Thermoplastic mung bean starch/natural rubber/sericin blends for improved oil resistance

Int J Biol Macromol. 2021 Oct 1:188:283-289. doi: 10.1016/j.ijbiomac.2021.07.187. Epub 2021 Jul 31.

Abstract

Oil resistant thermoplastic elastomers (TPE) were prepared using mung bean thermoplastic starch (MTPS) blending with rubbers and sericin. Sericin was incorporated into MTPS as a compatibilizer. MTPS with sericin (MTPSS) was blended with natural rubber (NR) and epoxidized NR (ENR). Sericin at 5% improved the tensile strength (10 MPa), elastic recovery (52%) and morphology of the MTPSS/ENR blend. The mechanical properties, elastic recovery and morphology of the MTPSS5/NR blend were improved by the addition of ENR. The MTPSS/ENR showed palm (28%) and motor oils (8%) swelling resistance because of the hydrophilicity of MTPS and high polarity of ENR. The MTPSS/ENR/NR showed gasoline swelling resistance (104%) because of the hydrophilicity of MTPS and low polarity of NR. FTIR confirmed a reaction between the -NH groups of sericin and the epoxy groups of ENR. This reaction improved the compatibility, mechanical properties, elastic recovery, morphology and oils swelling resistance of the blends.

Keywords: Epoxidized natural rubber; Mung bean; Oil resistance; Sericin; Thermoplastic elastomer; Thermoplastic starch; Vigna radiata.

MeSH terms

  • Biochemical Phenomena
  • Elastomers / chemistry*
  • Epoxy Compounds / chemistry
  • Oils / adverse effects*
  • Oils / chemistry
  • Plastics / chemistry*
  • Rubber / chemistry
  • Starch / chemistry
  • Temperature
  • Tensile Strength / drug effects

Substances

  • Elastomers
  • Epoxy Compounds
  • Oils
  • Plastics
  • Starch
  • Rubber