The research aims to gain basic knowledge of polymer dynamics under large deformations. This task can be experimentally challenging due to finite size effects, i.e., the sample is never infinitely large, and free surface on the meniscus is often blamed for failure to demonstrate inherent constitutive behavior of polymer deformation. We made two essential improvements (see Fig. 1 and 2 on the right) over the previous experimental designs to eliminate any potential complications that could be due to presence of the edges during large deformation. The recently discovered phenomena in polymer dynamics under large deformation including elastic yielding, shear banding and wall slip have been found to occur in absence of any edge effects. These findings therefore pave the road for the future to reliably explore the intrinsic dynamic properties of entangled polymers. Several hundred billion pounds of polymer resins are produced each year worldwide. Plastic and rubber products are all made from these resins through processing. Our research outcome has the potential to allow these products (ranging from grocery bags, milk bottles to auto tires) to be made faster at a lower energy cost. Since a great deal of work has been done in the first year of this grant, resulting, so far, in nine publications in blue ribbon journals, we have to focus on discussing just two projects, one completed and the other still going. Exploring universal picture of yielding in entangled polymeric liquids under large deformation Shi-Qing Wang, University of Akron, DMR Fig. 1 illustrates the design strategy to prevent the free surface from undergoing failure when the sample between the small gap suffers sufficient strain at the observation point of the particle-tracking velocimetry. meniscus Fig. 2 sketches a new design of a shear rheometer involving rotation of the inner cylinder by a constant torque as well as a photo of this device. Here the aim is to have a sample wrapped close onto itself to eliminate meniscus along the shearing direction.

In the arena of broader impact, we have several areas to report: (A)Rob Misconin successfully completed his REU summer research. His data will contribute to at least one publications. (B)PI got invited to China in June 2009 to teach a short course (20 lecture hours) on the latest description of polymer dynamics and rheology, which was attended by over 100 from all over China. (C)Our research has drawn industrial attention from a largest petro- chemical company in the world, i.e., SINOPEC. This company wishes to collaborate with us to develop new products to meet the market demand. Please insert an image or group of images here to illustrate your broader impacts activities. If you need more space, you may reduce the adjacent textbox. Please use lettering that is clearly visible (i.e. not too small). Please include a brief figure caption. The group photo, with the undergrad REU student Rob Misconin in the black shirt. Having Rob in the lab for the summer gave the graduate students a chance to mentor and teacher new comers Exploring universal picture of yielding in entangled polymeric liquids under large deformation Shi-Qing Wang, University of Akron, DMR