforts to explore for broader applications of Wittig olefination, we took use of these disadvantages and designed a cyclic phorous ylide template which could be potentially used for development of nonionic surfactant. As it is known, current nonionic surfactants generally have little variations in their hydrophobic and hydrophilic cores mainly due to the synthetic challenges. In this presentation, we demonstrate the synthesis of a stabilized cyclic triphenylphosphonium containing ethylene glycol oligomer as versatile tools for traceless conjugation with aliphatic aldehydes. Such Wittig olefination would naturally incorporate phosphine oxide as part of the olefinic product and avoid its release to the surroundings. The resulting conjunction products are amphiphilic which could be potentially used as nonionic surfactants.

Bhavya Singhi is in the process of completing her MS in Textile Chemistry and plans to pursue a PhD in Fiber and Polymer Science at North Carolina State University, Raleigh. She graduated in 2014 with a BTech degree in Fibers and Textile Processing Technology from the Institute of Chemical Technology, Mumbai, India. She has worked on various projects involving polymer technologies such as encapsulation, extrusion and synthesis. Her research interests include polymer degradation, biopolymers and non-woven fabrics.

Polyhydroxyalkanoates (PHAs), known as bacterial polyesters, are considered novel polymers because of their biodegradability. A wide range of hydroxyalkanoate units, such as butyrates and valerates, are produced by bacterial synthesis. These units can be polymerized and copolymerized with varying mechanical and structural properties. Due to their biocompatibility, PHAs have been introduced in the fabrication of medical products, such as sutures and wound dressings. Some studies have explored the use of bacterial polyester for controlled release applications with thermally sensitive chemicals and drugs. Since PHAs are melt spun at temperatures as high as 200°C, this requires a post-spinning stage for chemical and drug incorporation. Hence, there is a need for low temperature spinning of bacterial polyester to prevent drawbacks of post-spinning drug incorporation, such as a non-uniform absorption that leads to an uneven release profile. To achieve this goal, we analyzed PHA solubility properties to develop a solvent spinning process at low temperature. Next we compared dissolution of poly(3-hydroxybutyrate-4-hydroxybutyrate) (P34HB) in multiple solvents such as tetrahydrofuran, dioxane, methylene dichloride and chloroform. This solvent study found methylene dichloride as the most suitable solvent. As a result, spinning dopes of various concentrations were coagulated and regenerated as polymer films in methanol at different temperatures to determine the optimal coagulating conditions. Currently, we are working on the production of continuous filaments using this solvent spinning process. This study would help in developing a single step process for drug incorporation during fiber spinning, which can be utilized for drug delivery applications.

Jongshin Park has completed his PhD from North Carolina State University in 1988. He is the Professor of Department of Biosystems and Biomaterials Science and Engineering, Seoul National University. He has published more than 40 papers in reputed journals and has been serving as a Member of Korean Fiber Society.

Hydrogels are hydrophilic, three-dimensional and expandable matrices that are produced through chemical and/or physical crosslinking of certain polymers. These cross-linked polymers have excellent characteristics, such as swelling, mechanical, permeation, surface and optical properties. In some cases, polysaccharide-based hydrogels have been prepared from a single polysaccharide such as carboxymethyl cellulose (CMC) and starch. In particular, oxidative modification of starch is carried out in order to improve the functionality of compound. The hydroxyl groups, primarily at C-2, C-3, and C-6 positions, are transformed to aldehyde and carboxylic acid by oxidation. In this study, starch aldehyde was formed by oxidation. Polysaccharide hydrogels were prepared by chemical reaction of CMC and starch aldehyde with cross-linker. Epichlorohydrin (ECH) or citric acid was used for crosslinking. The number of aldehyde substitution (DS) was estimated from chemical titration. Depending on the amount of oxidants, the DS of starch aldehydes ranged from 0.47 to 1.52. In case of ECH crosslinking, carboxylate and hydroxyl groups of polysaccharides attack to either epoxide or CH2Cl groups of ECH to form ester linkage. In case of citric acid crosslinking, ester linkage was formed because of anhydride formation and crosslinking between polysaccharide and citric acid. The maximum swelling ratio of hydrogel was about 32.