Synthesis of water-soluble, fully biobased cellulose levulinate esters through the reaction of cellulose and alpha-angelica lactone in a DBU/CO2/DMSO solvent system

2020 ◽  
Vol 22 (3) ◽  
pp. 707-717 ◽  
Author(s):  
Min Pei ◽  
Xinwen Peng ◽  
Yuqing Shen ◽  
Yunlong Yang ◽  
Yuanlong Guo ◽  
...  

Full biobased, water soluble and low cell cytotoxicity cellulose levulinate esters were prepared via the reaction of cellulose with α-AL, and CLE film has a tensile strength up to 72 MPa and an elongation at break up to 26.7%.

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Fahad H. Falqi ◽  
Osamah A. Bin-Dahman ◽  
M. Hussain ◽  
Mamdouh A. Al-Harthi

Water-soluble polymers such as poly(vinyl alcohol) (PVA) and poly(ethylene glycol) (PEG) and their nanocomposites with graphene were prepared by using a solution mixing and casting technique. The effect of different PEG loadings was investigated to determine the optimum blend ratio. The films were characterized using Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and thermogravimetric analyzer (TGA) methods. Also, the mechanical properties including tensile strength and elongation at break were measured using a universal tensile testing machine. FTIR results confirmed the formation of the H-bond between PEG and PVA. DSC studies revealed that PEG has a significant plasticization effect on PVA as seen by the drop in the glass transition temperature (Tg). The blend with 10 wt% PEG loading was found to be the optimum blend because of good compatibility as shown by FTIR and SEM results and improved thermal properties. PVA/PEG (10%) nanocomposites were prepared using graphene as a nanofiller. It was found that the elongation at break increased by 62% from 147% for the PVA/PEG (10%) blend to 209% for the nanocomposite with graphene loading of 0.2 wt%. The experimental values of tensile strength were compared using the predictive model of Nicolais and Narkis.


2013 ◽  
Vol 2 (4) ◽  
pp. 1-5
Author(s):  
Yudha Widyanata ◽  
Indah M.S. Sitorus ◽  
Indra Surya

By using a semi-efficient vulcanization system, Alkanolamide (ALK) was incorporated into kaolin-filled natural rubber compound at 1.0; 3.0; 5.0 and 7.0 parts per hundred rubber (phr). An investigation was carried out to examine the effect of ALK on tensile properties of the kaolin filled-natural rubber compound. It was found that ALK exhibited higher tensile modulus, tensile strength, and elongation at break up to 5.0 phr of ALK loading and then decreased with further increasing of ALK loading. Crosslink density measurement proved that 5.0 phr loading of ALK in the kaolin-filled natural rubber system exhibited greatest tensile properties due to its highest crosslink density formation.


2020 ◽  
Vol 26 (2) ◽  
pp. 62-69
Author(s):  
Farida Ali ◽  
Tuti I. Sari ◽  
Andi A. Siahaan ◽  
Al-Kautsar D. Arya ◽  
Tri Susanto

Penelitian ini untuk mengetahui pengaruh penambahan Natural Rubber (NR) dan Epoxidation Natural Rubber (ENR-46) dengan kompatibiliser Chlorprene Rubber (CR) pada aplikasi kompon termoplastik Poly Vinyl Chloride (PVC) dan Nitrile Butadiene Rubber (NBR), variabel penelitian meliputi ENR-46/PVC/NBR/CR, NR/PVC/NBR/CR dan CR-NR/PVC/NBR, CR-ENR-46/PVC/NBR. Parameter pengujian sifat fisik-mekanik : Hardness (Shore A), Tensile Strength (Mpa), Elongation at Break (%) dan ketahanan terhadap pelarut minyak (n-Pentane, Toluene, Hexane dan Pertalite). Hasil penelitian didapatkan untuk sifat fisik-mekanik, semakin banyak penambahan NR Kekerasan kompon termoplastik akan menurun, Tensile Strength dan Elongation at Break kompon akan meningkat begitu juga dengan CR-NR. Tetapi berbanding terbalik hasilnya untuk ENR-46 dan CR-ENR-46. Pengujian Ketahanan terhadap pelarut minyak semakin banyak penambahan ENR-46 Ketahanan kompon termoplastik terhadap pelarut akan meningkat, hasil yang sama juga pada CR-ENR-46. Tetapi berbanding terbalik hasilnya dengan penambahan NR dan CR-NR pada kompon termoplastik.


2020 ◽  
Vol 21 (8) ◽  
pp. 741-747
Author(s):  
Liguang Zhang ◽  
Yanan Shen ◽  
Wenjing Lu ◽  
Lengqiu Guo ◽  
Min Xiang ◽  
...  

Background: Although the stability of proteins is of significance to maintain protein function for therapeutical applications, this remains a challenge. Herein, a general method of preserving protein stability and function was developed using gelatin films. Method: Enzymes immobilized onto films composed of gelatin and Ethylene Glycol (EG) were developed to study their ability to stabilize proteins. As a model functional protein, β-glucosidase was selected. The tensile properties, microstructure, and crystallization behavior of the gelatin films were assessed. Result: Our results indicated that film configurations can preserve the activity of β-glucosidase under rigorous conditions (75% relative humidity and 37°C for 47 days). In both control films and films containing 1.8 % β-glucosidase, tensile strength increased with increased EG content, whilst the elongation at break increased initially, then decreased over time. The presence of β-glucosidase had a negligible influence on tensile strength and elongation at break. Scanning electron-microscopy (SEM) revealed that with increasing EG content or decreasing enzyme concentrations, a denser microstructure was observed. Conclusion: In conclusion, the dry film is a promising candidate to maintain protein stabilization and handling. The configuration is convenient and cheap, and thus applicable to protein storage and transportation processes in the future.


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