scholarly journals Structural Characterization of Cure Bio-based Phenol Formaldehyde Wood Adhesive

2020 ◽  
pp. 12-19
Author(s):  
Y. B. Olayiwola
Keyword(s):  
13C Nmr ◽  
Liquid State ◽  
Phenol Formaldehyde ◽  
Wood Adhesive ◽  
Resin System ◽  
Nmr Study ◽  
13C Nmr Analysis ◽  
13C Nuclear Magnetic Resonance ◽  
Phenolic Components

Bio-phenol formaldehyde (BPF) resole resins were characterized by liquid-state 13C Nuclear Magnetic Resonance (NMR) spectroscopy. The liquid 13C NMR analysis indicated that the condensation reactions between the bark phenolic compounds and the formaldehyde occurred during the synthesis of the resins. Methylene ether bridges in the resins were more pronounced in the BPF resin when compared to the PF resin system. The liquid-state 13C NMR study revealed significant differences in the resins structures induced by the inclusion of bark-phenolic components. The bark-phenolic components favored the formation of para-ortho methylene linkages in the BPF resins and also enhanced the cure rate of the BPF resin system.

scholarly journals Study on Soy-Based Adhesives Enhanced by Phenol Formaldehyde Cross-Linker

Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 365 ◽  
Author(s):  
Zhigang Wu ◽  
Xuedong Xi ◽  
Hong Lei ◽  
Jiankun Liang ◽  
Jingjing Liao ◽  
...  
Keyword(s):  
13C Nmr ◽  
Soy Protein ◽  
Water Resistance ◽  
Phenol Formaldehyde ◽  
Ionization Mass ◽  
Model Compounds ◽  
Esi Ms ◽  
13C Nuclear Magnetic Resonance ◽  
Ft Ir ◽  
Cross Linker

To find the effects of cross-linker phenol-formaldehyde (PF) resin on the performance of soy-based adhesives, the reaction between model compounds hydroxymethyl phenol (HPF) and glutamic acid were studied in this paper. HPF prepared in laboratory conditions showed higher content of hydroxymethyl groups than normal PF resin, which was proved by the results of Electrospray Ionization Mass Spectrometry (ESI-MS) and 13C Nuclear Magnetic Resonance (13C-NMR). The results of ESI-MS, Fourier transform infrared spectroscopy (FT-IR), and 13C-NMR based on resultant products obtained from model compounds showed better water resistance of the soy protein-based adhesive modified by PF-based resin, which indicated the reaction between PF resin and soy protein. However, it seemed that the soy-based adhesive cross-linked by HPF with the maximum content of hydroxymethyl groups did not show the best water resistance.

Synthesis and 13C-NMR analysis of an ethylene copolymer with 9-decen-1-ol

RSC Advances ◽  
2015 ◽  
Vol 5 (120) ◽  
pp. 98929-98933 ◽  
Author(s):  
Liping Hou ◽  
Wei Wang ◽  
Jianfang Sheng ◽  
Changcheng Liu
Keyword(s):  
13C Nmr ◽  
Synthesis And Characterization ◽  
Nmr Analysis ◽  
Polymer Microstructure ◽  
13C Nmr Analysis ◽  
Ethylene Copolymer ◽  
Polymerization Conditions

Synthesis and characterization of an ethylene/9-dencen-1-ol copolymer revealed the effect of polymerization conditions, catalysts and comonomer on the activity and polymer microstructure.

Characterization of one-step, chromate-free, primer systems using liquid-state 29Si and 13C NMR

2007 ◽  
Vol 60 (3) ◽  
pp. 170-177 ◽  
Author(s):  
A. Seth ◽  
W.J. van Ooij ◽  
P. Puomi ◽  
T. Metroke ◽  
A. Apblett
Keyword(s):  
13C Nmr ◽  
Liquid State ◽  
One Step

scholarly journals Synthesis and Characterization of Cationic Tetramethyl Tantalum(V) Complex

Catalysts ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 507 ◽  
Author(s):  
Raju Dey ◽  
Janet Mohandas ◽  
Manoja Samantaray ◽  
Ali Hamieh ◽  
Santosh Kavitake ◽  
...  
Keyword(s):  
1H Nmr ◽  
13C Nmr ◽  
Liquid State ◽  
Correlation Spectroscopy ◽  
Synthesis And Characterization ◽  
Novel Method

A novel method for the synthesis of the homogeneous homoleptic cationic tantalum(V)tetramethyl complex [(TaMe4)+ MeB(C6F5)3−] from neutral tantalumpentamethyl (TaMe5) has been described, by direct demethylation using B(C6F5)3 reagent. The aforesaid higher valent cationic tantalum complex was characterized precisely by liquid state 1H-NMR, 13C-NMR, and 1H-13C-NMR correlation spectroscopy.

13C NMR Analysis of Carbon-13 Enriched Ethylene Copolymers with Propylene

1979 ◽  
Vol 52 (1) ◽  
pp. 1-8 ◽  
Author(s):  
E. G. Brame ◽  
H. E. Holmquist
Keyword(s):  
13C Nmr ◽  
Population Distribution ◽  
Length Distribution ◽  
Large Error ◽  
Sequence Length ◽  
Distribution Method ◽  
Ethylene Propylene ◽  
13C Nmr Analysis ◽  
Equal Population

Abstract Carbon-13 nuclear magnetic resonance (13C NMR) has been used rather extensively in the characterization of ethylene-propylene copolymers and terpolymers. Chemical shift assignments on these copolymers were first made by Carman and revised only slightly by him recently. Despite all the work that has been done to assign the lines in the 13C NMR spectrum to the various sequence structures in ethylene-propylene copolymers, ambiguity still remains in some of the assignments, such as the assignment of the Sαβ line. It still is not known whether it is attributable entirely to two propylenes with one of them inverted, to an ethylene sandwiched between two propylenes with one of them inverted, or to an equal population distribution of these two structures. Carman and coworkers state that inversion of propylene in their copolymers is certain, but because of the large error in the calculation, the degree of inversion can be between 10 and 40% of the propylene content. His suggestion is that the Sαβ line is attributable to a combination of the two structure forms indicated above. Tanaka6 also makes this same suggestion in his 13C NMR work. He based his conclusion on some earlier infrared work. Most recently Randall describes a sequence length distribution method in which he estimates that the total amount of propylene inversions is the order of 20–30% for a concentration range of about 50–60 wt% propylene in copolymers with ethylene. Ray does not have to deal with the problem, as his 13C NMR spectra show no evidence of propylene inversions. His copolymers were prepared with an aluminum-titanium catalyst. Ours as well as Carman's were prepared with an aluminum-vanadium catalyst. Our reason for undertaking this program was to aid in the assignment of the Sαβ line. For this effort we prepared a series of ethylene-propylene copolymers that are carbon-13 enriched in both carbons of the ethylene, and we analyzed them by 13C NMR.

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