scholarly journals A Zn-MOF-Catalyzed Terpolymerization of Propylene Oxide, CO2, and β-butyrolactone

Catalysts ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 393 ◽  
Author(s):  
Sudakar Padmanaban ◽  
Sivanesan Dharmalingam ◽  
Sungho Yoon
Keyword(s):  
Thermal Stability ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Propylene Oxide ◽  
One Pot ◽  
The One ◽  
First Time ◽  
Poly Carbonate ◽  
Thermal Stability Of

The terpolymerization of propylene oxide (PO), CO2, and a lactone is one of the prominent sustainable procedures for synthesizing thermoplastic materials at an industrial scale. Herein, the one-pot terpolymerization of PO, CO2, and β-butyrolactone (BBL) was achieved for the first time using a heterogeneous nano-sized catalyst: zinc glutarate (ZnGA-20). The reactivity of both PO and BBL increased with the CO2 pressure, and the polyester content of the terpolymer poly (carbonate-co-ester) could be tuned by controlling the infeed ratio of PO to BBL. When the polyester content increased, the thermal stability of the polymers increased, whereas the glass transition temperature (Tg) decreased.

Modification of the Mechanical Behavior in the Glass Transition Region of Poly(lactic acid) (PLA) through Catalyzed Reactive Extrusion with Poly(carbonate) (PC)

2015 ◽  
Vol 1119 ◽  
pp. 292-295
Author(s):  
Vu Thanh Phuong ◽  
Maria Beatrice Coltelli ◽  
Irene Anguillesi ◽  
Patrizia Cinelli ◽  
Andrea Lazzeri
Keyword(s):  
Thermal Stability ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Transition Region ◽  
Reactive Extrusion ◽  
Maximum Temperature ◽  
Glass Transition Region ◽  
The One ◽  
Poly Carbonate

In order to improve the thermal stability of PLA based materials it was followed the strategy of blending it with a polymer having a higher glass transition temperature such as poly (carbonate) of bisphenol A (PC) . PLA/PC blends with different compositions were by melt extrusion produced also in the presence of an interchange reaction catalyst, tetrabutylammonium tetraphenylborate (TBATPB) and triacetin. The dynamical mechanical thermal characterization showed an interesting change of the storage modulus behavior in the PLA glass transition region, evident exclusively in the catalyzed blends. In particular, a new peak in the Tan δ trend at a temperature in between the one of PLA and the one of PC was observed only in the blends obtained in the presence of triacetin and TBATPB. The height and maximum temperature of the peak was different after the annealing of samples at 80°C. The data showed an interesting improvement of thermal stability above the PLA glass transition, this was explained keeping into account the formation of PLA-PC copolymer during the reactive extrusion. Furthermore, the glass transition temperature of the copolymer as a function of composition was studied and the obtained trend was discussed by comparing with literature models developed for copolymers.

Nanocomposite Epoxy Resin for SiC Module

2011 ◽  
Vol 2011 (HITEN) ◽  
pp. 000196-000200 ◽  
Author(s):  
Kenji Okamoto ◽  
Yuji Takematsu ◽  
Miyako Hitomi ◽  
Yoshinari Ikeda ◽  
Yoshikazu Takahashi
Keyword(s):  
Thermal Stability ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Epoxy Resin ◽  
Molecular Motion ◽  
Experimental Results ◽  
Power Module ◽  
Operation Temperature ◽  
Thermal Stability Of

There is a demand to improve the thermal stability of epoxy molding resins used in the power module of SiC power chips operating at temperatures of 200°C or more. This paper describes a technique for increasing the thermal stability of the resin by decreasing molecular motion through the addition of nanofiller. The experimental results showed that the glass transition temperature (Tg) of the epoxy resin increased by approximately 30°C when the silica nanofiller was added. The epoxy resin added nanofiller was investigated in order to achieve the operation temperature 200°C of power module.

Thermal Properties of Acrylic Resin Denture Base Material Containing Silver Nanoparticle Synthesized from Aqueous Extract of Boesenbergia rotunda

2018 ◽  
Vol 777 ◽  
pp. 173-177
Author(s):  
Panjaporn Wongwitthayakool ◽  
Matsayapan Pudla
Keyword(s):  
Thermal Stability ◽  
Glass Transition ◽  
Thermal Properties ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Base Material ◽  
Acrylic Resin ◽  
Denture Base ◽  
Acrylic Resins ◽  
Thermal Stability Of

Silver nanoparticles (AgNPs) were synthesized by bioreduction method using aqueous extracts of Boesenbergia rotunda as reducing and stabilizing agents. Ultraviolet-Visible (UV-Vis) spectrophotometer was utilized to monitor the qualitative formation of AgNPs. The UV-Vis spectrum showed that the spherical AgNPs with diameter of 20-40 nm were formed. The antifugal activity of synthesized AgNPs was investigated using Candida albicans, which was found that the synthesized AgNPs could be used as effective growth inhibitors. The influence of the incorporation of prepared AgNPs on thermal properties of the acrylic denture base material was investigated. Glass transition temperature of filled acrylic resins was studied using the dynamic mechanical analyzer (DMA). The temperature sweeps were performed with tension mode. Thermogravimetry analysis (TGA) was used to examine effect of AgNP concentration and thermocycling (1250, 2500, 5000, and 10000 cycles) on thermal stability of AgNP filled acrylic resin denture base materials. Glass transition temperature (Tg) of the acrylic resins slightly increase with increasing AgNP contents. TGA results indicated that AgNP retarded thermal degradation of acrylic resin denture material, and thermocycling did not affect thermal stability of AgNP filled acrylic resin denture material.

