Preparation and Performance of Bio-Adhesive Based on Acorn Starch Graft Glycidyl Methacrylate

2011 ◽  
Vol 121-126 ◽  
pp. 293-296
Author(s):  
Shi Feng Zhang ◽  
Lu Lu Zhou ◽  
Qiang Gao ◽  
Xu Xia Guo ◽  
Li Ou Chen ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Fourier Transform ◽  
Bonding Strength ◽  
Glycidyl Methacrylate ◽  
Water Resistance ◽  
National Standards ◽  
Curing Temperature ◽  
Type Ii ◽  
Scanning Calorimetry ◽  
And Performance

For improving the performance of acorn starch (AS) based bio-adhesive, AS graft glycidyl methacrylate (AS-g-GMA) adhesive was prepared in this paper. The properties of the AS-g-GMA adhesive were studied by Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) measurement. The bonding strength of the plywood bonded by AS-g-GMA adhesive was measured according to Chinese National Standards methods to evaluate its water resistant. FTIR results indicated that GMA was grafted on the AS successfully. The bonding strength of the plywood bonded by AS-g-GMA adhesive showed lower curing temperature, better bonding strength, and water resistance comparing with that of control. The water resistant could reach type II grade (63°C water bath 3h) plywood requirement when the glycidyl methacrylate adding amount was 6% based on AS.

Fast Curing Phenol-Formaldehyde Resin Catalyzed by a Complex Catalyst

2010 ◽  
Vol 113-116 ◽  
pp. 2124-2128 ◽  
Author(s):  
Shi Feng Zhang ◽  
Jian Zhang Li ◽  
Xiao Ying Liu ◽  
Yan An Ou ◽  
Qiang Gao
Keyword(s):  
Bonding Strength ◽  
Phenol Formaldehyde ◽  
Formaldehyde Emission ◽  
National Standards ◽  
Curing Temperature ◽  
Formaldehyde Resin ◽  
Hot Press ◽  
Scanning Calorimetry ◽  
Complex Catalyst ◽  
Press Temperature

For increasing the curing rate and decreasing the curing temperature, modified phenol-formaldehyde (PF) resins were synthesized under a complex catalyst. The bonding strength and formaldehyde emission of the plywood bonded by them were measured according to Chinese National Standards methods. The curing behavior was conducted by differential scanning calorimetry (DSC) measurement. The results indicate that PF resins catalyzed by the complex catalyst show more moderate pH values, lower curing temperature and shorter gel time comparing with control ones. Plywood bonded with modified PF resins shows good bonding strength and low formaldehyde emission even at low hot press temperature (110 °C), which is closed to the plywood bonded with normal control PF resin at high hot press temperature (130 °C).

Copper salt–assisted polymerization of bispropargyl ether–bismaleimide blend

2018 ◽  
Vol 51 (1) ◽  
pp. 52-63
Author(s):  
J Dhanalakshmi ◽  
CT Vijayakumar
Keyword(s):  
Thermal Stability ◽  
Differential Scanning Calorimetry ◽  
Fourier Transform ◽  
Copper Salt ◽  
Curing Temperature ◽  
Scanning Calorimetry ◽  
Infrared Spectrophotometer ◽  
Lower Temperature ◽  
Lower Temperature Region

Bispropargyl ether (BPE) of bisphenol-A was prepared. It was blended with 4,4’-bismaleimido diphenyl methane (BMI, 0.5:0.5 mol). The copper sulphate pentahydrate (CuSO4·5H2O) was blended (1% w/w) separately with pure BPE and BPE-BMI blend and the materials were thermally cured. The structural characterization of the materials was done using a Fourier-transform infrared spectrophotometer. The curing behaviour of the materials was investigated using differential scanning calorimetry. The presence of copper salt in BPE shifted the curing temperature to lower temperature region. The presence of copper salt in BPE-BMI blend also decreased the curing onset temperature by approximately 15°C. The thermal property of the polymers was investigated using thermogravimetry. The incorporation of copper salt in BPE-BMI blend led to polymer with increased thermal stability.

scholarly journals SYNTHESIS OF BENZOXAZINE MONOMER WITH LOW CURING TEMPERATURE FROM RENEWABLE DIPHENOLIC ACID, BENZYLAMINE AND PARAFORMALDEHYDE

2018 ◽  
Vol 55 (1B) ◽  
pp. 63
Author(s):  
Cao Xuan Viet
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Differential Scanning Calorimetry ◽  
Fourier Transform ◽  
Exothermic Peak ◽  
Curing Temperature ◽  
Carboxyl Groups ◽  
Polymerization Temperature ◽  
Scanning Calorimetry ◽  
Monomer Structure ◽  
13C Nuclear Magnetic Resonance

