Modification of polysulfide sealant with polysulfide polythio‐urethane‐urea

Abstract

With a small amount of isocyanate-terminated polysulfide (NCO-PSF-NCO) as additive, the commercial polysulfide-based sealant had significant improvement in mechanical properties. The test results showed that 5% of NCO-PSF-NCO could help to rise 50% in the tensile strength and 27% in the ultimate elongation of the polysulfide sealant. The adhesive strength to substrates such as steel, epoxycoated or polyurethane-coated surface also increased significantly. Dynamic mechanical thermal analysis and differential scanning calorimetry analysis revealed that formed polysulfide polythio-urethane-urea (polysulfide-urea) contributed to a slight increase in the T g of the polysulfide sealant. It might be due to the domains of polysulfide-urea, which had effects of physical crosslinking and chain-extending on the polysulfide sealant. However, the introduction of polysulfide-urea structures had no appreciable influence on oil resistance of the polysulfide sealant.

Effect of filler on the compression set, compression stress–strain behavior, and mechanical properties of polysulfide sealants

“…Many publications can be found on the characterization of polysulfide cured by metal peroxides,5–9 reporting the results of thermogravimetry analysis, dynamic mechanical analysis, tensile strengths, and hardness testing. Thermal stability and photodegradation of the liquid polysulfide and cured polysulfide were also studied by Mahon et al10, 11 In our earlier research work, structure, mechanical properties, and modification of polysulfide‐based sealants have been studied 12–16…”

The preparation and physical properties of polysulfide-based elastomers through one-pot thiol-ene click reaction

“…These cross-linked elastomers derived from PSF oligomers have high resistance to UV radiation and the environment, exhibit good low-temperature properties, low water-vapour transmission, and resist solvents and chemicals. Our earlier works have also studied metal oxide or isocyanate cured polysulfide polymer [24][25][26] and explore kinetic analysis of polysulfide-acrylate click reaction by dielectric analyzer and dynamic mechanical analyzer [27]. Here, we successfully prepared polysulfide-based elastomers by reacting PSF oligomers with bisphenol-A diacrylate resin through one-pot thiol-Michael addition reaction, in which tris(dimethylaminomethyl)-phenol (DMP-30) was used as a catalyst.…”

The effect of epoxy resin to reduce the compression set of polysulfide sealant

“…Many publications can be found on the characterization of polysulfide sealants,5–11 reporting the results of thermogravimetry analysis, dynamic mechanical analysis, tensile strengths, hardness testing, thermal stability, and photodegradation of the liquid polysulfide and cured polysulfide. In our earlier work, structure, mechanical properties, and modification of polysulfide‐based sealants have been studied 12–16…”

“…In our earlier work, structure, mechanical properties, and modification of polysulfide-based sealants have been studied. [12][13][14][15][16] Taking the advantage of lower cost, polysulfide sealants continue to be the dominant part of the elastomeric sealants. However, they are facing strong challenges from silicone and polyurethanebased sealants.…”