BIO ENG C118 Study Guide - Midterm Guide: Sodium Chloride, Dlvo Theory, Viscoelasticity
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Please answer all of the questions clearly and box your final answer. physical constants appear at the end of the exam. Name: poly(l-lactide) is a semi-crystalline biodegradable polymer that has found widespread use in medical devices requiring strength (e. g. , sutures, fracture fixation pins, etc Yoo assume the maxwell element can satisfactorily describe th~ viscoelastic behavior of the polymer. (25pts. ) a. For the maxwell element, derive an expression for the stress-relaxation experiment describing stress as a function of time. From your expression draw a graph of stress vs. time and define the relaxation time (a) and indicate where it occurs on your graph. b. You decide to heat treat the material to dramatically increase ii. by a factor of 10. Msfjbioe cl18: you are given two materials to evaluate for implantable biomedical devices. Examination of proteins bound to the materials surface indicates that they were responsible for the poor performance.
