This document is the Accepted Manuscript version of a Published Work that appeared in final form in ACS Applied Materials and Interfaces 6. 7456-7463 (2014), copyright © American Chemical Society and the Division of Chemical Education, Inc., after peer review and technical editing by the publisher. To access the edited and published work see: http://pubs.acs.org/doi/abs/10.1021/am5008535 DOI: 10.1021/am5008535 1 Effect of the molecular structure of the polymer and nucleation on the optical properties of polypropylene homo- and copolymers Zsuzsanna Horváth 1,2 , Alfréd Menyhárd 1,2 , Petar Doshev 3 ,Markus Gahleitner 3 , György Vörös 1 , József Varga 1,2 and Béla Pukánszky 1,2 1 Laboratory of Plastics and Rubber Technology, Department of Physical Chemistry and Materials Science, Budapest University of Technology and Economics, H-1521 Budapest, P.O. Box 91, Hungary 2 Institute of Materials Science and Environmental Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences, 1519 Budapest, P.O. Box 286, Hungary 3 Borealis Polyolefine GmbH, St.-Peter-Strasse 25, A-4021 Linz, Austria Zsuzsanna Horváth: zshorvath@mail.bme.hu Alfréd Menyhárd: amenyhard@mail.bme.hu Petar Doshev: petar.doshev@borealisgroup.com Markus Gahleitner: markus.gahleitner@borealisgroup.com György Vörös: voros@ludens.elte.hu József Varga: jvarga@mail.bme.hu Béla Pukánszky: bpukanszky@mail.bme.hu