A two-dimensional IR correlation spectroscopic study of the conformational changes in syndiotactic polypropylene during crystallization

Abstract

The conformational changes of syndiotactic polypropylene (sPP) during melting and isothermal crystallization processes were studied by infrared (IR) and two-dimensional (2D) correlation analysis. The band at 963 cm À1 is assigned to the contribution of the amorphous component, and the band at 978 cm À1 is assigned to a shorter helical conformational length than the bands at 867 and 812 cm À1 , which are related to crystalline helical conformation. The difference spectra and 2D correlation spectra analysis of the crystallization process indicated that the changes in these regular bands occur in rapid sequence, which is not easily detected by conventional IR spectroscopy. It was found that the absorption intensity of the band at 963 cm À1 increases earlier than that of the band at 978 cm À1 , as well as of the bands at 867 and 812 cm À1 . The results suggest that the partial chains among the amorphous component change in conformation first, then the sPP chains adjust their local conformations to form short helical conformations and finally crystallization occurs.

Ductile tear behavior of multilayered polypropylene homopolymer/ethylene 1‐octene copolymer sheets

“…Therefore, it is necessary to study the crystallization properties of HPP in the HPP/POE systems. In recent years, the Fourier transform infrared spectroscopy (FTIR), a powerful method that is sensitive to chain conformations of crystalline region and amorphous region, has been applied to study the molecular structure and conformational adjustments of semicrystalline polymers . However, the data obtained by the traditional FTIR analytical methods was static, and could result in the loss of some significant information on conformational changes during the melting and crystallization processes of polymers.…”

Two-dimensional correlation spectroscopy in polymer study

“…Various polymer systems, such as block copolymers (Kim et al, 2006b; Jia et al, 2010; Jin et al, 2011), biodegradable polymers (Guo et al, 2011; Unger et al, 2011; Ando et al, 2012; Hoshina et al, 2012, 2014; Wang et al, 2014), conducting polymer (Hong et al, 2005; Grzeszczuk et al, 2013), liquid crystals (Tang et al, 2010; Cheng et al, 2011), polymer blends (Oh et al, 2009; Unger et al, 2009, 2011; Jelèić et al, 2010; Popescu and Vasile, 2010, 2011; Kuo and Liu, 2011), and polymer nanocomposites (Huang et al, 2009; Huang and Kuo, 2010; Peng et al, 2010; Ando et al, 2012; Qu et al, 2012), etc., are analyzed by 2DCOS. Detailed information of polymers for polymerization (Izawa et al, 2001; Hong et al, 2005; Huang and Kuo, 2010; Qu et al, 2012; Noda, 2014d; Seo et al, 2014), melting behavior (Unger et al, 2009; Peng et al, 2010; Popescu and Vasile, 2010), crystallization (Huang et al, 2009; Zheng et al, 2010; Guo et al, 2011; Unger et al, 2011; Ando et al, 2012; Hoshina et al, 2012, 2014; Chai et al, 2013; Wang et al, 2013, 2014), gelation (Wang and Wu, 2011; Su et al, 2012; Park et al, 2013), photoreaction (Lee et al, 2010, 2012), hydration (Lai and Wu, 2013), sorption/desorption processes (Musto et al, 2011; Lai and Wu, 2013; Galizia et al, 2014), and phase transition/separation (Kim et al, 2006b; Cheng et al, 2011; Kuo and Liu, 2011; Hou et al, 2014), etc., which are undergoing under the influence of applied external perturbation, are obtained by 2DCOS. 2DCOS probes with various analytical techniques, such as IR, near-IR (NIR), Raman, X-ray, UV-Vis, THz, NMR spectroscopies, and even chromatography, have been successfully applied in polymer studies.…”

