Subject: Chemistry And Materials Science, Polymers And Plastics Keywords: thermoplastic vulcanizates (TPVs); dynamic vulcanization; morphology evolution; crystallization behavior
Online: 24 July 2019 (12:10:36 CEST)
As a special class of “green” elastomers, thermoplastic vulcanizates (TPVs) have been widely used in industries due to the combination of the excellent resilience of conventional elastomers and the easy recyclability of thermoplastics. Here, the morphology evolution of TPVs based on polyamide 6/ethylene-propylene-diene rubber (PA6/EPDM) blends was investigated by varying the content of the curing agent, phenolic resin (PF). With the incorporation of 6 wt% PF, the gel content of the EPDM phase reaches a high value of 49.6wt% and a typical sea-island structure is formed with EPDM domain in a micro-nano size. The dynamic rheology behaviors of TPVs showed that with the curing degree of EPDM phase increasing, a denser network of EPDM particles is formed in PA6 matrix. Also, a lower crystal degree and crystal peak temperature are observed, indicating that the presence of a growth restriction of PA6 crystal plate induced by a thinner plastic layer between the adjacent EPDM particles. However, the crystal form of PA6 is not changed with the increasing curing degree of the EPDM phase. This study provides an effective strategy to realize a new kind of TPVs, which can be easily introduced into industrial applications.
ARTICLE | doi:10.20944/preprints202307.1080.v1
Subject: Biology And Life Sciences, Food Science And Technology Keywords: Thawing methods; Frozen pork; Moisture distribution; Water holding capacity; Microstructure
Online: 17 July 2023 (08:39:05 CEST)
The effect of seven different thawing methods (atmospheric temperature thawing (AT), microwave thawing (MT), microwave magnetic nanoparticles thawing (MMT), microwave vacuum thawing (MVT), far-infrared thawing (FT), far-infrared magnetic nanoparticles thawing (FMT) and far-infrared ultrasonic thawing (FUT)) on water mobility and microstructure of frozen pork was examined. The results showed that the thawing loss, cooking loss, and centrifugal loss of MVT treatment were lower than those of other thawing methods. The results of LF-NMR and NMRI showed that in MVT and FUT treatment, the proportion of bound water and non-flowing water increased, while the proportion of free water decreased. The microstructure was significantly improved by microwave or far-infrared thawing assisted by magnetic nanoparticles, and the frozen pork samples had a more compact and granular microstructure. In summary, MVT and FUT improved the quality of thawed meat and have broad potential applications in thawing meat.
ARTICLE | doi:10.20944/preprints201812.0263.v1
Subject: Chemistry And Materials Science, Applied Chemistry Keywords: Amino acid ionic liquid; phase change solvent; high CO2 absorption capacity; mechanism of phase change; recycling ability
Online: 21 December 2018 (15:26:24 CET)
As novel materials for carbon capture, phase change solvents can separate into two immiscible phases during the CO2 capturing procedure under a certain temperature. The solvent systems can significantly decrease the energy consumption since the solvents can be regenerated by only heating the rich-CO2 phase. In this work, amino acid ionic liquids (AAILs) were synthesized using quaternary ammonium salts and amino acids as raw materials, and the aqueous solutions were prepared as novel liquid-solid phase change solvents. The results showed that the solvents had excellent CO2 absorption capacity, and the AAILs functionalized by glycine and tryptophan exhibited significant phase change properties. The mechanism of phase-change of the solvent were mainly due to the lower solubility of the product after reaction between AAILs and CO2. The solvent with tryptophan as anion could be regenerated by only heating the CO2-riched solid phase, which might significantly decrease energy consumption of regeneration. And the absorbent could be reused with the regenerated absorption ratio up to 79%. The solvent system has great potential in industrial application due to the easy operation process and efficient recycling ability.