POLYMER ELECTROLYTE BLENDS OF MONO-CARBOXYLIC ACID–MODIFIED EPOXIDIZED NATURAL RUBBER AND POLY(ETHYLENEOXIDE)

2018 ◽  
Vol 91 (1) ◽  
pp. 120-135
Author(s):  
Wan Nurhidayah A. Karim ◽  
Jin Guan Ng ◽  
Chin Han Chan ◽  
Rosiyah Yahya ◽  
Seng Neon Gan

ABSTRACT Natural rubber with 50% of isoprene units epoxidized (ENR50) was treated with excess of mono-carboxylic acids to completely ring open the epoxide groups. The reaction was carried out by heating ENR50 dissolved in toluene with each of acetic and benzoic acid separately at 105 °C. The ring-opening reaction has produced hydroxyl –OH and ester –O-COR groups, leading to an increase in Tg. The products were characterized by Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy, thermal gravimetric analysis, and differential scanning calorimetry. By the solution casting method, each of the modified ENR50s was blended with poly(ethylene oxide) (PEO) in various ratios in toluene, and 2% lithium perchlorate (LiCIO4) was added as the dopant. Results show that the modified ENR and PEO formed incompatible blends. The PEO spherulite growth rate in the blends increased with PEO content. The electrical conductivity was found to increase with the weight fraction of PEO in the blend. At the ratio of 25/75, the acetic acid–modified ENR50/PEO blend exhibits a conductivity value of 3.1 × 10−8 S cm−1. The benzoic acid–modified ENR50/PEO achieved conductivity of 5.8 × 10−7 S cm−1 at the ratio of 30/70. These blends form conducting polymer electrolytes with potential application in batteries.

2012 ◽  
Vol 554-556 ◽  
pp. 126-129 ◽  
Author(s):  
Shun Yin ◽  
Ning Sun ◽  
Chun Yun Feng ◽  
Zhi Mou Wu ◽  
Zhao Hua Xu ◽  
...  

A series of different generation hyperbranched polyurethane(HBPU) was synthesized based on the raw materials of isophorone diisocyanate(IPDI) and diethanolamine(DEOA). Their structure, thermal degradation mechanism and glass transition temperature(Tg) were characterized by fourier transform infrared spectroscopy(FTIR), nuclear magnetic resonance spectroscopy(NMR), thermal gravimetric analysis(TGA) and differential scanning calorimetry(DSC). The results showed that: the yield of each generation HBPU was up to 90%, different generation HBPU had almost the same initial degradation temperature(about at 200°C) and they all had two decomposition platforms; with the increase of generation, Tg increased from 107.2°C to 132.1°C. The gloss and hardness of the HBPU coatings were significantly improved.


2017 ◽  
Vol 36 (10) ◽  
pp. 955-962 ◽  
Author(s):  
Khezrollah Khezri ◽  
Yousef Fazli

AbstractHydrophilic silica aerogel nanoparticles surface was modified with hexamethyldisilazane. Then, the resultant modified nanoparticles were used in random copolymerization of styrene and butyl acrylate via activators generated by electron transfer for atom transfer radical polymerization. Conversion and molecular weight determinations were performed using gas and size exclusion chromatography respectively. Addition of modified nanoparticles by 3 wt% results in a decrease of conversion from 68 to 46 %. Molecular weight of copolymer chains decreases from 12,500 to 7,500 g.mol–1 by addition of 3 wt% modified nanoparticles; however, PDI values increase from 1.1 to 1.4. Proton nuclear magnetic resonance spectroscopy results indicate that the molar ratio of each monomer in the copolymer chains is approximately similar to the initial selected mole ratio of them. Increasing thermal stability of the nanocomposites is demonstrated by thermal gravimetric analysis. Differential scanning calorimetry also shows a decrease in glass transition temperature by increasing modified silica aerogel nanoparticles.


