Epitaxial nucleation, modulated structure of molecular aggregation, and enhanced thermal degradation temperature of poly(ethylene adipate): Effects of the naturally occurring uracil as a nucleator

2021 ◽  
Author(s):  
Yubin Yang ◽  
Zhe Zhu ◽  
Zhanghua Xie ◽  
Fude Liu ◽  
Jing Yin ◽  
...  
Keyword(s):  
Thermal Degradation ◽  
Molecular Aggregation ◽  
Modulated Structure ◽  
Degradation Temperature ◽  
Naturally Occurring ◽  
Poly Ethylene ◽  
Thermal Degradation Temperature

scholarly journals Thermogravimetric analysis-based characterization of suitable biomass for alkaline peroxide treatment to obtain cellulose and fermentable sugars

BioResources ◽  
2020 ◽  
Vol 15 (3) ◽  
pp. 6217-6229
Author(s):  
Akihiro Hideno
Keyword(s):  
Thermogravimetric Analysis ◽  
Thermal Degradation ◽  
Rice Straw ◽  
Lignin Content ◽  
Cellulose Microfibrils ◽  
Crystalline Cellulose ◽  
Japanese Cypress ◽  
Alkaline Peroxide ◽  
Degradation Temperature ◽  
Thermal Degradation Temperature

To characterize a suitable biomass for alkaline peroxide treatment, four types of lignocellulosic biomass (rice straw, two Miscanthus spp., and Japanese cypress) were characterized using thermogravimetric analysis. Before the alkaline peroxide treatment, rice straw had the lowest initial thermal degradation temperature and Japanese cypress had the highest. After alkaline peroxide treatment, this trend was reversed, such that the highest initial thermal degradation temperature was for alkaline-peroxide treated rice straw. Hemicellulose and lignin content significantly affected the thermal degradation behavior and alkaline peroxide treatment efficiency. Among the four lignocelluloses, raw rice straw exhibited the highest reducing capability, whereas the treated rice straw exhibited the lowest reducing capability. Surface morphology and crystallinity indicated that when the rice straw was subjected to AP treatment at room temperature for 10 min, crystalline cellulose microfibrils were exposed and concentrated on the surface. Thus, among the samples tested, rice straw was found to be the most suitable biomass for alkaline peroxide treatment.

Impact of metal cations on the thermal, mechanical, and rheological properties of telechelic sulfonated polyetherimides

2020 ◽  
Vol 11 (2) ◽  
pp. 393-400 ◽  
Author(s):  
Ke Cao ◽  
Joel M. Serrano ◽  
Tianyu Liu ◽  
Benjamin J. Stovall ◽  
Zhen Xu ◽  
...  
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Thermal Degradation ◽  
Rheological Properties ◽  
Metal Cation ◽  
Complex Viscosity ◽  
Degradation Temperature ◽  
Cation Size ◽  
Thermal Degradation Temperature

The glass transition temperature, thermal degradation temperature, and complex viscosity of metal sulfonated polyetherimides decrease with an increase in metal cation size.

scholarly journals Influence of Starch Content on the Thermal and Viscoelastic Properties of Syndiotactic Polypropylene/Starch Composites

2021 ◽  
Vol 11 (3) ◽  
pp. 7228-7232
Author(s):  
N. Ahmad ◽  
F. Ahmad ◽  
I. Alenezi
Keyword(s):  
Melting Point ◽  
Thermal Degradation ◽  
Starch Content ◽  
Thermal Characterization ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Syndiotactic Polypropylene ◽  
Degradation Temperature ◽  
Expansion System ◽  
Thermal Degradation Temperature

In this study, syndiotactic Polypropylene/Starch (sPP/starch) composites were prepared using a solution mixing technique. The thermal characterization was performed using Differential Scanning Calorimetry (DSC), and the melting point was measured for all polymer composites. The thermal degradation temperature was measured using thermal gravimetric analysis. The viscoelastic measurements were performed using the Atomic Rheometric Expansion System (ARES). Both melting point and thermal degradation temperatures were found to decrease with increasing starch content. Moreover, the elastic modulus was found to decrease when the starch content increased.

scholarly journals Synthesis of a New Phosphorus/Nitrogen Durable Flame Retardant for Cotton Fabrics