Isothermal Crystallization of Zr55Al10Ni5Cu30 Bulk Amorphous Alloy Near the Glass Transition Temperature

2004 ◽  
Vol 449-452 ◽  
pp. 933-936 ◽  
Author(s):  
Zhuang Qi Hu ◽  
Q.S. Zhang ◽  
Hai Feng Zhang ◽  
B.Z. Ding ◽  
Z.M. Rao
Keyword(s):  
Thermal Stability ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Amorphous Alloy ◽  
Amorphous Phase ◽  
Isothermal Crystallization ◽  
Metastable Phases ◽  
Bulk Amorphous Alloy ◽  
Thermal Stability Of

Isothermal crystallization of Zr55Al10Ni5Cu30bulk amorphous alloy near the glass transition temperature has been investigated. The microstructures and thermal stability of the annealed amorphous alloy were examined by HRTEM, XRD and DSC. The amorphous phase in the Zr55Al10Ni5Cu30bulk amorphous alloy crystallized at 420°C through the following processes of amorphous →amorphous with clusters + metastable phases→metastable phases.

Effects of graphene on thermal properties and thermal stability of polycarbonate/graphene nanocomposite

2021 ◽  
pp. 089270572199788
Author(s):  
Md Amir Sohel ◽  
Abhijit Mondal ◽  
P Mohammad Arif ◽  
Sabu Thomas ◽  
Asmita SenGupta
Keyword(s):  
Thermal Stability ◽  
Thermal Decomposition ◽  
Glass Transition ◽  
Thermal Properties ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Multilayer Graphene ◽  
Melt Mixing ◽  
Graphene Nanocomposite ◽  
Thermal Stability Of

Polycarbonate (PC) /graphene nanocomposite was prepared using multilayer graphene (MLG) with loadings of 0.5, 1, and 3 wt% via melt mixing process. Morphological, structural, and thermal properties of the PC/MLG nanocomposites are investigated to look into the influence of MLG on the nanocomposite. A significant increase (∼6.4°C) in glass transition temperature is observed upon the addition of 3 wt% of MLG into the polycarbonate matrix. This increase in glass transition temperature may be due to the interaction between the MLG and polycarbonate polymer matrix. The specific heat capacity of pure PC and PC/MLG nanocomposites varies linearly with temperature below their glass transition. Upon the addition of MLGs, the overall thermal stability of PC/MLG nanocomposites increases with MLG loadings. A maximum increase about 29.23°C in T onset of thermal decomposition is observed in PC/MLG nanocomposite having 3 wt% of MLG loading. The activation energy ( Ea) of thermal decomposition is also calculated by kinetic analysis of thermal decomposition of the PC/MLG nanocomposites using Horowitz–Metzger and Broido’s methods.

Preparation of self-promoted hydroxy-containing phthalonitrile resins by an in situ reaction

RSC Advances ◽  
2015 ◽  
Vol 5 (127) ◽  
pp. 105038-105046 ◽  
Author(s):  
Jianbo Wang ◽  
Jianghuai Hu ◽  
Ke Zeng ◽  
Gang Yang
Keyword(s):  
Thermal Stability ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Hydroxy Group ◽  
High Modulus ◽  
High Glass Transition Temperature ◽  
One Pot ◽  
In Situ Reaction

The in situ reaction of a hydroxy group with a phthalonitrile system was carried out in a one-pot reaction and the prepared polymers showed outstanding thermal stability, a high modulus and a high glass transition temperature.

scholarly journals Synthesis of Fe75Si20-xB5Mx (M=Ti, Ta or Zr) Powders by Wet Mechanical Milling

2015 ◽  
Vol 13 ◽  
pp. 54-58
Author(s):  
Horea Florin Chicinaş ◽  
Bogdan Viorel Neamţu ◽  
Traian Florin Marinca ◽  
Ionel Chicinaş
Keyword(s):  
Thermal Stability ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Transition Metals ◽  
Mechanical Alloying ◽  
Crystallization Temperature ◽  
Mechanical Milling ◽  
Thermal Stability Of

Amorphous Fe75Si20-xB5Mxpowders with M= Ti, Ta or Zr andx= 0 and 5 were synthesized by wet mechanical alloying, using benzene as a surfactant. The thermal stability of the Fe-Si-B alloy increases by introducing transition metals. The replacement of 5% Si with Ti, Ta or Zr leads to an increase of the crystallization temperature. It was found that the replacement of 5% Si with Zr increases the crystallization temperature with 115 °C, and also reveals a glass transition temperature around 580 °C.

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