scholarly journals Towards High-performance Materials Based on Carbohydrate-Derived Polyamide Blends

Polymers ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 413 ◽  
Author(s):  
Aleksandra Wróblewska ◽  
Nils Leoné ◽  
Stefaan De Wildeman ◽  
Katrien Bernaerts

A bio-derived monomer called 2,3:4,5-di-O-isopropylidene-galactarate acid/ester (GalXMe) has great potential in polymer production. The unique properties of this molecule, such as its rigidity and bulkiness, contribute to the good thermal properties and appealing transparency of the material. The main problem, however, is that like other biobased materials, the polymers derived thereof are very brittle. In this study, we report on the melt blending of GalXMe polyamides (PAs) with different commercial PA grades using extrusion as well as blend characterization. Biobased PA blends showed limited to no miscibility with other polyamides. However, their incorporation resulted in strong materials with high Young moduli. The increase in modulus of the prepared GalXMe blends with commercial PAs ranged from up to 75% for blends with aliphatic polyamide composed of 1,6-diaminohexane and 1,12-dodecanedioic acid PA(6,12) to up to 82% for blends with cycloaliphatic polyamide composed of 4,4′-methylenebis(cyclohexylamine) and 1,12-dodecanedioic acid PA(PACM,12). Investigation into the mechanism of blending revealed that for some polyamides a transamidation reaction improved the blend compatibility. The thermal stability of the biobased PAs depended on which diamine was used. Polymers with aliphatic/aromatic or alicyclic diamines showed no degradation, whereas with fully aromatic diamines such as p-phenylenediamine, some degradation processes were observed under extrusion conditions (260/270 °C).

2011 ◽  
Vol 79 ◽  
pp. 282-287 ◽  
Author(s):  
Yi Chen ◽  
Guang Sheng Zeng ◽  
Ping Jiang ◽  
Wei Lu ◽  
Wei Long Huang

EVA was added into PC/PLA blends as a modifier for improving the impact strength of blends, and meanwhile the thermal properties and rheological properties of blends should also be influenced. PC/PLA/EVA blends were prepared by melt blending and the catalyst DBTO was added into the blends in blending process to catalyze the transesterification of PC and EVA for improving the compatibility of blends. The effects of blend composition and transesterification on the thermal and rheological properties of blends were investigated. The results showed that the addition of EVA could improve the crystallinity of PLA in PC/PLA/EVA blends but had little influence on the thermal stability of blends,and the transesterification was beneficial to both the crystallization of PLA and thermal stability of blends. The addition of EVA and the transesterification of PC and EVA increased the apparent viscosity of blends, while the apparent viscosity of blends decreased drastically and the pseudo-plasticity characteristic of blend melts was weakened obviously with increasing PLA content and rising temperature.


Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 728
Author(s):  
Sangyoon Park ◽  
Sarinthip Thanakkasaranee ◽  
Hojun Shin ◽  
Youngsoo Lee ◽  
Guman Tak ◽  
...  

To improve the dimensional thermal stability of polyethylene terephthalate (PET), a poly(ethylene glycol 1,4-cyclohexane dimethylene (CHDM) isosorbide (ISB) terephthalate) (PEICT) known as ECOZEN®T110 (EZT) was introduced into PET using a melt blending technique. The miscibility, morphology, and thermal properties of the PET/EZT samples were investigated. The introduction of amorphous EZT into semi-crystalline PET increased the glass transition temperature (Tg) but decreased the crystallinity, which could be related to the transesterification reaction. By adding EZT contents up to 20%, the PET/EZT samples showed a single Tg, which indicated the miscibility between PET and EZT. However, two Tg values were observed in the PET/EZT samples with higher EZT contents (30–70%), indicating partial miscibility. This may have been due to the slightly different rheological and thermodynamic parameters that were affected by a higher ratio of bulky (rigid ISB and ductile CHDM) groups in EZT. However, the heat distortion temperature of the PET/EZT samples remarkably increased, which indicated that the dimensional stability was truly enhanced. Although the crystallinity of the PET/EZT samples decreased with increasing EZT content, the tensile strength and Young’s modulus decreased slightly. Based on these results, the as-prepared PET/EZT samples with high dimensional stability can be used as a high-temperature polymeric material in various applications.


2014 ◽  
Vol 887-888 ◽  
pp. 49-52 ◽  
Author(s):  
Noureddine Ramdani ◽  
Jun Wang ◽  
Wen Bin Liu

In this work, typical polybenzoxazine, as new class of phenolic resin, has been used as a matrix for preparing a series of high performance hybrid materials using various amounts of titanium carbide (TiC) ranging between 0-10 wt% as fillers, via a solution blending technique. The thermal properties of bisphenol A-aniline base benzoxazine monomers (BA-a) and TiC mixtures have been studied by differential scanning calorimetry (DSC). The thermal stability of their cured hybrids has been tested by means of thermogravimetric analysis (TGA). The result showed that the glass transition temperature of the prepared composites increased with increasing the amount of TiC to reach a higher value at 194°C. Also, the incorporation of TiC nanoparticles has considerably improved the thermal stability of the hybrids including the char yield which increase by 50 % at 10 wt% TiC content.


2011 ◽  
Vol 2011 (17) ◽  
pp. 2733-2737 ◽  
Author(s):  
Hao Yin ◽  
Birgitte L. Pedersen ◽  
Bo B. Iversen

2017 ◽  
Vol 898 ◽  
pp. 2181-2186
Author(s):  
Jing Li ◽  
Jun Rong Yu ◽  
Jing Zhu ◽  
Yan Wang ◽  
Zu Ming Hu ◽  
...  