2011 ◽  
Vol 84 (2) ◽  
pp. 166-177 ◽  
Author(s):  
Chengching K. Chiang ◽  
Wenshuang Xie ◽  
Colleen McMahan ◽  
Judit E. Puskas

Abstract Monitoring the growth of in vitro natural rubber was accomplished by high resolution size exclusion chromatography, SEC. Washed rubber particles isolated from H. brasiliensis latex, containing the rubber transferase enzyme, were used to catalyze the polymerization of synthetic isopentenyl pyrophosphate monomer in the presence of farnesyl pyrophosphate initiator. The high-resolution SEC was able to detect the formation of new rubber. Changes in the low molecular weight fraction were also detected. Gravimetric analysis revealed ∼30% mass gain after the in vitro synthesis. The overall gel content was found to be reduced, which further supported the formation of new rubber. This is the first report that utilizes high-resolution SEC to monitor the in vitro NR growth without the use of radiolabeling.


Coatings ◽  
2018 ◽  
Vol 8 (3) ◽  
pp. 88 ◽  
Author(s):  
Jinyue Dai ◽  
Shimin Yang ◽  
Na Teng ◽  
Yuan Liu ◽  
Xiaoqing Liu ◽  
...  

In this work, several bio-based main-chain type benzoxazine oligomers (MCBO) were synthesized from eugenol derivatives via polycondensation reaction with paraformaldehyde and different diamine. Afterwards, their chemical structures were confirmed by Fourier Transform Infrared Spectroscopy (FT-IR) and Nuclear Magnetic Resonance Spectroscopy (1H-NMR). The curing reaction was monitored by Differential Scanning Calorimetry (DSC) and FT-IR. The polybenzoxazine films were prepared via thermal ring-opening reaction of benzoxazine groups without solvent, and their thermodynamic properties, thermal stability, and coating properties were investigated in detail. Results indicated that the cured films exhibited good thermal stability and mechanical properties, showing 10% thermal weight loss (Td10%) temperature as high as 408 °C and modulus at a room temperature of 2100 MPa as well as the glass transition temperature of 123 °C. In addition, the related coatings exhibited high hardness, excellent adhesion, good flexibility, low moisture absorption, and outstanding solvent resistance.


Catalysts ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 822
Author(s):  
Eleftheria Xanthopoulou ◽  
Alexandra Zamboulis ◽  
Zoi Terzopoulou ◽  
Margaritis Kostoglou ◽  
Dimitrios N. Bikiaris ◽  
...  

Over the last few decades, bio-based polymers have attracted considerable attention from both academic and industrial fields regarding the minimization of the environmental impact arising from the excessive use of petrochemically-based polymeric materials. In this context, poly(ethylene vanillate) (PEV), an alipharomatic polyester prepared from 4-(2-hydroxyethoxy)-3-methoxybenzoic acid, a monomer originating from lignin-derived vanillic acid, has shown promising thermal and mechanical properties. Herein, the effects of three different catalysts, namely titanium butoxide (TBT), titanium isopropoxide (TIS), and antimony trioxide (Sb2O3), on the synthesis of PEV via a two-stage melt polycondensation method are investigated. The progress of the reaction is assessed using various complementary techniques, such as intrinsic viscosity measurement (IV), end group analysis (AV), nuclear magnetic resonance spectroscopy (NMR), Fourier-transformed infrared spectroscopy (FTIR), and differential scanning calorimetry (DSC). The thermal stability of the produced polyesters is studied by evolved gas analysis mass spectrometry (EGA-MS). Moreover, as the discoloration in polymers affects their applications, color measurement is performed here. Finally, theoretical kinetic studies are carried out to rationalize the experimental observations.


