Related Experiment Video
Updated: Jul 10, 2026
10:22
Designed for Molecular Recycling: A Lignin-Derived Semi-aromatic Biobased Polymer
Published on: November 30, 2020
Enhancing the functionality of biobased polyester coating resins through modification with citric acid
Bart A J Noordover1, Robbert Duchateau, Rolf A T M van Benthem
1Laboratory of Polymer Chemistry, Eindhoven University of Technology, Den Dolech 2, 5600 MB Eindhoven, The Netherlands.
Biomacromolecules
|November 13, 2007
Summary
Citric acid (CA) enhances biobased polyesters for coatings by forming anhydride intermediates. This modification improves functionality, leading to stable, rapidly curing biobased coating systems.
Area of Science:
- Polymer Chemistry
- Materials Science
- Sustainable Chemistry
Background:
- Biobased polyesters are desirable for sustainable coating applications.
- Functionalizing hydroxyl-terminated polyesters is key to enhancing their performance.
- Citric acid (CA) offers potential as a biobased monomer for polyester modification.
Purpose of the Study:
- To evaluate citric acid as a functionality-enhancing monomer in biobased polyesters.
- To investigate the use of CA's anhydride formation for modifying polyesters.
- To develop fully biobased coating systems with improved properties.
Main Methods:
- Model esterification reactions of CA with various alcohols and diols catalyzed by titanium(IV) n-butoxide.
- Melt reaction of OH-functional polyesters with CA at 150-165°C.
- Simulation of acid/epoxy curing reactions and application of modified polyesters as coatings.
Main Results:
- Titanium(IV) n-butoxide catalyzed esterification at low temperatures, often via anhydride intermediates.
- Facile anhydride formation of CA at ~153°C crucial for modifying hindered hydroxyl groups.
- CA-modified polyesters exhibited enhanced functionality, rapid curing, and formed stable coatings.
Conclusions:
- Citric acid can be effectively used via its anhydride formation to functionalize OH-polyesters.
- This novel approach is a significant step towards fully biobased coating systems.
- The developed CA-modified polyesters offer a sustainable alternative for coating applications.
Related Concept Videos
01:20Types of Step-Growth Polymers: Polyesters
The introduction of polyesters has brought major development to the textile industry. The wrinkle-free behavior of polyester blends has eliminated the need for starching and ironing clothes.
Polyesters are commonly prepared from terephthalic acid and ethylene glycol; the crude product is known as poly(ethylene terephthalate) or PET. However, polyesters are synthesized industrially by transesterification of dimethyl terephthalate with ethylene glycol at 150 °C. The two reactants and the polymer...
Polyesters are commonly prepared from terephthalic acid and ethylene glycol; the crude product is known as poly(ethylene terephthalate) or PET. However, polyesters are synthesized industrially by transesterification of dimethyl terephthalate with ethylene glycol at 150 °C. The two reactants and the polymer...
01:27Bioplastics
Bioplastics derived from microbial processes present a sustainable alternative to conventional petroleum-based plastics. Among these, polyhydroxyalkanoates (PHAs), particularly polyhydroxybutyrates (PHBs), have emerged as prominent candidates due to their biodegradability and biocompatibility. These polymers are synthesized by a variety of bacteria, such as Cupriavidus necator and Pseudomonas putida, which naturally accumulate PHAs as intracellular carbon and energy reserves, especially under...
01:25Production of Organic Acids
Lactic acid, an important organic acid extensively applied in food, pharmaceutical, and biodegradable polymer industries, is primarily produced via microbial fermentation. This method is favored over chemical synthesis due to its environmental sustainability and capacity for enantiomerically pure product formation. Among various microbial processes, the fermentation of starch-based substrates stands out due to the abundance and renewability of raw materials like corn and potatoes.Hydrolysis of...
01:37The Citric Acid Cycle: Overview
In aerobic organisms, the citric acid cycle is the second stage of cellular respiration wherein molecules derived from the breakdown of carbohydrates, proteins, and fats are oxidized into carbon dioxide and energy. This process is also known as the tricarboxylic acid (TCA) cycle as the first product of the cycle, citric acid, contains three carboxyl groups in its structure. Alternatively, this cycle is also referred to as the Krebs cycle, in honor of its discoverer Sir Hans Krebs.
The citric...
The citric...
01:13Esters to Carboxylic Acids: Acid-Catalyzed Hydrolysis
Hydrolysis of esters under acidic conditions proceeds through a nucleophilic acyl substitution. In the presence of excess water, the reaction proceeds in a reversible manner, forming carboxylic acids and alcohols.
During hydrolysis, the ester is first activated towards nucleophilic attack through the protonation of the carboxyl oxygen atom by the acid catalyst. The protonation makes the ester carbonyl carbon more electrophilic. In the next step, water acts as a nucleophile and adds to the...
During hydrolysis, the ester is first activated towards nucleophilic attack through the protonation of the carboxyl oxygen atom by the acid catalyst. The protonation makes the ester carbonyl carbon more electrophilic. In the next step, water acts as a nucleophile and adds to the...
01:20Carboxylic Acids to Esters: Acid-Catalyzed (Fischer) Esterification Overview
The Fischer esterification reaction was developed by the German chemist Emil Fischer in 1895. It is a condensation reaction between carboxylic acids and alcohols in an acidic medium to give esters and water.