Effect of Natural Rubber Contents on Biodegradation and Water Absorption of Interpenetrating Polymer Network (IPN) Hydrogel from Natural Rubber and Cassava Starch

Abstract

Interpenetrating polymer network (IPN) hydrogel based on crosslinked natural rubber (NR) latex and crosslink cassava starch (St) was successfully prepared by a solution blending technique. Crosslinked NR latex was firstly prepared in emulsion state at 70°C by using potassium persulfate as initiator and N, N'-methylene-bis-acrylamide (MBA) as crosslinker. Secondly, the crosslinked NR latex was mixed then with gelatinized cassava starch and maleic acid (MA) as crosslinker for starch at ambient temperature by using mechanical stirrer. Finally, the mixture was casted on a glass mould to form IPN NR/St sheet via crosslinked reaction at 120 o C in oven for 1.5 h. The water absorption, tensile properties, gel and soluble fraction in water as well as biodegradation of IPN NR/St hydrogels were investigated. It was found that water absorption, soluble fraction, biodegradation and tensile properties decreased with increasing NR contents, while gel fraction in water and elongation at break increased. This was because the rubber molecules prevented the hydrogel from dissolution in water and degraded by microorganism. Furthermore, by immersion of IPN NR/St for long time, water absorption of hydrogel increased with increasing rubber contents due to the effect of elasticity of rubber molecule to easy expansion of INP NR/St hydrogel.

Assessment of mechanical performance, thermal stability and water resistance of novel conductive poly(lactic acid)/modified natural rubber blends with low loading of polyaniline

“…As LNR was incorporated into the PLA, the moisture absorption increased to 0.85% as compared to that of PLA. The hydrophilicity was imparted by the LNR component which possessed higher hydrophilicity after modification from natural rubber through unsaturated double bonds, although raw natural rubber is a well‐known hydrophobic polymer . Meanwhile, the addition of PANI did not show significant changes in the moisture absorption compared to PLA/LNR.…”

Preparation of pH‐responsive crosslinked materials from natural rubber and poly(4‐vinylpyridine)

“…The rubber samples were then immersed in toluene at room temperature for one week. The crosslink density was calculated using the Flory–Rehner equation: where p c is the crosslink density (mol m −3 ), V s is the molar volume of toluene (1.069 × 10 −4 m 3 mol −1 ) at 25 °C, χ is the interaction parameter (0.44 + 0.18 V r 0 ) and V r 0 is the fraction of rubber in the swollen gel, which can be calculated as follows: where ρ s and ρ r are the densities of toluene (0.87 g mL −1 ) and rubber (0.92 g mL −1 ), respectively, and W S and W D are the weights of swollen and dried rubbers, respectively…”

Influence of hydrostatic pressure on water absorption of polyoxymethylene: experiment and molecular dynamics simulation

“…MD simulation, which is integrated with an iterative solution of Newton's equation of motion, is one of the most fundamental methods available for studying physical properties, typically like diffusivities and their corresponding residence times, through analyzing adequately penetrating trajectories of the atoms of a substance . In the past decades, much research based on MD simulation has been reported on the behavior and mechanism of small molecules: typically like O 2 , CO 2 , and N 2 to diffuse into polymers, metals, or minerals . In addition, MD simulation can allow observing the real‐time process of water absorption and analyzing water absorption behavior of polyoxymethylene under different hydrostatic pressures.…”