Maillard Reaction in Natural Rubber Latex: Characterization and Physical Properties of Solid Natural Rubber

Abstract

Maillard reaction in Natural Rubber (NR) latex was investigated by treating fresh NR latex with glutaraldehyde (C5H8O2) in amounts of 0, 50, 100, and 200 mmol/kg of latex. Protein cross-linking in fresh NR latex and solid NR was confirmed by using sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE) and attenuated total reflection infrared (ATR-IR) spectroscopy, respectively. It was found that degree of protein cross-linking in NR increased with increasing C5H8O2concentration. Physical properties of untreated and treated NR substances in terms of gel content, initial Wallace plasticity (P0), plasticity retention index (PRI), Mooney viscosity, and tensile strength were carefully explored. Results clearly showed that the Maillard cross-linking of proteins had remarkable effect on bulk NR properties, that is, solvent resistance, hardness, resistance to oxidation, rheological behavior, and resistance to stretching out.

Effect of Stabilizer States (Solid Vs Liquid) on Properties of Stabilized Natural Rubbers

“…This test estimates the resistance to oxidation and breakage of rubber molecules at higher temperatures. Similar to the Po results, the PRI values of NR with stabilizer samples were stable, unlike the PRI value of the control NR sample, which decreased after 12 weeks of storage time [13]. Concerning the rigidity or storage modulus (G') of NR samples as a function of strain, its values for 0 and 12 weeks can be seen in Figure 5.…”

“…However, the latex samples showed a Mooney viscosity lower than the samples from dry rubber. After 12 weeks, the Mooney viscosity increased for the control sample, which is a sign of the storage hardening phenomenon of natural rubber [13]. However, the NR samples supplemented with hydroxylamine sulfate were stable (NRD/0.2HS, NRD/2.0HS, NRL/0.2HS, and NRL/2.0HS).…”

“…The FTIR spectra of the NR with hydroxylamine sulfate samples presented at 3600-2600 cm −1 and 1800-1600 cm −1 . At time 0, samples showed peaks for the amine group (N-H) at 3280 cm −1 , the fatty acid ester group at 1740 cm −1 , the aldehyde group at 1710 cm −1 , and the amide I group at 1660-1630 cm −1 [13]. After 12 The gel content of the rubber samples was also interesting for investigating the effect of stabilizer states (solid vs liquid), and the amounts of gel content are shown in Figure 3.…”

“…The FTIR spectra of the NR with hydroxylamine sulfate samples presented at 3600-2600 cm −1 and 1800-1600 cm −1 . At time 0, samples showed peaks for the amine group (N-H) at 3280 cm −1 , the fatty acid ester group at 1740 cm −1 , the aldehyde group at 1710 cm −1 , and the amide I group at 1660-1630 cm −1 [13].…”

Aplikasi asetaldehida melalui teknik perendaman terhadap karakteristik mutu teknis karet alam

“…Faktor utama yang mempengaruhi nilai PRI adalah pertimbangan antara prooksidan dan antioksidan dalam karet (Solichin, 1991). Semakin tinggi nilai PRI, maka semakin baik mutu karet (Montha et al, 2016). Gambar 1.…”