Anionic Cross-Linking of Polymers Having an Epoxy Group in the Side Chain with Bicyclic and Spirocyclic Bis(γ-lactone)s

1997 ◽  
Vol 30 (9) ◽  
pp. 2532-2538 ◽  
Author(s):  
Keunwo Chung ◽  
Toshikazu Takata ◽  
Takeshi Endo
Keyword(s):  
Epoxy Group ◽  
Side Chain ◽  
Cross Linking

Side-Chain Cholesteric Liquid Crystalline Elastomers Derived from a Mesogenic Cross-Linking Agent

2003 ◽  
Vol 36 (24) ◽  
pp. 9060-9066 ◽  
Author(s):  
Jian-She Hu ◽  
Bao-Yan Zhang ◽  
Ying-Gang Jia ◽  
Song Chen
Keyword(s):  
Liquid Crystalline ◽  
Side Chain ◽  
Cross Linking ◽  
Cholesteric Liquid Crystalline

Study on Synthesis and Characterization of Unsaturated Polyester by Enzyme-Catalyzed

2013 ◽  
Vol 575-576 ◽  
pp. 67-70
Author(s):  
Fen Juan Shao ◽  
Qun Yang ◽  
Lan Ying Li ◽  
Da Nian Lu
Keyword(s):  
High Temperature ◽  
Unsaturated Polyester ◽  
Soxhlet Extraction ◽  
Side Chain ◽  
Synthesis And Characterization ◽  
Cross Linking ◽  
Cross Link ◽  
H Nmr ◽  
Ft Ir

Unsaturated polyester was prepared with adipic acid (AA), fumaric acid (FA), itaconic acid (IA) and 1, 6-hexanediol (HD) by enzyme-catalyzed polmerization. The insoluble gel fraction (Qs), as the cross-linking degree of cured unsaturated polyesters which could be self-cross-linked at high temperature through C=C in it, was got by Soxhlet Extraction. The properties were investigated by FT-IR, 1H NMR, DSC, XRD and so on. The results indicated that the C=C in unsaturated diacids reduced the acitvity of N435, which affected the polmerization. With the introduction of C=C of IA or FA, the Mn of polyester reduced. The C=C could self-cross-link under high temperature for lengthy time. The higher the temperature and the longer the time, the Qs increased. As the C=C of IA was in the side chain, it could move easily. Then Qs of poly (AA-co-IA-co-HD) was higher than ploy (AA-co-FA-co-HD). With the increased content of unsaturated diacid, Qs increased. And the biodegradation of cross-linked polyesters became worse.

Epoxy Modified with TDI to Cure Active Hydrogen Groups: Synthesis and Characterization

2012 ◽  
Vol 531 ◽  
pp. 511-515
Author(s):  
Zhi Gang Liu ◽  
Jing Jing Xu ◽  
Yan Lan Qin ◽  
Ju Sheng Zhang ◽  
Qian Lan Rao
Keyword(s):  
Corrosion Resistance ◽  
Ir Spectra ◽  
Epoxy Resin ◽  
Epoxy Group ◽  
Coal Tar ◽  
Toluene Diisocyanate ◽  
Synthesis And Characterization ◽  
Cross Linking ◽  
Curing Agent ◽  
Active Hydrogen

Study on isocyanate-terminated prepolymer prepared by the reaction of toluene diisocyanate (TDI) with the hydroxy of epoxy resin. By the characteristics that isocyanate-group reacts with active hydrogen groups easily, the prepolymer could be as a curing agent for substance with active hydrogen groups like coal tar. IR spectra showed that the modification was achieved by cross-linking the hydroxy of epoxy resin and the isocyanate of TDI, but epoxy group had no change. In self-made coal tar coatings, the remaining isocyanate-groups played a curing agent role linking coal tar and epoxy resin. Tafel test showed the films with prepolymer was more corrosion resistance, combined the characteristics of the epoxy resin and coal tar.

Cross-Linking Behavior of Diskotic Side-Chain Polymers in Solution

2004 ◽  
Vol 37 (20) ◽  
pp. 7839-7845 ◽  
Author(s):  
Marcel W. C. P. Franse ◽  
Klaas te Nijenhuis ◽  
Jan Groenewold ◽  
Stephen J. Picken
Keyword(s):  
Side Chain ◽  
Cross Linking

Preparation of polyferrocenylsilane via thermal ROP, synthesis of polyferrocenylsilane with methacrylate side chain and its photochemical cross-linking properties

2006 ◽  
Vol 60 (11) ◽  
pp. 1416-1419 ◽  
Author(s):  
Jian-Jun Wang ◽  
Li Wang ◽  
Xue-Jie Wang ◽  
Tao Chen ◽  
Hao-Jie Yu ◽  
...  
Keyword(s):  
Side Chain ◽  
Cross Linking