2021 ◽  
Author(s):  
Jinfeng Li ◽  
Wei Jiang ◽  
Maolin Liu
Keyword(s):  
Thermal Degradation ◽  
Phosphoric Acid ◽  
Heat Release ◽  
Flame Retardant ◽  
Cotton Fiber ◽  
Cotton Fabrics ◽  
Hydroxyl Group ◽  
Limiting Oxygen Index ◽  
Degradation Temperature ◽  
Thermal Degradation Temperature

Abstract Phosphorus/nitrogen flame retardant ammonium three phosphoric acid glycerol ester (FR) with reactive -P-O−NH4+ groups was synthesized from glycerol, phosphoric acid and urea. At high temperature, the -P-O−NH4+ group in FR is decomposed into -P-O−H+ group. Under the action of catalyst dicyandiamide, -P-O−H+ forms phosphonic anhydride. Phosphonic anhydride can dehydrate and condense with the hydroxyl group on the 6-position carbon atom in the glucose ring of cotton fiber, forming a firm P-O-C bond, thus fixing FR molecule firmlyon cotton fiber. XRD suggested that the finishing process only slightly affected the cotton fiber structure and the surface morphology, elemental composition of char residues in cotton fabrics were tested by scanning electron microscope (SEM) and energy dispersive spectrometer (EDS). Confirmed that FR was grafted well with slight damage to the cotton structure. When the treated cotton with 25.3% weight gain(WG) in FR, the treated cotton has self extinguishing property and passed UL-94 vertical burning V-0 classification, the limiting oxygen index (LOI) was improved from 17.0–40.5%, and the LOI can still reach 30.9% after 50 laundering cycles, the cone calorimetry(CONE) analysis indicated that the peak heat release rate (PHRR) of the treated cotton was reduced from 190.3 kW/m2 to 17.9 kW/m2, and the total heat release (THR) was reduced from 2.8 MJ/m2 to 1.8 MJ/m2, The thermogravimetric(TG) and Differential scanning calorimeter (DSC) showed that the addition of FR inhibited the initial thermal degradation temperature of the treated cotton under heating conditions, and TG showed that the initial thermal degradation temperature of treated cotton in nitrogen and air was 225.9 ℃ and 221.8 ℃, respectively, which was lower than that of untreated cotton. The mechanical properties are in the usable range, which showed that treated cotton have excellent flame retardancy, durability and good flexibility.

Electrospun Nanofibres of PLA/PANI and PLA/P (ANI-co-m-ABA): Thermal Studies

2011 ◽  
Vol 700 ◽  
pp. 137-140 ◽  
Author(s):  
Norizah Abdul Rahman ◽  
Allan J. Easteal ◽  
Jadranka Travas-Sejdic ◽  
Allan J. Easteal
Keyword(s):  
Lactic Acid ◽  
Thermal Degradation ◽  
Thermal Effects ◽  
Thermal Studies ◽  
Poly Lactic Acid ◽  
Aminobenzoic Acid ◽  
Degradation Temperature ◽  
Electrospun Nanofibres ◽  
Poly Aniline ◽  
Thermal Degradation Temperature

Composite nanofibres of poly (lactic acid) (PLA) with polyaniline (PANI) or poly (aniline-co-m-aminobenzoic acid) (P (ANI-co-m-ABA)) were prepared by electrospinning. Thermal effects on the properties of the composite nanofibres were studied by means of DSC and TGA. TGA results show that the onset thermal degradation temperature of the composite fibres was slightly higher than that of pure PLA. The degree of the crystallinity of the nanofibres was determined from DSC data and compared to film with the same composition.

scholarly journals Thermal properties of MECDP copolyesters

2012 ◽  
Vol 16 (5) ◽  
pp. 1456-1459 ◽  
Author(s):  
Ming-Liang Zhao ◽  
Yuan Liu ◽  
Fa-Xue Li ◽  
Xue-Li Wang ◽  
Yu Gao ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Thermal Degradation ◽  
Ethylene Glycol ◽  
Poly Ethylene Glycol ◽  
Scanning Calorimetry ◽  
Degradation Temperature ◽  
Poly Ethylene Terephthalate ◽  
Oxygen Condition ◽  
Poly Ethylene ◽  
Temperature Melting

