KEMIN WANG, LIFEI HE

Journal of Polymer Materials, Vol.36, No.3, pp. 253-260, 2019, DOI:10.32381/JPM.2019.36.03.5

Abstract This study proposes a simple approach for the fabrication of microspherical catalysts with a hierarchical porous structure. The cross-linked porous microspheres with catalytic ability were prepared directly from small-molecular monomers via low-temperature phase-separation photopolymerization of water/oil suspension. The morphology, pore size, chemical structure, and thermal stability of the obtained porous microspheres were characterized by SEM, Mercury Intrusion Porosimetry, FTIR, and TGA. The porous microspheres directly served as an acid catalyst for the condensation reaction of benzaldehyde and ethylene glycol, which exhibited superior catalytic activity and recyclability. The results indicated that such porous microspheres have great potential in the application of… More >

SAURABH SAXENA^a, PRATEEK MALIK^a, GEETHA SESHADRI^a,*, AJAY K. TYAGI^a, UTTAM KUMAR MANDAL^b

Journal of Polymer Materials, Vol.36, No.1, pp. 39-51, 2019, DOI:10.32381/JPM.2019.36.01.4

Abstract Medium molecular weight liquid perfluoropolyethers (840 u to 1372 u) were synthesized by photopolymerization of hexafluoropropylene (HFP) in the presence of oxygen. Effects of various reaction parameters such as temperature, pressure, UV wattage and reaction time on yield, viscosity and molecular weight of PFPEs were studied. Out of all the parameters, the effect of reaction temperature was found the most significant on molecular weight of PFPEs. By increasing reaction temperature, viscosity and molecular weight of PFPEs where decreased. By increasing the wattage of the lamp, viscosity and molecular weight of PFPEs where also decreased. PFPEs obtained from reactions were subjected… More >

Arne Rüdiger^1,2, Peter Hendil-Forssell³, Cecilia Hedfors³, Mats Martinelle³, Stacy Trey^4,5,*, Mats Johansson^1,4

Journal of Renewable Materials, Vol.1, No.2, pp. 124-140, 2013, DOI:10.7569/JRM.2012.634109

Abstract The present study describes the use of an epoxy functional fatty acid, 9,10-epoxy-18-hydroxyoctadecanoic acid (EFA), extracted from birch (Betula pendula) outer bark to produce thermosets. The purifi ed epoxy fatty acid was polymerized by enzyme-catalyzed polycondensation utilizing Candida antarctica lipase B (CalB) to form oligomers with targeted degrees of polymerization (DP) of 3, 6, and 9 and obtained DPs of 2.3, 5.9 and 7.3, respectively. It was determined that it is possible to fi rst enzymatically polymerize and aliphatically endcap the epoxy functional fatty acid resulting in controlled oligomer lengths while also maintaining the epoxy functionality for further reaction by… More >

Beatrise Sture^1,*, Mikelis Kirpluks¹, Sergejs Gaidukovs², Edgars Vanags¹

Journal of Renewable Materials, Vol.8, No.9, pp. 1077-1089, 2020, DOI:10.32604/jrm.2020.09294

Abstract Photocurable systems are more effective, faster and require less energy than conventional thermal curing methods. To facilitate the ongoing transition toward a biobased economy, photoactive compounds were synthesized from tall oil fatty acids (TOFA) which is a by-product from wood pulping. In this study, photoactive monomers were synthesized by two different chemical pathways using oleic acid and TOFA as raw materials. Firstly, double bonds present in TOFA were epoxidized, followed by epoxy ring-opening with acrylic acid which introduced photoactive functional groups into the fatty acid backbone. Intermediates and final products were analysed using titration methods (acidic value, epoxy value, iodine… More >