scholarly journals The Influence of Substituents in Phosphazene Catalyst-Flame Retardant on the Thermochemistry of Benzoxazine Curing

Polymers ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 3111
Author(s):  
Natalia V. Bornosuz ◽  
Roman F. Korotkov ◽  
Alexander A. Kolenchenko ◽  
Alexey V. Shapagin ◽  
Alexey V. Orlov ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Catalytic Activity ◽  
Glass Transition ◽  
Thermal Properties ◽  
Transition Temperature ◽  
Curing Process ◽  
Flame Resistance ◽  
Dispersion Phase ◽  
Thermal Stability Of ◽  
Influence Of Substituents

This work is devoted to the influence of phosphazene modifiers with different substituents on the curing process, thermal properties and flammability of benzoxazine resin. Novel catalysts with m-toluidine substituents were introduced. The catalytic activity of studied phosphazene compounds decreased in the row: hexachlorocyclotriphosphazene (HCP) > tetra m-toluidine substituted phosphazene PN-mt (4) > hexa m-toluidine substituted phosphazene PN-mt (6) > hexaphenoxycyclotriphosphazene (HPP), where HPP is totally inactive. Two types of catalysis: basic and acid were proposed. A brief study of resulting properties of polybenzoxazines was presented. The addition of any studied modifier caused the decrease of glass transition temperature and thermal stability of polymers. The morphology of cured compositions was characterized by matrix-dispersion phase structure. All phosphazene containing polybenzoxazines demonstrated the improved flame resistance.

Synthesis and characterization of novel benzoxazines containing nitrile and allyl groups and their polymers

e-Polymers ◽  
2010 ◽  
Vol 10 (1) ◽  
Author(s):  
Hongchun Zhang ◽  
Zaijun Lu
Keyword(s):  
Thermal Stability ◽  
Glass Transition ◽  
Thermal Properties ◽  
Transition Temperature ◽  
Ring Opening ◽  
Synthesis And Characterization ◽  
Curing Process ◽  
Oxazine Ring ◽  
Thermal Stability Of

AbstractA p-cyanophenol and allylamine based benzoxazine has been synthesized and characterized. This benzoxazine has nitrile and allyl functionalities that can polymerize, resulting in a highly crosslinked material. The DSC spectra of novel benzoxazine monomer reveal that incorporation of the nitrile and allyl group greatly decreases the ring-opening temperature of oxazine rings (140°C). The IR spectra of curing process indicate that the polymerization of oxazine ring accompany with the curing reaction of allyl and nitrile groups. Benzoxazine monomers with one or none of the two functionalities were also prepared to study structure effect on thermal properties of resulted polymer. The comparison of results confirms that introducing the two functionalities improved glass transition temperature (238 °C), thermal stability of polybenzoxazine (T5%=340 °C), and char yield (57%).

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.

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.

Novel Copolymers of N-[(4-bromo-3,5- difluorine) phenyl] acryl- amide with Methyl Methacrylate: Synthesis, Characterization and Thermal Properties

2013 ◽  
Vol 750-752 ◽  
pp. 1125-1129
Author(s):  
Xin Ding Yao ◽  
Rui Na Fang ◽  
Hong Jian Pang ◽  
Zong Wu Wang ◽  
Guo Ji Liu
Keyword(s):  
Thermal Stability ◽  
Glass Transition ◽  
Thermal Properties ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Thermogravimetric Analysis ◽  
Methyl Methacrylate ◽  
1H Nmr ◽  
Nmr Spectra ◽  
Thermal Stability Of

Copolymers of N-[(4-bromo-3,5-difluorine) phenyacrylamide (BDPA), with methyl methacrylate (MMA) were synthesized in N,N-Dimethylformamide at 75±1°C using 2,2-azobisisobutyronitrile (AIBN) as an initiator with different monomer-to-monomer ratios in the feed. The copolymers were characterized by FTIR and 1H NMR spectra. The glass transition temperature of the copolymers decreases with increase in BDPA content. The thermogravimetric analysis of the polymers showed that the thermal stability of the copolymer decreases with BDPA content.

