Enthalpy Recovery after Carbon Dioxide Jumps G. B. McKenna, Texas Tech University, DMR-0307084

1. Enthalpy Recovery after Carbon Dioxide JumpsG. B. McKenna, Texas Tech University, DMR-0307084 • During the past year great progress has been made in the development of experimental methods to measure enthalpy recovery in polymer glasses after CO2 -jumps. • Completed construction of the pressure apparatus needed to do such experiments in a Setaram C80 calorimeter. (Figure 1). • Performed the first experiments demonstrating memory in enthalpy recovery after temperature jumps.(Figure 2). • Performed the first experiments of intrinsic isopiestics, asymmetry of approach and memory effects after CO2 –jumps.(Figure 3, intrinsic isopiestic only). • These results are currently being analyzed in the context of prior findings from this project that Temperature-glasses and Concentration-glasses are fundamentally different Figure 1. Schematic of pressure capable Setaram C80 calorimeter for CO2 –jumps in thin polymer films. Figure 3. Intrinsic isopiestics for PS Subsequent to single-step down jump in CO2 pressure. Figure 2. Memory effect for PS subsequent to two-step temperature jump

2. Broad Accomplishments: June 2006-June 2006NSF Grant DMR-0307084 • Education and Outreach • Project results presented at national and international meetings • Gordon Research Conference on Elastomers, Networks and Gels, July 2005 (poster by L. Banda, graduate student) • ENSMA, Poitiers, France, December 2005 (invited seminar by G.B. McKenna, PI) • American Physical Society, March Meeting, 2006 (oral presentation by L. Banda, graduate student) • Society of Plastics Engineers ANTEC in May 2006 (oral presentation by L. Banda, graduate student). • Chinese Academy of Sciences, Beijing, China, June 2006 (oral presentation by G.B. McKenna, PI) • Project results presented at one regional meeting • Society of Plastics Engineers Polyolefins Conference, Feb. 2006 (poster L. Banda, graduate student) • Society of Plastics Engineers Polyolefins Conference, Feb. 2006 (poster by S. Kollengodu-Subramanian, awarded honorable mention prize) • NATEX, April 2006 (posters by L. Banda and S. Kollengodu-Subramanian, graduate students) • PhD students supported or partially supported. • Yong Zheng, Received Ph.D. in December 2003. • Xiangfu Shi, received Ph.D. in December 2004. • Anny Flory, received Ph.D. in December 2004. • Lameck Banda, current student, expected to defend thesis July 2006. • Shankar Kollengodu-Subramanian, current student, expected to defend thesis fall 2007. • Publications • -6 manuscripts published (Polymer, 45, 5629-5634 (2004);J. Phys.: Condensed Matter, 17, R461-R524 (2005); Phys. Rev. Lett., 94, 157801-1-157801-4 (2005);J. Chem. Phys. 122, 114501-1-114501-6 (2005)); J. Polymer Sci. Part B. Polymer Phys. Ed., 44, 801-814 (2006); Phys. Rev. B., 73, 014203-1-014203-10 (2006). • -5 proceedings publications • -1 manuscript in review (J. Polym. Sci. Part B. Polymer Physics Ed..)