To find out the molecular level changes in lac‐MF blends, occurring due to the effect of thermal stress on the blends at elevated temperature and at different intervals of baking time.
Films of lac‐MF blends, applied on tin panels were baked at 200°C for different time intervals. The baked films were examined by specular reflectance spectroscopy, as they were otherwise difficult to examine through conventional IR techniques, using KBr pellet method, due to their amorphous and tacky nature. The results obtained were compared and reported.
On baking the blends of lac‐MF resin at 200°C for different time intervals, cross‐polymerisation sets in via esterification and condensation. In addition to this, etherification may take place among different molecules of lac and MF resin. In terms of different physico‐chemical parameters, blends of 7:3 (w/w) lac:MF and of 1:1 (w/w) lac:MF were found to be better than blends of 3:7 (w/w) lac:MF, baked at 200°C for different time intervals.
Chemical researches on lac‐synthetic resin blends have been typically limited due to the complex nature of resins and also due to the lack of suitable modern tools and techniques. This has been solved using state‐of‐the‐art instrumentation and computational techniques, which may prove to be useful to industry and for research.
Lac and its blends retain their significance in diverse fields of applications, ranging from surface coatings and food applications, to the formulation of lacquers, varnishes and in the finishing industry. Findings made in this study could have significant application for such industries from an application point of view.
To date, there is no record of specular – reflectance and derivative spectrometric studies on lac‐synthetic resin blends. This paper represents the first attempt to obtain and correlate reflectance data on such blends. It also highlights the convenience of the method and the scope of sophisticated data analysis, including derivative spectrometry.