The aim of this study was to examine the use of renewable diphenolic acid (DPA) as starting materials together with benzylamine and paraformaldehyde for the synthesis of novel polybenzoxazine resin with low curing temperature. The monomer structure was confirmed by 1H and 13C nuclear magnetic resonance (NMR) spectroscopy, and Fourier transform infrared (FTIR) spectroscopy. Differential scanning calorimetry (DSC) was also used to study crosslinking behavior of synthesized material. The benzoxazine monomer exhibited low exothermic peak with the onset around 162 °C, which is significantly lower than conventional benzoxazines derived from bisphenol A. The presence of carboxyl groups in monomer structure is responsible for the low polymerization temperature of this monomer.

scholarly journals Comparative thermal research on tetraazapentalene-derived heat-resistant energetic structures

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Jing Zhou ◽  
Li Ding ◽  
Yong Zhu ◽  
Bozhou Wang ◽  
Xiangzhi Li ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Thermal Decomposition ◽  
Fourier Transform ◽  
Energetic Materials ◽  
Great Influence ◽  
Fourier Transform Infrared ◽  
Thermal Decomposition Mechanism ◽  
Scanning Calorimetry ◽  
In Situ Ftir Spectroscopy ◽  
Heat Resistant

AbstractOrganic inner salt structures are ideal backbones for heat-resistant energetic materials and systematic studies towards the thermal properties of energetic organic inner salt structures are crucial to their applications. Herein, we report a comparative thermal research of two energetic organic inner salts with different tetraazapentalene backbones. Detailed thermal decomposition behaviors and kinetics were investigated through differential scanning calorimetry and thermogravimetric analysis (DSC-TG) methods, showing that the thermal stability of the inner salts is higher than most of the traditional heat-resistant energetic materials. Further studies towards the thermal decomposition mechanism were carried out through condensed-phase thermolysis/Fourier-transform infrared (in-situ FTIR) spectroscopy and the combination of differential scanning calorimetry-thermogravimetry-mass spectrometry-Fourier-transform infrared spectroscopy (DSC-TG-MS-FTIR) techniques. The experiment and calculation results prove that the arrangement of the inner salt backbones has great influence on the thermal decompositions of the corresponding energetic materials. The weak N4-N5 bond in “y-” pattern tetraazapentalene backbone lead to early decomposition process and the “z-” pattern tetraazapentalene backbone exhibits more concentrated decomposition behaviors.

scholarly journals Conversion of palm oil to new sulfur-based polymer by inverse vulcanization

2021 ◽  
Vol 287 ◽  
pp. 02014
Author(s):  
Amin Abbasi ◽  
Mohamed Mahmoud Nasef ◽  
Wan Zaireen Nisa Yahya ◽  
Muhammad Moniruzzaman
Keyword(s):  
Thermal Stability ◽  
Differential Scanning Calorimetry ◽  
Fourier Transform ◽  
Thermogravimetric Analysis ◽  
Palm Oil ◽  
Elemental Sulfur ◽  
Molten State ◽  
Scanning Calorimetry ◽  
Environmental Friendly ◽  
Sulfur Containing

The conversion of palm oil into a sulfur-based polymer by copolymerization with sulfur powder at its molten state is herein reported. The obtained sulfur-containing polymer was characterized using Fourier transform infrared (FTIR), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC) to demonstrate the successful conversion. The disappearance of the peaks related to vinylic groups of oil together with the appearance of a peak representing C-H rocking vibrations in the vicinity of C-S bonds confirmed the copolymerization of sulfur with oil. TGA revealed that the polymers have thermal stability up to 230°C under nitrogen and the polymers leave 10% sulfur-rich ash. DSC proved that a small amount of elemental sulfur remained unreacted in the polymer, which showed amorphous and heavily crosslinked structure resembling thermosets. These copolymers are an environmental-friendly polymeric material promoting the utilization of the abundant sulfur while also adding value to palm oil.

scholarly journals Swelling properties of chitosan hydrogels

2004 ◽  
Vol 22 (1) ◽  
pp. 32 ◽  
Author(s):  
David R Rohindra ◽  
Ashveen V Nand ◽  
Jagjit R Khurma
Keyword(s):  
Differential Scanning Calorimetry ◽  
Fourier Transform ◽  
Glass Transition ◽  
Free Water ◽  
Scanning Calorimetry ◽  
Swelling Behaviour ◽  
Swelling Properties ◽  
Different Temperatures ◽  
Ft Ir ◽  
Chitosan Hydrogels

