Dr. Delmar Timm's research focuses on composite materials comprised of a polymeric matrix. Emphasis is directed at developing correlations between the resin's molecular structure and its physical performance. With thermosetting resins, polymeric molecules are characterized by their degree of polymerization, chemical composition, extent of chain branching, and degree of chain cross-linking. Theoretical modeling incorporates deterministic and stochastic methodologies. In one phase of the research, kinetic reaction studies are directed at the evaluation of reaction mechanism and rate constants. In a second phase, estimates of molecular structure are confirmed and incorporated into structure/property relationships. Tsai-Halpin correlations then couple matrix contributions with reinforcement properties and spatial orientation. In a third phase nondestructive evaluations are performed using nonobtrusive, embedded sensors. Using a numerically controlled machine, composite specimens are filament wound.
W. Chian and D. C. Timm, “Chemical/Mechanical Analysis of Anhydride-Cured Thermosetting Epoxys: DGEBA/NMA/BDMA”, Macromolecules 37(21), 8098 (2004).
W. Chian and D. C. Timm, “Kinetic Reaction Analysis of an Anhydride-Cured Thermoplastic Epoxy: PGE/NMA/BDMA”, Macromolecules 37 (21), 8091 (2004).
S. Choi, X. Liu, D. C. Timm, “Deterministic Solutions for a Step-growth Polymerization”, Macromol. Symp. 200, 271 (2003).
Tadros, RM; Noureddini, H; Timm, DC, Michaelis-Menten kinetics for enzymatic depolymerization of a linear polyester synthesized from z-protected glutamic acid, JOURNAL OF APPLIED POLYMER SCIENCE, 80 (4): 514-520 Apr 25 2001.
Akerlund, J; Harmeier, S; Pumphrey, J; Timm, DC; Brand, JI, Diketopiperazine-based polymers from common amino acids, JOURNAL OF APPLIED POLYMER SCIENCE, 78 (12): 2213-2218 Dec 13 2000