A spectrophotometric method for estimation of titanium alkoxide, a catalytically active form of titanium in oligomer/ polymers. (June 2020)

• Record Type: Journal Article
• Authors: Sattaiah Naidu, K; Kate, Abhijeet S.; Kshirsagar, Vikas; Ganeshan, R.; Gunale, Tukaram; Zhou, Bing; Anapat, Samir; Sulub, Yusuf; Kumar, Arun; Rao, Narayana
• Is Part Of: Polymer testing. Volume 86(2020)
• Publication Date: 2020-06
• Subjects: Spectrophotometric method -- Titanium cresolate -- Titanium alkoxide -- Titanium tetra-isopropoxide -- Polybutylene terephthalate; Polymers -- Testing -- Periodicals; Polymères -- Tests -- Périodiques; 620.1920287
• DOI: 10.1016/j.polymertesting.2020.106446
• Languages: English
• ISSNs: 0142-9418

Abstract

Abstract: A spectrophotometric method was developed for the selective estimation of titanium in alkoxide form in the presence of TiO2 . Polymers like polybutylene terephthalate have been synthesized by using homogeneous catalyst such as titanium tetra-isopropoxide (TTIP). These types of catalysts are susceptible to moisture and convert to inactive TiO2. Hence, it is essential to have analytical method for selective estimation of alkoxide form of titanium. In this study, we have used O-cresol to convert TTIP to tetra O- cresyl titanate, a colored compound, which was quantitatively analyzed by spectrophotometric technique. Polymer matrix was used in standard solution to compensate the effect of matrix during UV-VIS measurements. Method validation was successfully carried out for linearity, reproducibility, recovery, specificity and the observed acceptable results as per ICH guidelines. 2-sample t -test was performed to check the variation observed between two analysts and the observed p-value indicated the results were statistically similar to each other. Mechanism of color formation was established by synthesis of colored complex called tetra O-cresyl titanate. The structure was supported by ICP, CHNS and NMR analysis. The method is simple and easy to implement at manufacturing plant for initial monitoring of active catalyst concentration in polymer/oligomer samples. Highlights: A spectrophotometric method was developed for the selective estimation of titanium in alkoxide form in the presence of TiO2 . Mechanism of color formation was established by synthesis of colored complex called tetra O-cresyl titanate. Method was implemented on other metal isopropoxides such as Zr (IV), Sn (IV), and Ge (IV) and observed that only as TTIP gave colored solution after reaction with O-cresol. Results and experimental observations infers that method could be extrapolated to any titanium alkoxide catalysts.