Chitosan hydrogels were prepared by crosslinking chitosan with glutaraldehyde. The swelling behaviour of the crosslinked and uncross-linked hydrogels was measured by swelling the gels in media of different pH and at different temperatures. The swelling behavior was observed to be dependent on pH, temperature and the degree of crosslinking. The gel films were characterized by Fourier transform Infrared spectroscopy (FT-IR) and Differential Scanning Calorimetry (DSC). The glass transition temperature (Tg) and the amount of free water in the hydrogels decreased with increasing crosslinking in the hydrogels.

scholarly journals Influence of Single/Collective Use of Curing Agents on the Curing Behavior and Bond Strength of Soy Protein-Melamine-Urea-Formaldehyde (SMUF) Resin for Plywood Assembly

Polymers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 1995 ◽  
Author(s):  
Zhigang Wu ◽  
Bengang Zhang ◽  
Xiaojian Zhou ◽  
Lifen Li ◽  
Liping Yu ◽  
...  
Keyword(s):  
Shear Strength ◽  
Water Resistance ◽  
Protein Hydrolysate ◽  
Soybean Protein ◽  
Urea Formaldehyde ◽  
Curing Temperature ◽  
Molar Ratio ◽  
Scanning Calorimetry ◽  
Curing Agents ◽  
Crosslinking Reactions

Soybean protein hydrolysate, melamine, urea, and concentrated formaldehyde were used to synthesize an environmentally friendly soybean protein-melamine-urea-formaldehyde (SMUF) co-condensation resin. (NH4)2SO4, (NH4)2HPO4, (NH4)2HPO4 + (NH4)2SO4, (NH4)2HPO4 + (NH4)2S2O8, and (NH4)2HPO4 + (NH4)2SO4 + (NH4)2S2O8 were employed as curing agents for SMUF resin. The curing and thermal behaviors of the SMUF resin were investigated using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). The results revealed the following: (1) (NH4)2SO4 alone could not cure the SMUF resin completely; thus, the final shear strength accomplished plywood with the resin was low, and its water resistance was poor, while the adhesive section was loose and porous/brittle after curing. (2) (NH4)2HPO4 could be hydrolyzed to generate H+ and promote SMUF curing, but it could also form polyphosphoric acids, resulting in crosslinking reactions with SMUF in parallel; thereby, the curing properties were improved. (3) When (NH4)2HPO4 + (NH4)2SO4 + (NH4)2S2O8 were engaged collectively as curing agent, the shear strength, water resistance, and heat resistance of SMUF attained were the best possible whereas the curing temperature was decreased and the heat released by curing was elevated substantially, which signifies maximized extent of crosslinking was achieved. Further, the adhesive section exhibited mostly a crosslinking intertexture as demonstrated by means of SEM. Accordingly, this study may serve as a guide for the curing of amino resins, with low-molar ratio of formaldehyde to amine in adhesives, which are applied to plywood production.

Curing behaviors of cyanate ester/epoxy copolymers and their dielectric properties

2016 ◽  
Vol 29 (10) ◽  
pp. 1175-1184 ◽  
Author(s):  
Yangxue Lei ◽  
Mingzhen Xu ◽  
Mingli Jiang ◽  
Yumin Huang ◽  
Xiaobo Liu
Keyword(s):  
Differential Scanning Calorimetry ◽  
Thermal Decomposition ◽  
Fourier Transform ◽  
Dielectric Properties ◽  
Small Extent ◽  
Dielectric Constants ◽  
Cyanate Ester ◽  
Scanning Calorimetry ◽  
Peak Fitting ◽  
Curing Kinetic

The curing behavior and dielectric properties of cyanate ester/epoxy (EP) with a latent initiator imidazole was investigated as a function of blend composition. Differential scanning calorimetry (DSC) was used to investigate the dynamic cure behavior of the blends. Multiheating rate DSC, peak fitting, and iso-conversion method were applied to analyze the curing kinetic parameters. Two distinct peaks were fitted from the dynamic DSC curve and the activation energies of each reaction varied with the increase of curing degrees. Fourier transform infrared spectra revealed that several reactions coexisted during the curing processes of cyanate and EP, resulting in the coexistence of the polymers and copolymers in the final composites. The dielectric properties of the composites were studied and the phenomenon that the dielectric constants for all of the composites are independent of frequency was observed. The thermal decomposition characteristics of the blends were investigated using thermogravimetric analysis. By increasing the content of EP, the thermal properties of the cured blends were improved to a small extent, while the char yield markedly decreased.

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