Pre-Vulcanization of Large and Small Natural Rubber Latex Particles: Film-Forming Behavior and Mechanical Properties

Abstract

© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim The pre-vulcanized large rubber particle (LRP) and small rubber particle (SRP) latices are independently prepared to investigate their film-forming process and mechanical properties after being cast into films. The surface morphologies and roughness of both LRP and SRP films are found to be dependent on crosslink densities. The networks inside each rubber particle (RP) restrict particle deformation resulting in residual contour of RP within the film surface. For highly crosslinked RP, the collapse of the top surface of the RPs in the LRP films appears to create many “crater-like” structures within the film surfaces, while they present only protruding particles within the SRP and blend films. This seems to indicate that LRPs are easier to coalesce and form film than SRPs. Additionally, dynamic and mechanical properties and strain-induced crystallization (SIC) behaviors of the latex films, are effectively enhanced after pre-vulcanization. The pre-vulcanized LRP films perform better tensile properties and SIC than the SRP can.