Water‐swelling elastomer prepared by in situ formed lithium acrylate in chlorinated polyethylene

Abstract

Lithium acrylate (LiAA) was in situ prepared in a chlorinated polyethylene (CPE) matrix through the neutralization of lithium hydroxide (LiOH) and acrylic acid (AA) during mixing. The obtained compounds were vulcanized with dicumyl peroxide (DCP). The in situ preparation and polymerization of LiAA were characterized with Fourier transform infrared spectrometry. The crosslink density analysis results indicated that the CPE/LiAA vulcanizates contained both covalent bonds and ionic bonds. The effects of the DCP and LiAA contents on the mechanical properties and water-swelling properties of the CPE/LiAA vulcanizates were studied. The relationship between the LiOH/AA molar ratio and the properties of the CPE/LiAA vulcanizates was investigated. The results showed that LiAA could improve the mechanical and water-swelling properties of CPE/LiAA vulcanizates, providing a new approach to the preparation of water-swelling elastomers.

Flammability of EVA/IFR (APP/PER/ZB system) and EVA/IFR/synergist (CaCO3, NG, and EG) composites

“…By measuring the time to ignition (TTI), mass loss rate (MLR), total heat released (THR), and heat release rate (HRR), smoke production rate (SPR), and total smoke release (TSR), the flammability of the materials can be quantified 61–63. Especially HRR, which is a very important parameter, can be used to express the intensity of a fire 64. A highly flame retardant system normally shows a low HRR value.…”

Influence of Ethylene Ionomers on the Electrical Properties of Crosslinked Polyethylene

“…[15,16] When the -COOH group is transformed into a -COO À group, the characteristic absorption peak appears at around 1 570 cm À1 . Thus, when EAA was neutralized completely by NaOH in XLPE, the characteristic absorption peak would appear at around 1 570 cm À1 , corresponding to -COO À in the spectrum of XLPE/EAA-1.0Na blend.…”

“…Thus, when EAA was neutralized completely by NaOH in XLPE, the characteristic absorption peak would appear at around 1 570 cm À1 , corresponding to -COO À in the spectrum of XLPE/EAA-1.0Na blend. [15,16] So the spectral change indicates that the -COOH group in EAA [ Figure 2(b)] has transformed into the -COO À group in XLPE/EAA-1.0Na [ Figure 2(c)], suggesting that EAA reacted with NaOH and formed EAA-1.0Na ionomers.…”

In situ formed internal water channels improving water swelling and mechanical properties of water swellable rubber composites

“…Water‐swellable rubbers (WSRs) are a new kind of elastomeric functional material. They possess the properties of general elastomers and they also possess swelling ability when immersed in water . Water molecules can enter into WSRs by different mechanisms such as diffusion, capillarity, and surface adsorption.…”