Engineering oxidative stability in human hemoglobin based on the Hb providence (βK82D) mutation and genetic cross-linking

2017 ◽  
Vol 474 (24) ◽  
pp. 4171-4192 ◽  
Author(s):  
Michael Brad Strader ◽  
Rachel Bangle ◽  
Claire J. Parker Siburt ◽  
Cornelius L. Varnado ◽  
Jayashree Soman ◽  
...  
Keyword(s):  
Oxidative Degradation ◽  
Oxygen Affinity ◽  
Side Chain ◽  
Cross Linking ◽  
Critical Element ◽  
Low Oxygen ◽  
Naturally Occurring ◽  
Low Concentrations ◽  
Genetic Cross ◽  
Low Oxygen Affinity

Previous work suggested that hemoglobin (Hb) tetramer formation slows autoxidation and hemin loss and that the naturally occurring mutant, Hb Providence (HbProv; βK82D), is much more resistant to degradation by H2O2. We have examined systematically the effects of genetic cross-linking of Hb tetramers with and without the HbProv mutation on autoxidation, hemin loss, and reactions with H2O2, using native HbA and various wild-type recombinant Hbs as controls. Genetically cross-linked Hb Presbyterian (βN108K) was also examined as an example of a low oxygen affinity tetramer. Our conclusions are: (a) at low concentrations, all the cross-linked tetramers show smaller rates of autoxidation and hemin loss than HbA, which can dissociate into much less stable dimers and (b) the HbProv βK82D mutation confers more resistance to degradation by H2O2, by markedly inhibiting oxidation of the β93 cysteine side chain, particularly in cross-linked tetramers and even in the presence of the destabilizing Hb Presbyterian mutation. These results show that cross-linking and the βK82D mutation do enhance the resistance of Hb to oxidative degradation, a critical element in the design of a safe and effective oxygen therapeutic.

scholarly journals Tyrosine Metabolism in Blowfly Larvae at Pupation

1964 ◽  
Vol 17 (3) ◽  
pp. 803 ◽  
Author(s):  
RH Hackman KN Saxen
Keyword(s):  
Direct Evidence ◽  
Side Chain ◽  
Cross Linking ◽  
Cuticular Protein ◽  
Oxidative Deamination ◽  
Tyrosine Metabolism ◽  
Metabolic Reactions

In insects tyrosine has been regarded as participating in metabolic reactions which lead, not only to its incorporation in various proteins, but also to sclerotization of the cuticle (i.e. quinone cross-linking of cuticular protein). Three different meta-bolic pathways have been suggested, all of which lack direct evidence to support them. The suggested pathways are (i) oxidative deamination leading to the formation of o-quinones, (ii) non-specific hydroxylation and elimination of the side-chain leading to the formation of p-quinones, and (iii) conversion to N-acetyldopamine which is the phenolic precursor of the sclerotizing quinone. For a review of these theories see Pryor (1962) and Hackman (1964).

scholarly journals Oropheayunnol, an Unusual 22,23-Epoxy Apotirucallane Triterpenoid from Orophea Yunnanensis

2012 ◽  
Vol 7 (4) ◽  
pp. 1934578X1200700
Author(s):  
Wen-Jian Lan ◽  
Jun Wang ◽  
Yan-Qiong Guo ◽  
Sheng Yin
Keyword(s):  
Nasopharyngeal Carcinoma ◽  
Cell Line ◽  
Carcinoma Cell ◽  
Epoxy Group ◽  
2D Nmr ◽  
Side Chain ◽  
Spectroscopic Methods ◽  
Phytochemical Study ◽  
Nasopharyngeal Carcinoma Cell

A new apotirucallane-type triterpenoid with an unusual 22,23-epoxy group in the side chain, 22,23-epoxy-apotirucalla-14-ene-3α,7α,24α,25-tetraol (1), was isolated from the leaves and twigs of Orophea yunnanensis. The structure of 1 was established on the basis of HRESIMS, 1D, and 2D NMR spectroscopic methods. This is the first phytochemical study of Orophea yunnanensis, and the biogenetic origin of 1 was postulated. Compound 1 exhibited weak cytotoxicity in vitro against the growth of CNE1 nasopharyngeal carcinoma cell line with an IC50 value of 9.7 μg/mL.

Helix-Constrained Peptides Constructed by Head-to-Side Chain Cross-Linking Strategies

2021 ◽  
Author(s):  
Xiao-Xu Chen ◽  
Yang Tang ◽  
Meng Wu ◽  
Yan-Ni Zhang ◽  
Kai Chen ◽  
...  
Keyword(s):  
Side Chain ◽  
Cross Linking ◽  
Constrained Peptides
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