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n-Dodecyl mercaptan (DDM) chain transfer agent and 1,6-hexanediol diacrylate (HDDA) cross-linker were used to manipulate latex properties in a monomer-starved seeded semi-continuous emulsion polymerization of butyl acrylate (BA), fluorine monomer dodecafluoroheptyl methacrylate (DFMA) together with acrylic acid (AA) and 2-hydroxyethyl acrylate (HEA). The influences of both DDM and HDDA on the particle size of the latex, as well as on the gel content, thermostability (differential scanning calorimeter and thermal gravimetric analysis), surface properties (X-ray photoelectron spectra (XPS), contact angle analysis and atomic force microscopy), and viscoelasticity (N,N-dimethylacrylamide) of the polymer films were investigated. The results showed that the introduction of DDM and HDDA has no significant effects on the final particle size of the fluorinated pressure-sensitive adhesives (PSA) latexes. XPS analysis indicated that the fluoroalkyl groups had the tendency to enrich on the surface of the film. However, this enrichment of fluorine on the film surface was reduced after the introduction of HDDA, while increased with the addition of DDM. It was also found that the gel content, glass transition temperature (Tg), thermal stability, surface roughness, and modulus (G′, Gʺ) of the fluorinated latex PSA were all increased with the introduction of HDDA. Nevertheless, opposite trends were observed for the latex after the addition of DDM. Finally, the effects of DDM and HDDA on the adhesive properties (i.e. loop tack, peel strength and shear strength) of the fluorinated latex PSA were also evaluated. [ABSTRACT FROM AUTHOR]

Fluorinated acrylate emulsion pressure sensitive adhesives (PSA) based on butyl acrylate (BA), fluorine monomer dodecafluoroheptyl methacrylate (DFMA), acrylic acid (AA) and 2-hydroxyethyl acrylate (HEA) were synthesized via a monomer-starved seeded semi-continuous emulsion polymerization process. The influences of DFMA on the resultant latex and PSA properties were comprehensively investigated. FTIR analysis indicated that DFMA could be successfully introduced into the latex PSA copolymer through emulsion polymerization. DSC and TG analyses showed that T g and thermal stability of the PSA were both improved as DFMA content increased. XPS analysis indicated that fluoroalkyl groups had a tendency to enrich on the surface of the film, and the more DFMA added the more F content on the film surface. Moreover, the surface roughness and contact angle of the acrylate latex PSA film were both increased with the introduction of DFMA. Dynamic mechanical analysis (DMA) and adhesive property tests showed that the storage modulus (Gʹ) and shear holding power were improved with DFMA content while at the sacrifice of loop tack. Finally, 180° peel strength of fluorinated acrylate latex PSAs on different substrates (PP, SS) as a function of DFMA content was evaluated. [ABSTRACT FROM AUTHOR]

Sustainable bio-based monomer isobornyl methacrylate (IBOMA) was evaluated as an alternative to traditional petroleum-based methyl methacrylate (MMA) as hard monomer in the application of acrylic latex pressure sensitive adhesive (PSA). The influence of bio-based IBOMA on the viscosity and particle size of the latexes and the gel content, sol molecular weight (M w , M n) and adhesive properties (loop tack, peel strength and shear strength) of the PSA copolymers were investigated. In addition, transmission electron microscopy (TEM), nuclear magnetic resonance (NMR), contact angle analysis, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and dynamic mechanical analysis (DMA) were used to characterize the structure and properties of latexes and corresponding films. Results were compared with those obtained when using traditional petroleum-based hard monomer MMA. Some interesting phenomena and results were indeed obtained in this work. This article will not only enrich the application of bio-based monomer IBOMA in the field of acrylic emulsion PSA, but also provide sustainable methods for the preparation of high performance acrylic emulsion PSAs (e.g. high water resistance and high cohesion emulsion PSAs). [ABSTRACT FROM AUTHOR]