Solution blow spinning (SBS) is an innovative nanofiber fabricating method with high productivity. 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA) / p-phenylenediamine (PDA) / 4,4'-oxydianiline (ODA) co-polyimide nanofiber membrane was efficiently produced by SBS followed by imidization from precursor polyamic acid (PAA) nanofiber membrane in the paper. The morphologies and structures of the obtained PAA and PI nanofiber membrane were examined by SEM and FT-IR. The effect of thermal imidization temperature on the tensile property was investigated. The thermal stability of polyimide nanofiber membrane was also characterized by TGA.


Author(s):  
Hongtao Zhang ◽  
Youjing Zhao ◽  
Jingli Li ◽  
Lijie Shi ◽  
Min Wang

AbstractThis paper focuses on thermal stability of molten salts, operating temperature range and latent heat of molten salts at a high temperature. In this experiment, multi-component molten salts (purified Solar Salt) composed of purified NaNO


2018 ◽  
Vol 6 (35) ◽  
pp. 17171-17176 ◽  
Author(s):  
Lasse Rabøl Jørgensen ◽  
Jiawei Zhang ◽  
Christian Bonar Zeuthen ◽  
Bo Brummerstedt Iversen

The thermal stability of the high performance n-type Te-doped Mg3Sb1.5Bi0.5 system is investigated.


Polymers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 644 ◽  
Author(s):  
Farimah Tikhani ◽  
Shahab Moghari ◽  
Maryam Jouyandeh ◽  
Fouad Laoutid ◽  
Henri Vahabi ◽  
...  

For the first time, nano-scale aluminum hypophosphite (AlPO2) was simply obtained in a two-step milling process and applied in preparation of epoxy nanocomposites varying concentration (0.1, 0.3, and 0.5 wt.% based on resin weight). Studying the cure kinetics and thermal stability of these nanocomposites would pave the way toward the design of high-performance nanocomposites for special applications. Scanning electron microscopy (SEM) and transmittance electron microscopy (TEM) revealed AlPO2 particles having domains less than 60 nm with high potential for agglomeration. Excellent (at heating rate of 5 °C/min) and Good (at heating rates of 10, 15 and 20 °C/min) cure states were detected for nanocomposites under nonisothermal differential scanning calorimetry (DSC). While the dimensionless curing temperature interval (ΔT*) was almost equal for epoxy/AlPO2 nanocomposites, dimensionless heat release (ΔH*) changed by densification of polymeric network. Quantitative cure analysis based on isoconversional Friedman and Kissinger methods gave rise to the kinetic parameters such as activation energy and the order of reaction as well as frequency factor. Variation of glass transition temperature (Tg) was monitored to explain the molecular interaction in the system, where Tg increased from 73.2 °C for neat epoxy to just 79.5 °C for the system containing 0.1 wt.% AlPO2. Moreover, thermogravimetric analysis (TGA) showed that nanocomposites were thermally stable.


2020 ◽  
Vol 990 ◽  
pp. 106-110
Author(s):  
Mohd Zulkifli Mohamad Noor ◽  
Mohamad Anas Mohd Azmi ◽  
Mohd Shaiful Zaidi Mad Desa ◽  
Mohd Bijarimi Mat Piah ◽  
Azizan Ramli

Neoprene reinforced polymer has become an attraction in current research and development of new material blend. In this invention, neoprene was chosen to be enhance to polyurethane because of their superior properties that possess extraordinary mechanical, electrical, optical and thermal properties on prosthetic foot. In this research, polyurethane was chosen due to good rigidity, easy processing and low cost. The reinforcement polyurethane with neoprene is expected to improve the properties of polyurethane. The objective of this research was conducted to investigate the effect of neoprene contents on thermal properties of polyurethane reinforced neoprene on prosthetic foot. The effect of neoprene on thermal properties neoprene reinforced polyurethane was analysed in term of its thermal stability by thermal gravimetric analysis (TGA). Moreover, the visual of small topographic details on the surface of polyurethane/neoprene blends will be examined by scanning electron microscope (SEM). Based on result, the thermal properties show the great enhancement at high neoprene contents which is 1.0wt%. The thermal stability of polyurethane reinforced neoprene improves when the temperature where decomposition starts to occurs are higher than decomposition temperature of pure polyurethane. Then, thermal conductivity of polyurethane shows the great improvement after the addition of neoprene. Lastly, the smooth surface and visible of sheets pattern on surface represent the present of neoprene disperse into polymer that enhance brittleness. Thus, the presence of neoprene has clearly enhanced the thermal stability of the polyurethane. Table 1 shows formulation of neoprene and polyurethane.


2011 ◽  
Vol 415-417 ◽  
pp. 261-264
Author(s):  
Yuan Ren ◽  
Zheng Xi ◽  
Wen Jun Gan ◽  
Liang Zhang ◽  
Jing Zhang ◽  
...  

A siloxane-containing dianhydride, succinic anhydride terminated polydimethylsiloxane (DMS-Z21) was selected to cure diglycidyl ether of bisphenol-A based epoxy resin (DGEBA). The cure kinetics and thermal properties were investigated by nonisothermal and isothermal differential scanning calorimetry (DSC) and thermogravimetric analyses (TGA), respectively. The activation energy (Ea) of the curing reaction was obtained based on the methods of Kissinger and isothermal measurements. The results of the thermogravimetric analyses of the DGEBA/DMS-Z21 system showed that the thermal stability of the DGEBA/DMS-Z21 system was slightly higher than the DGEBA/MeTHPA system.


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