Static and Dynamic FT-IR Linear Dichroism Studies of Plasticization Effects in a Polyurethane Elastomer

Abstract

By combining FTIR data of plasticized Estane (a polyester polyurethane copolymer) subjected to mechanical deformation with spectral differences as a function of added plasticizer, insight into the physical role of plasticization is gained. For Estane, the orientation functions and dichroic difference data show that, in static stretching, the soft domains reach orientation saturation before the hard domains. With added plasticizer, hydrogen bonding to the hard segments is disrupted and the glass transition of the soft domain decreases, indicating that plasticizer remains solubilized in the soft domain. On the time scale of the static experiment, plasticization diminishes the ability of both domains to reorient, while the plasticizer itself does not orient. With added plasticizer, neither domain reaches orientation saturation during the prestretching process, and dynamic distortion results in a similar response from both domains. Bimodal bands in the dynamic data indicate that the strain applied on a rapid time scale (20 Hz) allows resolution of the components of differently oriented bands.

Rheooptical Fourier transform infrared spectroscopy of the deformation behavior in quenched and slow‐cooled isotactic polypropylene films

“…Early work by Stein and coworker, 6,7 Siesler,11,12 Hayes and coworkers, [13][14][15][16][17][18] and Zawada and coworkers 19,20 as well as recent work by Nakashima and coworkers, 21,22 Wang and coworkers, [23][24][25][26][27] and Pellerin and coworkers 28 -33 have explored the various aspects of the use of FTIR spectroscopy to characterize orientation in complex polymers. Noda et al 34 were the first to incorporate polarization modulation with dynamic sample perturbation for direct measurement of dynamic infrared linear dichroism (DIRLD).…”

DMA−FTIR Creep−Recovery Study of a Poly(ester urethane) Elastomer with Molecular-Level Viscoelastic Modeling

“…7,23,24 If the usual simplifying assumption is made that ψ, the angle between the polymer chain axis and each of the vibrational dipoles, is equal to either 0 or 90°, the equations for calculating the orientation function f simplify to the following forms:…”

Dynamic behavior of polymer films in the presence of plasticizers by using ATR-based dynamic compression modulation step-scan Fourier transform infrared spectroscopy, and 2D correlation analysis

“…These additives often affect physical properties of polymers. For example, addition of plasticizers to polymers have been known to decrease stress at break, increase strain at break, and decrease Young's modulus and glass transition of the polymers [5]. The presence or absence of these plasticizers may also affect polymer's microscopic structure, which in turn, changes the nature of molecular interactions between polymers and plasticizers.…”

“…The presence or absence of these plasticizers may also affect polymer's microscopic structure, which in turn, changes the nature of molecular interactions between polymers and plasticizers. However, relatively few detailed study concerning the dynamic molecular interactions between polymers and plasticizers has been reported [5,6]. A study of the effect of plasticization on polymer compression properties may provide an important insight about the molecular-level role played by the plasticizers in the polymeric system.…”