2016 ◽  
Vol 49 (5) ◽  
pp. 422-439 ◽  
Author(s):  
Supat Moolsin ◽  
Nattawud Saksayamkul ◽  
Adul Na Wichien

The effects of graft copolymers applied as compatibilizers for natural rubber/nitrile rubber (NR/NBR) blends at 50/50 (w/w) on cure characteristics, mechanical properties, thermal properties, oil resistance, and morphology were investigated. The graft copolymers of methyl methacrylate (MMA) onto NR initiated by benzoyl peroxide (NR- g-PMMA<BPO>) and by potassium persulfate (NR- g-PMMA<PPS>) under emulsion polymerization were synthesized and used to compatibilize the blends. The structures of the copolymers were characterized by Fourier transform infrared spectroscopy and proton nuclear magnetic resonance spectroscopy. NR was blended with NBR via a two-roll mill at 70°C under the compatibilizer loading ranging from 0 to 10 parts per hundred of rubber (phr). The results showed that the tensile property and tear strength of the blends increased with the increasing amount of NR- g-PMMA<BPO> as a compatibilizer. Thermal aging determined in terms of tensile properties exhibited the smaller difference between before and after aging in an oven with the increasing compatibilizer loading. The morphology of the compatibilized NR/NBR vulcanizates was investigated by scanning electron microscopy of the tensile fracture surfaces, which exhibited the improvement of interfacial adhesion between the two rubber phases. The thermal properties of compatibilized NR/NBR vulcanizates were reported in terms of a glass transition temperature under differential scanning calorimetry and dynamic mechanical analysis. The incorporation of an appropriate amount of the compatibilizer into the blends apparently improved the oil resistance of NR. Among them, the blend filled with 7.5 phr of NR- g-PMMA<BPO> showed the lowest volume change in IRM 903 oil.


2016 ◽  
Vol 848 ◽  
pp. 3-6 ◽  
Author(s):  
Pornchaloem Naksuwan ◽  
Michal Komárek ◽  
Jana Salačová ◽  
Jiří Militký

Bottles made from poly (ethylene terephthalate) (PET) can be recycled and reused the material to reduce the amount of waste going into landfills. In this study, electrospun fibres from recycled PET were produced by a melt-electrospinning method. The effect of the melting temperature, applied voltage and distance between die and collector on the morphology of the electrospun fibres was investigated. Thermal properties of recycled PET were characterized by a differential scanning calorimetry (DSC) and a thermo gravimetric analysis (TGA). It was observed that recycled PET granules were melted at a temperature of 260, 290 and 310 °C, the melt polymer was electrospun at a high voltage of 38 kV and electrospinning was carried out at a distance of 12 cm. The Recycled PET electrospun had diameters ranging from 45 to 65 µm.


2018 ◽  
Vol 31 (2) ◽  
pp. 211-219 ◽  
Author(s):  
Qiu-xia Wang ◽  
Fu-chen Zhang ◽  
De-zhi Qu ◽  
Yong-ping Bai

In this study, the preparation and properties of poly(ethylene terephthalate-co-2-methyl-1,3-propanediol) copolyester (PEMT) were reported. The PEMT crystallization properties, optical properties, thermal properties, rheological properties, and other properties were characterized by nuclear magnetic resonance (1H NMR), differential scanning calorimetry, thermo gravimetric analysis, ultraviolet visible near-infrared (UV-VIS-NIR) spectroscopy, polarizing microscope crystal culture, X-ray diffraction (XRD), and rheometer. It was proved that the crystallization abilities and crystallization rate of PEMT copolyesters were significantly affected by the content of 2-methyl-1,3-propanediol (MPO) units; the copolyester becomes amorphous when the content of MPO units exceeded 20 mol%. According to the XRD data, the diffraction peaks of PEMT remained unchanged compared with those of poly(ethylene terephthalate). The transmittance of copolyesters displayed a tendency of increasing at first and then declining with the increase in MPO. In addition to the crystallization properties, the transmittance of copolyesters was also affected by the extent of yellowing. When the MPO addition was less than 20 mol%, PEMT can maintain good thermal decomposition performance and processability.


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