1. FR4 = this is a grade assigned for glass-reinforced epoxy laminate material. It a composite material composed of woven fiberglass cloth with an epoxy resin binder that is flame resistant. FR- stands for flame retardant. Epoxy resigns are chemical resistant polymer

2. Polyglycolic Acid (PGA) - is semi-crystalline polyester with good mechanical and degradative properties. PGA is biocompatible and in the body degrades via a hydrolysis reaction in which glycolic acid (GA) is the degradation product [1]. GA is decomposed in the carbohydrate cycle within the body, making PGA and some of its co-polymers very attractive for use in biomedical applications as sutures and as bone fixation devices in the form of pins, rods, plates and screws. Other applications of these materials include drug delivery carriers and scaffolds for cell culture

Properties

v Density, Completely Amorphous

v Density, Completely Crystalline

v b Lattice Constant

v Tensile Strength, Ultimate, Fiber

v Elongation at Break, Fiber

v Modulus of Elasticity, Fiber

v Heat of Fusion, Completely Crystalline

v Melting Point

v Glass Transition Temp, Tg

v Decomposition Temperature

Thanks for the answer. I know what FR4 is. I am just seeking the values for the materials peoperties listed in my questions