Development of Novel Thermochromic Polymer Composites for Intelligent Packaging Applications in Nigeria’s Cold Chain Logistics Sector: Synthesis, Mechanism, and Commercial Viability

Cold chain integrity failures during food and pharmaceutical distribution in Nigeria cause significant economic losses and public health risks, creating demand for intelligent packaging systems that provide visible temperature abuse indicators to protect consumers and operators. This research develops novel thermochromic polymer composite systems for intelligent packaging applications, investigating synthesis routes, colour change mechanisms, performance under Nigerian distribution conditions, and commercial viability for implementation in the cold chain logistics sector. Thermochromic composites were synthesised by encapsulating thermochromic dye-developer-solvent ternary systems in polymethylmethacrylate and urea-formaldehyde microcapsule shells, and by fabricating composites of leuco dye systems with polylactic acid and polyethylene matrices. Colour change temperature, reversibility, colour intensity, response time, and repeatability were characterised by UV-visible spectrophotometry integrated with precision temperature control. Durability under UV exposure, humidity cycling, and mechanical stress representative of Nigerian distribution handling was assessed. The thermochromic transition mechanism was elucidated by differential scanning calorimetry, FTIR spectroscopy, and molecular dynamics simulation of dye-developer-solvent interactions. A techno-economic model evaluated the commercial viability of thermochromic packaging integration for the Nigerian pharmaceutical cold chain, accounting for packaging cost increment, product protection value, and supply chain monitoring efficiency gains. Results demonstrate that optimised encapsulated systems achieved colour change temperatures of 4, 8, and 12 degrees Celsius with temperature precision of plus or minus 0.6 degrees Celsius, suitable for pharmaceutical product temperature requirement differentiation. Response time was less than 30 seconds for transition initiation, with full colour saturation within 120 seconds. UV durability testing confirmed stable performance through 500 hours of accelerated weathering. The techno-economic model projects positive return on investment within 18 months for large-scale pharmaceutical distributor adoption in South West Nigeria. Keywords: thermochromic polymer, intelligent packaging, cold chain, temperature indicator, pharmaceutical distribution