Determination of Polymer Type and Content in Concrete Materials by FTIR and TGA

Significance of the Topic

Adding polymers like EVA or SBR to cement enhances workability adhesion curing strength and durability requiring accurate determination of polymer content for quality control and optimal performance

• Improved mechanical and curing properties
• Customized formulations for niche applications
• Need for rapid and reliable quantification methods

Objectives and Study Overview

This study evaluates FTIR spectroscopy with chemometric analysis and TGA to identify polymer type and quantify polymer cement and aggregate content in modified concrete mixtures prepared at controlled polymer-cement ratios

Methodology and Instrumentation

Sample Preparation

• EVA cement aggregate mixtures with varying polymer loadings
• Polymer extraction from mixtures using THF

FTIR Analysis

• ATR accessory on IRTracer-100 for raw and extracted polymer identification
• DRS accessory on IRTracer-100 with PLS calibration for quantitative analysis

TGA Analysis

• DTG-60 simultaneous DTA-TGA from room temperature to 600 C under nitrogen
• Polymer content determined from weight loss between 200 and 600 C

Main Results and Discussion

FTIR-ATR confirmed presence of EVA and fillers in raw material and pure EVA in extracted samples by matching characteristic absorption peaks

• Extracted polymer spectrum aligned with EVA reference

FTIR-DRS and PLS

• Multicomponent calibration for polymer cement and aggregate using 42 reference spectra
• Second derivative preprocessing improved peak resolution
• High correlation coefficients (R2 > 0.995) and low prediction errors
• Validation samples showed recovery within 95 to 105 percent

TGA Quantification

• Weight loss profiles consistent across samples
• Polymer content reproducibility below 3 percent RSD
• Linear calibration between TGA polymer loss and raw EVA content (R2 = 0.9993)

Benefits and Practical Applications

• Rapid simultaneous quantification of polymer cement and aggregate
• Minimal sample preparation for FTIR-DRS PLS analysis
• Reliable polymer content determination by TGA
• Supports quality control and material screening in construction

Future Trends and Opportunities

Expanding the methodology to other polymer modifiers and concrete formulations

• Integration of advanced chemometric algorithms for enhanced accuracy
• Coupling TGA with FTIR for real-time gas analysis
• Automation of sample handling for high throughput testing

Conclusion

FTIR combined with chemometrics and TGA provide complementary and reliable approaches for identifying and quantifying polymer content in modified concrete materials enabling efficient quality control and formulation optimization

References

1. Ohama Y Handbook of Polymer-Modified Concrete and Mortars Noyes Publications 1995
2. ASTM E1131 Standard Test Method for Compositional Analysis by TGA 1997
3. Tokura T Lim J Chua AM Ohta M Naganishi A Takeuchi S Analysis of Gaseous Products by DTA/TGA-FTIR System Shimadzu Review 71 2015 129 133