Study of thermal behavior of poly (lactic) acid composites with electron beam irradiated luffa fiber

2020 ◽  
pp. 2150009
Author(s):  
S. Patra ◽  
K. L. Mohanta ◽  
C. Parida
Keyword(s):  
Thermal Stability ◽  
Electron Beam ◽  
Lactic Acid ◽  
Glass Transition ◽  
Thermal Properties ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Irradiation Dose ◽  
Poly Lactic Acid ◽  
Thermal Stability Of

Modification of surface of natural fibers by high energy electron beam irradiation (6 MeV) is a process for enhancing the adhesion between fiber and matrix. Composites reinforced with natural fiber have gained a prominent place in the field of research and innovation due to the advantages such as low cost, light weight and environment friendly factors. We have studied the thermal properties such as thermal degradation and crystallinity behavior of biodegradable composites using biodegradable polymer poly (lactic) acid (PLA) and fiber of luffa cylindrica (LC) fabricated by using injection molding technique. First, reinforcement LC fibers are irradiated with electron beam of 0.5, 1.0, 2.0, 4.0 and 10.0 Gy using 6 MeV linear accelerator at room temperature in presence of air. The thermal properties like glass transition temperature [Formula: see text], cold crystallization temperature [Formula: see text], melting peak temperature [Formula: see text] and thermal stability of the composites are studied using differential scanning calorimetry (DSC) in the temperature range from 30[Formula: see text]C to 250[Formula: see text]C and thermogravimetric analysis (TGA) in temperature range from 20[Formula: see text]C to 700[Formula: see text]C. The variation of these properties in response to the irradiation dose is analyzed in detail. It is observed that with increase in irradiation dose, glass transition temperature and crystallization temperature increase. However, the thermal stability of the composites is found to increase with increase in irradiation dose.

Synthesis and Thermal Properties of a Boron-Containing Bisphenol-S Formaldehyde Resin

2011 ◽  
Vol 239-242 ◽  
pp. 2905-2908 ◽  
Author(s):  
Jun Gang Gao ◽  
Wei Hong Wu ◽  
Xing Li
Keyword(s):  
Thermal Stability ◽  
Glass Transition ◽  
Thermal Properties ◽  
Degradation Rate ◽  
Formaldehyde Resin ◽  
Curing Process ◽  
Bisphenol S ◽  
Coordinate Structure ◽  
H Nmr ◽  
Degradation Temperature

Boron-containing bisphenol-S formaldehyde resin (BBPSFR) was synthesized by formalin method. The structure and thermal properties of BBPSFR were characterized by 1H NMR, FTIR, torsional braid analysis (TBA) and thermogravimetric analysis (TGA), respectively. The results showed that the borate had formed, and the six-member ring containing boron-oxygen coordinate structure also formed during the curing process. The glass transition temperature (Tg) of BBPSFR is higher 104°C than that of bisphenol-S formaldehyde resins (BPSFR); the initial degradation temperature (Ti ) increases about 43°C; thermal degradation rate decrease and thermal stability increase significantly.

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.

Application of ionic liquid [bmim]PF6 as green plasticizer for poly(L-lactide)

e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
Puyu Zhang ◽  
Lichao Peng ◽  
Wenbin Li
Keyword(s):  
Thermal Stability ◽  
Differential Scanning Calorimetry ◽  
Ionic Liquid ◽  
Glass Transition ◽  
Transition Temperature ◽  
Poly Ethylene Glycol ◽  
Scanning Calorimetry ◽  
Poly Ethylene ◽  
Thermal Stability Of ◽  
Better Than

AbstractIonic liquid [bmim]PF6 (1-butyl-3-methylimidazolium hexafluoro phosphate) was synthesized and characterized. It was used as the plasticizer for poly(L-lactide) (PLLA). The glass transition temperature (Tg) and the thermal stability of the plasticized PLLA samples were measured by thermogravimetry (TG) and differential scanning calorimetry (DSC). Compared with poly(ethylene glycol) having Mw of 300 g/mol (PEG300), TG results showed that the thermal stability of PLLA plasticized with ionic liquid was better than that of PLLA plasticized with PEG300. The Tg of plasticized PLLA decrease with increasing the content of ionic liquid [bmim]PF6 from 2 wt.% to 10 wt.%. The Tg of PLLA can be reduced to 40°C when the content of ionic liquid [bmim]PF6 was 10 wt.%. The materials of PLLA with plasticizer were also investigated using polarizing microscope (POM), the results of which indicate that the movements of PLLA chains were improved when ionic liquid plasticizer was used.

Sign in / Sign up

Export Citation Format

Share Document