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Antibacterial polypropylene via surface-initiated atom transfer radical polymerization
Jinyu Huang1, Hironobu Murata, Richard R Koepsel
1Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA.
Biomacromolecules
|April 10, 2007
Summary
This study chemically modified polypropylene surfaces with poly(quaternary ammonium) (PQA) to create a non-leachable biocide. Higher molecular weight PQA coatings demonstrated superior antibacterial efficacy against Escherichia coli.
Area of Science:
- Materials Science
- Polymer Chemistry
- Biomedical Engineering
Background:
- Polypropylene (PP) is a widely used polymer but lacks inherent antimicrobial properties.
- Developing effective, non-leachable antimicrobial surfaces is crucial for preventing bacterial contamination in various applications.
- Chemical modification offers a pathway to impart biocidal functionality to polymer surfaces.
Purpose of the Study:
- To chemically graft poly(quaternary ammonium) (PQA) onto polypropylene surfaces.
- To investigate the relationship between PQA chain length and antibacterial activity.
- To confirm successful surface modification and assess biocidal efficacy against Escherichia coli (E. coli).
Main Methods:
- Surface-initiated atom transfer radical polymerization (ATRP) to grow poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) from PP.
- Conversion of tertiary amine groups in PDMAEMA to quaternary ammonium (QA) groups using ethyl bromide.
- Characterization using ATR-FTIR and contact angle measurements.
- Antibacterial activity testing against E. coli.
Main Results:
- Successful chemical grafting of PDMAEMA and conversion to PQA on PP surfaces was confirmed.
- Antibacterial activity was directly correlated with the amount of grafted PQA (number of QA units).
- PP surfaces grafted with higher molecular weight PQA (M(n) > 10,000 g/mol) achieved nearly 100% E. coli killing efficiency.
- Lower molecular weight PQA grafts (M(n) = 1,500 g/mol) showed reduced efficacy (85% killing efficiency).
Conclusions:
- Polypropylene surfaces can be effectively modified with non-leachable poly(quaternary ammonium) biocides.
- The molecular weight of the grafted PQA significantly influences the surface's antibacterial performance.
- This approach offers a promising strategy for developing antimicrobial materials with tunable efficacy.
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