Esterification functional group approach

Trimethylbenzoic acid has two methyl groups ortho to the carboxylic acid functional group. These bulky methyl groups block the approach of the alcohol and prevent esterification from occurring under Fischer esterification conditions. A possible route to the methyl ester ... 

As has been pointed out by Cantalini et al. (2003), the cross-sensitivity of SWCNT gas sensors can lead to false alarms in a complex atmosphere. To exploit CNT-based devices, it is crucial to find ways to give them selectivity. To modify the chemical activity of SWCNTs and enhance their sensitivity to a specific gas, the common approach is to functionalise the nanotube side-wall. There are two types of functionalisation depending on the binding of the functional group onto the nanotube sidewall covalent functionafisation and non-covalent functionalisation. Covalent functionalisation of SWCNTs is often obtained from the esterification of carboxylic add groups formed on... 

The grafting to method was used for the preparation of composites with the polymers containing reactive functional groups. One of the first examples of the grafting to approach was published by Fu et al in 2001. In this work, carboxylic acid groups on the nanotube surface were converted into acyl chlorides by refluxing the samples in thionyl chloride. Then the acyl chloride functionalised CNTs have been reacted with hydroxyl groups of dendritic PEG polymers via esterification reactions. 

The functional group compatibility of the click cyclization approach also makes it amenable to a variety of other polymerization techniques. For example, cyclic polyesters have been prepared using the Lewis acid-catalyzed ring-opening polymerizations (ROPs) of lactone monomers, including e-caprolactone [47, 48] and 5-valerolactone [49] from an azide-functionaUzed alcohol. Esterification of the terminal alcohol with pentynoic anhydride provided the complementary functional groups to enable an efficient click cycHzation for molecular weights up to 15 kDa. 

Three modeling approaches can be applied to the esterification reaction kinetics the molecular species model, the functional group model, and the overall reaction model. These are schematically illustrated in Scheme 4.5. 

Esterification and polycondensation kinetics of PPSu synthesis can be well described on the basis of rather simple simulation models, taking into account the reaction kinetics and the functional group modeling approach. The latter is a very beneficial technique which includes aspects of the reaction mechanism although with the minimum computational effort. 

Introduction of a hydroxymethyl group at the ethylene bridge of EDOT represents an alternative and practical approach for the functionalization of EDOT [79], After the introduction of functional groups was performed by Williamson alkylation or esterification reaction starting from 16 (Scheme 9.15), anodic oxidation led to the corresponding polymers. 

With this in mind, the approaches that have received the major attention are either grafting of another polymeric composition and chemical modification to introduce some desirable functional group by oxidation or by some other simple chemical reaction such as esterification or etherification. 

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