New type of phenolic resin—The curing reaction of bisphenol A based benzoxazine with bisoxazoline and the properties of the cured resin. III. The cure reactivity of benzoxazine with a latent curing agent

2007 ◽  
Vol 107 (2) ◽  
pp. 710-718 ◽  
Author(s):  
Hajime Kimura ◽  
Akihiro Matsumoto ◽  
Keiko Ohtsuka
2020 ◽  
pp. 009524432092857
Author(s):  
Fozia Noreen ◽  
Ahtaram Bibi ◽  
Naila Khalid ◽  
Imran Ullah Khan

Novel azomethine ether-based compounds (A: N-((4-(9-(4-(phenylimino)methyl)phenoxy)nonyloxy)benzylidene)bezenamine and B: N-((4-(9-(4-(p-hydroxyphenylimino)methyl)phenoxy)nonyloxy)benzylidene)-4-hydroxybenzenamine) were synthesized by condensation reaction of dialdehyde, 4,4-(1,9-nonandiyle)bis(oxy)dibenzaldehyde with aromatic amines. Structures of synthesized compounds were successfully characterized by Fourier transform infrared (FTIR), ultraviolet–visible, proton nuclear magnetic resonance imaging and photoluminescence (PL) spectroscopy. The PL spectral analysis revealed that emission maxima of compounds A and B are at 475 and 500 nm, respectively, indicate blue and green light emission with large Stokes shift range (Δ λ ST, 109–138 nm). Two series of polymers: one azomethine-based polymers (C1–C5) and other without azomethine (H1–H4) were prepared by curing diglycidyl ether of bisphenol A with a synthesized curing agent (B) and commercial curing agent, respectively, in various proportions. The structural characterization of the resulting polymers was carried out by FTIR spectral analysis. Thermal properties revealed that azomethine-based polymers (C1–C5) were thermally stable up to 400°C as compared to H1–H4. The glass transition temperature of the polymers, determined by differential scanning calorimetry, was in the range 121–123°C.


2015 ◽  
Vol 44 (1) ◽  
pp. 19-25
Author(s):  
T. Maity ◽  
B.C. Samanta

Purpose – The purpose of this paper was to check effectiveness of amine functional chloroaniline acetaldehyde condensate (AFCAC) as a new curing agent for diglycidyl ether of bisphenol A (DGEBA) resin. For this purpose, first AFCAC was synthesised, characterised and then curing reaction was carried out. Design/methodology/approach – Equimolecular mixture of AFCAC and DGEBA was subjected to curing reaction, and the reaction was followed by differential scanning calorimetry (DSC) analysis. The kinetic studies of this curing reaction were also carried out from those DSC exotherms. The mechanical properties, dynamic mechanical analysis (DMA) and thermogravimetric analysis (TGA) of cured epoxy were also reported. Findings – DSC results reflected the effective first order curing reaction of AFCAC with epoxy resin. Mechanical properties reflected appreciable rigidity of AFCAC cured epoxy matrix and TGA showed that the cured epoxy networks were thermally stable up to around 297°C. Research limitations/implications – The curing agent AFCAC was synthesised by using chloroaniline and acetaldehyde in acid medium. There are some limitations for this procedure. The synthetic procedure is pH dependent. So reaction cannot be done at any pH value. The reaction must also be carried out at room temperature without any heating. To obtain low molecular weight curing agent, chloroaniline and acetaldehyde cannot be taken in equimolecular ratio because the equimolecular mixture of them produces high molecular weight condensate. This was shown in our previous publication. Some implications are also there. By changing amine and aldehyde other curing agents could be synthesised and the curing efficiency of those for epoxy resin could also be studied. Originality/value – Experimental results revealed the greater suitability of AFCAC as curing agent for DGEBA resin and novelty of AFCAC cured matrix in the field of protective coating, casting, adhesives, etc.


2018 ◽  
Vol 9 (27) ◽  
pp. 3798-3807 ◽  
Author(s):  
Pengrui Wang ◽  
Ji Hoon Park ◽  
Mahmoud Sayed ◽  
Tae-Sun Chang ◽  
Amy Moran ◽  
...  

A BPA-free polycarbonate, a new type of highly thermally stable, optically transparent and biocompatible material was prepared from a di-cyclic carbonate.


2015 ◽  
Vol 744-746 ◽  
pp. 1463-1466
Author(s):  
Xi Wang

This paper presents the synthesis of a new type of flexible epoxy curing agent and an approach to improve the toughness of epoxy resin by curing without reducing the strength and modulus of the resin-cured material. The results show that the degree of toughness reaches maximum values when the flexible curing agent is applied at weight percentages (wt.%) between 10% and 15%. When the amount of flexible curing agent added to epoxy resin weight is 10wt.%, the impact toughness and fracture toughness increases by 33.3% and 96.3%, respectively, compared with the pure epoxy resin. When the amount of flexible curing agent added to epoxy is 10wt.%, the resulting impact thoughness of the material is 19.5 kJ•m-2 at-50°C, the impact toughness of pure epoxy resin is only 7.96 kJ•m-2.


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