A stretching apparatus with broad strain rate and temperature ranges for in-situ x-ray scattering measurements of polymers.

A stretching apparatus capable of conducting tensile tests over a broad strain rate range (10-3-250 s-1) and a wide temperature range (-75-250 °C) has been designed for polymeric materials, in particular the polymeric films. Specifically, this stretching apparatus can be combined with in situ ultrasmall-, small-, and wide-angle x-ray scattering (USAXS/SAXS/WAXS) measurements. The sample stretching is achieved through the synchronized rotation of rolls, powered by servo motors.

Multiscale Relaxation Behavior of Amorphous Plasticized Poly(vinyl butyral).

As a key component in laminated glass, plasticized polyvinyl butyral (PVB) interlayer is a kind of impact-resistant polymer material with high toughness. Recently, by using ultrasmall angle X-ray scattering (USAXS) technique, Stretch-induced phase-separated structure on the scale of hundreds of nanometers formed in plasticized PVB for the first time is reported. In this work, the multiscale relaxation behavior of plasticized PVB is further investigated.

Wrinkling and restabilization of a hyperelastic PDMS membrane at finite strain.

Wrinkles are commonly observed in uniaxially stretched hyperelastic membranes and eventually disappear with the increase of stretching. The widely used scheme at present assumes the material parameters to be empirical values and straightforwardly considers some constitutive models to explore the wrinkling and restabilization behavior. However, this simple treatment may cause deviation from experiment by ignoring the applicability of the models and the authenticity of the input parameters, prompting us to report based on realistic material parameters.

Manipulation of Chain Entanglement and Crystal Networks of Biodegradable Poly(butylene adipate--butylene terephthalate) During Film Blowing through the Addition of a Chain Extender: An In Situ Synchrotron Radiation X-ray Scattering Study.

One prerequisite for the large-scale application of biodegradable polymers is the manipulation of macroscopic performances of commercially available biopolymers during processing according to different real service requirements. Herein, the microstructural evolution of poly(butylene adipate--butylene terephthalate) (PBAT) modified by chain extender during film blowing was investigated by in situ synchrotron radiation X-ray scattering to unveil the origin of different performances. The chain dynamics difference induced by the chain extender was first characterized by the rheological measurement and H Multiple Quantum (MQ) NMR.