Film Formation Process of Natural Rubber Latex Particles: Roles of the Particle Size and Distribution of Non-Rubber Species on Film Microstructure

Publication date: Available online 10 February 2020Source: Colloids and Surfaces A: Physicochemical and Engineering AspectsAuthor(s): Manus Sriring, Adun Nimpaiboon, Sirirat Kumarn, Keiko Higaki, Yuji Higaki, Ken Kojio, Atsushi Takahara, Chee Cheong Ho, Jitladda SakdapipanichAbstractNatural rubber (NR) films from various mixing ratios of large- (LRP) and small rubber particles (SRP) were prepared through latex and solution casting methods. Film-forming behaviours of the resulting films were investigated by monitoring their surface characteristics using atomic force microscopy (AFM). When the SRP portion was higher, the surface of latex-cast films was found to be smoother as smaller particles protruded out of the surface less than larger ones did. AFM phase micrographs revealed the hexagonal shape of the packed rubber particles (RPs) in the LRP film, while RPs in the other samples were sphere-like. After aging under ambient condition, the packed RPs were flattened while retaining their RP boundaries creating supporting frameworks within the rubber matrix. On the contrary, when the rubber film was cast from a toluene solution, the characteristic of RP boundaries disappeared and became aggregates of the membrane components on the film surface. The latex-cast films performed much better in mechanical strength than the solution-cast films did due to the destruction of the supporting frameworks arisen from non-rubber components at RP boundaries of the solution-cast film. The inhomo...

Source: Colloids and Surfaces A: Physicochemical and Engineering Aspects - February 11, 2020 Category: Chemistry Source Type: research