CO2 -philic polyether-block -amide/glycerol triacetate blend membranes: gas-permeation performance, thermal stability, and storage stability

2019 ◽  
Vol 136 (23) ◽  
pp. 47620 ◽  
Author(s):  
Shichao Feng ◽  
Jizhong Ren ◽  
Dan Zhao ◽  
Hui Li ◽  
Kaisheng Hua ◽  
...  
Author(s):  
Hayun Hayun ◽  
Annisa Zahra ◽  
Hidayatul Lutfika

The antioxidants effect of two aminomethyl derivatives of 2-methoxyphenol: 4,6-di[(morpholin-4-yl)methyl]-2-methoxyphenol (DMMMP) and 5-[(pyrrolidin-1-yl)methyl]vanillic acid (PMVA) on enhancing thermal and oxidative storage stability of coconut oil was performed using tert-butylhydroxyquinone (TBHQ) as a comparative standard. The efficacy on thermal stability test was carried out by heating at 180 oC for 1, 3, and 6 hours, while the efficacy on the storage stability test was performed using an accelerated method by heating at 60oC for 5 weeks. The concentrations for MDMMP was 200, 350, and 500 ppm; for PMVA was 200, 275, and 350 ppm; and for TBHQ was 200 ppm. Free fatty acid (FFA) level, peroxide value (PV), and p-anisidine value (p-AV) were used as parameters to assess the level of oxidative stability of coconut oil. The results showed that the addition of DMMMP 200, 350, and 500 ppm, and PMVA 200 and 275 ppm did not inhibit FFA, peroxide, and aldehyde formation. In thermal stability study, PMVA (350 ppm) could inhibit the free fatty acid release, and formation of secondary oxidation products compounds on thermal stability comparable to TBHQ (200 ppm) addition, but only TBHQ that could inhibit peroxide formation for 6 h. In storage stability, DMMMP (all concentration) could not delay the fatty acid release, while PMVA (all concentration) and TBHQ (200 ppm) delayed that for 2 and 5 weeks, respectively. DMMMP (all concentration) delayed peroxide formation for 2 weeks, while PMVA (all concentration) and TBHQ (200 ppm) delayed peroxide formation for 5 weeks. All compounds only delay the formation of secondary oxidation products for 1 week. In conclusion, the efficacy of PMVA as an antioxidant against thermal and storage oxidative stability of coconut oil is higher than DMMMP but lower than TBHQ.


Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1397
Author(s):  
Nappaphan Kunanusont ◽  
Boonchai Sangpetngam ◽  
Anongnat Somwangthanaroj

Plastic waste has been incorporated with asphalt to improve the physical properties of asphalt and alleviate the increasing trend of plastic waste being introduced into the environment. However, plastic waste comes in different types such as thermoplastic or thermoset, which results in varied properties of polymer modified asphalt (PMA). In this work, four thermoplastic vulcanizates (TPVs) were prepared using different peroxide concentrations to produce four formulations of gel content (with varying extent of crosslinked part) in order to imitate the variation of plastic waste. All four TPVs were then mixed with asphalt at 5 wt% thus producing four formulations of PMA, which went through physical, rheological, and storage stability assessments. PMA with higher gel content possessed lower penetration and higher softening temperature, indicating physically harder appearance of PMA. Superpave parameters remained unchanged among different gel content PMA at temperatures of 64, 70, and 76 °C. PMA with any level of gel content had lower Brookfield viscosity than PMA without gel content at a temperature of 135 °C. Higher gel content resulted in shorter storage stability measured with greater different softening temperatures between top and bottom layers of PMA after 5 days of 163 °C storage. This study shows that asphalt with thermoset plastic waste is harder and easier to pave, thus making the non-recycling thermoset plastic waste more useful and friendly to the environment.


Proceedings ◽  
2020 ◽  
Vol 70 (1) ◽  
pp. 47
Author(s):  
Julius Rami ◽  
Caroline Dumler ◽  
Nadine Weber ◽  
Michael Rychlik ◽  
Gabriele Netzel ◽  
...  

Folate (Vitamin B9) is critical for a range of biological functions in adults and children, including DNA, protein and neurotransmitter synthesis. It is also essential for the healthy development of the fetus in early pregnancy and for the prevention of neural tube defects, such as spina bifida. Strawberries are considered a tasty and healthy fruit consumed all over the world and may potentially be an important dietary source of natural folates. However, the relative importance of strawberry as a dietary source will depend on the total folate concentration, vitamer profile, storage stability and bioavailability to humans. Red Rhapsody, an important commercial strawberry cultivar in Australia, was screened for its folate content and storage stability by stable isotope dilution assay (SIDA). Total folate content ranged from 90–118 μg/100 g fresh weight (fw), which was well above the value in the Australian Food Composition Database (39 μg/100 g fw). 5-Methyltetrahydrofolate, the biologically active form in humans, was the principal vitamer present. Furthermore, folate remained relatively stable during refrigerated (4 °C) storage (loss of only 28% after 14 days of storage). This information is relevant for consumers since the inherent perishability of strawberry fruit makes refrigerated storage common practice in Australian households.


Author(s):  
Cindy T. Sepúlveda ◽  
Ailén Alemán ◽  
José E. Zapata ◽  
M. Pilar Montero ◽  
M. Carmen Gómez-Guillén

LWT ◽  
2021 ◽  
pp. 111463
Author(s):  
Tingting Hong ◽  
Qiyan Zhao ◽  
Dan Xu ◽  
Yirong Yuan ◽  
Yue Ma ◽  
...  

2021 ◽  
Vol 350 ◽  
pp. 129249
Author(s):  
Qais Ali Al-Maqtari ◽  
Abduljalil D.S. Ghaleb ◽  
Amer Ali Mahdi ◽  
Waleed Al-Ansi ◽  
Abeer Essam Noman ◽  
...  

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