MECDP copolyesters based on poly(ethylene terephthalate) were prepared with sodium-5-sulfo-bis-(hydroxyethyl)-isophthalate and poly(ethylene glycol) units as modifiers. Thermal properties of these copolyesters were characterized by differential scanning calorimetry and thermal gravity analyzer. Experimental results indicated that glass transition temperature, melting temperature and thermal degradation temperature reduced with increasing the poly(ethylene glycol) content. The incorporation of poly(ethylene glycol) increased the flexibility and irregularity of molecular chains which led to lower crystallinity, and bought more ether bonds into molecular chains. Besides, the thermal degradation under oxygen condition happened easily compared to that under nitrogen condition.

scholarly journals Synthesis of a New Phosphorus/Nitrogen Durable Flame Retardant for Cotton Fabrics

2021 ◽  
Author(s):  
Jinfeng Li ◽  
Wei Jiang ◽  
Maolin Liu
Keyword(s):  
Thermal Degradation ◽  
Phosphoric Acid ◽  
Heat Release ◽  
Flame Retardant ◽  
Cotton Fiber ◽  
Cotton Fabrics ◽  
Hydroxyl Group ◽  
Limiting Oxygen Index ◽  
Degradation Temperature ◽  
Thermal Degradation Temperature

Abstract Phosphorus/nitrogen flame retardant ammonium three phosphoric acid glycerol ester (FR) with reactive -P-O−NH4+ groups was synthesized from glycerol, phosphoric acid and urea. At high temperature, the -P-O−NH4+ group in FR is decomposed into -P-O−H+ group. Under the action of catalyst dicyandiamide, -P-O−H+ forms phosphonic anhydride. Phosphonic anhydride can dehydrate and condense with the hydroxyl group on the 6-position carbon atom in the glucose ring of cotton fiber, forming a firm P-O-C bond, thus fixing FR molecule firmlyon cotton fiber. XRD suggested that the finishing process only slightly affected the cotton fiber structure and the surface morphology, elemental composition of char residue in cotton fabrics were tested by scanning electron microscope (SEM) and energy dispersive spectrometer (EDS). Confirmed that FR was grafted well with slight damage to the cotton structure. When the treated cotton with 25.3% weight gain(WG) in FR, the treated cotton has self extinguishing property and passed UL-94 vertical burning V-0 classification, the limiting oxygen index (LOI) was improved from 17.0–40.5%, and the LOI can still reach 30.9% after 50 laundering cycles, the cone calorimetry(CONE) analysis indicated that the peak heat release rate (PHRR) of the treated cotton was reduced from 190.3 kW/m2 to 17.9 kW/m2, and the total heat release (THR) was reduced from 2.8 MJ/m2 to 1.8 MJ/m2, The thermogravimetric(TG) and Differential scanning calorimeter (DSC) showed that the addition of FR inhibited the initial thermal degradation temperature of the treated cotton under heating conditions, and TG showed that the initial thermal degradation temperature of treated cotton in nitrogen and air was 225.9 ℃ and 221.8 ℃, respectively, which was lower than that of untreated cotton. The mechanical properties are in the usable range, which showed that treated cotton had excellent flame retardancy, durability and good flexibility.

UV Curable Organic-Inorganic Hybrid Materials

2000 ◽  
Vol 628 ◽  
Author(s):  
Guang-Way Jang ◽  
Ren-Jye Wu ◽  
Yuung-Ching Sheen ◽  
Ya-Hui Lin ◽  
Chi-Jung Chang
Keyword(s):  
Hybrid Materials ◽  
Colloidal Silica ◽  
Sol Gel ◽  
Solution Ph ◽  
Uv Curable ◽  
Inorganic Hybrid ◽  
Degradation Temperature ◽  
Sol Gel Process ◽  
The Stability ◽  
Thermal Degradation Temperature

This work successfully prepared an UV curable organic-inorganic hybrid material consisting of organic modified colloidal silica. Applications of UV curable organic-inorganic hybrid materials include abrasion resistant coatings, photo-patternable thin films and waveguides. Colloidal silica containing reactive functional groups were also prepared by reacting organic silane and tetraethyl orthosilicate (TEOS) using sol-gel process. In addition, the efficiency of grafting organic moiety onto silica nanoparticles was investigated by applying TGA and FTIR techniques. Experimental results indicated a strong interdependence between surface modification efficiency and solution pH. Acrylate-SiO2 hybrid formation could result in a shifting of thermal degradation temperature of organic component from about 200°C to near 400°C. In addition, the stability of organic modified colloidal silica in UV curable formula and the physical properties of resulting coatings were discussed. Furthermore, the morphology of organic modified colloidal silica was investigated by performing TEM and SEM studies‥

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