“…IR spectroscopy is the most common analytical probes used in 2DCOS (Kim et al, 2006b; Cerdà-Costa et al, 2009; Huang et al, 2009; Unger et al, 2009, 2011; Del Río et al, 2010; Huang and Kuo, 2010; Jelèić et al, 2010; Jia et al, 2010; Lee et al, 2010, 2012; Peng et al, 2010; Popescu and Vasile, 2010, 2011; Zheng et al, 2010; Cheng et al, 2011; Jin et al, 2011; Kuo and Liu, 2011; Musto et al, 2011; Quaroni et al, 2011; Wang and Wu, 2011; Zhang et al, 2011; Ando et al, 2012; Qu et al, 2012; Su et al, 2012; Wu et al, 2012; Chai et al, 2013; Lai and Wu, 2013; Park et al, 2013; Shinzawa et al, 2013; Wang et al, 2013, 2014; Galizia et al, 2014; Hou et al, 2014; Noda, 2014c; Seo et al, 2014). The most popularly applied external perturbation in 2DCOS is temperature (Kim et al, 2006b; Unger et al, 2009, 2011; Jia et al, 2010; Peng et al, 2010; Popescu and Vasile, 2010; Tang et al, 2010; Zheng et al, 2010; Cheng et al, 2011; Wang and Wu, 2011; Pazderka and Kopecký Jr, 2012; Chai et al, 2013; Li et al, 2013; Wang et al, 2013, 2014; Hoshina et al, 2014; Hou et al, 2014; Seo et al, 2014). Applications of 2DCOS in investigations of intriguing properties of polymer system measured by different types of analytical probes has been substantially increased (Izawa et al, 2001; Hong et al, 2005; Kim et al, 2006b; Jiang and Wu, 2008; Huang et al, 2009; Oh et al, 2009; Unger et al, 2009, 2011; Del Río et al, 2010; Huang and Kuo, 2010; Jelèić et al, 2010; Jia et al, 2010; Lee et al, 2010, 2012; Peng et al, 2010; Popescu and Vasile, …”

“…The most popularly applied external perturbation in 2DCOS is temperature (Kim et al, 2006b; Unger et al, 2009, 2011; Jia et al, 2010; Peng et al, 2010; Popescu and Vasile, 2010; Tang et al, 2010; Zheng et al, 2010; Cheng et al, 2011; Wang and Wu, 2011; Pazderka and Kopecký Jr, 2012; Chai et al, 2013; Li et al, 2013; Wang et al, 2013, 2014; Hoshina et al, 2014; Hou et al, 2014; Seo et al, 2014). Applications of 2DCOS in investigations of intriguing properties of polymer system measured by different types of analytical probes has been substantially increased (Izawa et al, 2001; Hong et al, 2005; Kim et al, 2006b; Jiang and Wu, 2008; Huang et al, 2009; Oh et al, 2009; Unger et al, 2009, 2011; Del Río et al, 2010; Huang and Kuo, 2010; Jelèić et al, 2010; Jia et al, 2010; Lee et al, 2010, 2012; Peng et al, 2010; Popescu and Vasile, 2010, 2011; Radice et al, 2010; Tang et al, 2010; Zheng et al, 2010; Cheng et al, 2011; Guo et al, 2011; Jin et al, 2011; Kuo and Liu, 2011; Ma et al, 2011; Wang and Wu, 2011; Zhang et al, 2011; Ando et al, 2012; Hoshina et al, 2012, 2014; Qu et al, 2012; Su et al, 2012; Wu et al, 2012; Zhong et al, 2012; Chai et al, 2013; Grzeszczuk et al, 2013; Lai and Wu, 2013; Park et al, 2013; Shinzawa et al, 2013; Wang et al, 2013, 2014; Hou et al, 2014; Noda, 2014c,d; Seo et al, 2014). Generalized 2D correlation spectra has notable advantages: examination of inter- or intra-molecular interactions and determination of the sequential order of events, which is hardly depicted in conventional spectroscopy.…”

Crystallization Behavior of Poly(3‐hydroxybutyrate) (PHB), Poly(ε‐caprolactone) (PCL) and Their Blend (50:50 wt.%) Studied by 2D FT‐IR Correlation Spectroscopy

“…[1][2][3][4][5] However, the understanding of the crystallization process of polymers based on the knowledge of the molecular mobility controlling the transformation is still insufficient. In general, the formation of an ordered structure during the crystallization of polymer domains depends on the crystallization conditions.…”