A protocol is described to assess self-healing of crack damage in a polymer coating deposited on a substrate containing a microvascular network. The bio-inspired coating/substrate design delivers healing agent to cracks in the coating via a three-dimensional microvascular network embedded in the substrate. Through capillary action, monomer flows from the network channels into the crack plane wh...

Blends of poly(hydroxy ester ether) (PHEE), a recently developed bisphenol A ether-based synthetic biodegradable thermoplastic polymer, with a soybean protein isolate and two hydrolyzed wheat glutens were studied. Blends of the proteins with PHEE were produced from 20 to 70% by weight of protein content. Young’s moduli of the protein/PHEE blends fall in the range of 0.8–1.5 GPa with tensile str...

Cracking in Silicon solar cells is an important factor for the electrical power-loss of photovoltaic modules. Simple geometrical criteria identifying the amount of inactive cell areas depending on the position of cracks with respect to the main electric conductors have been proposed in the literature to predict worst case scenarios. Here we present an experimental study based on the electrolumi...

Owing to the very brittle nature of tellurium powder, nanoscopic grains with an average size of 4.8 ± 0.8 nm were produced by dry vibration milling technique using a mixer/mill apparatus. A novel material was obtained by binding the nanosized tellurium grains with poly(methyl methacrylate) (PMMA) polymer. The morphology, elemental composition, and structural and optical properties of Te/PMMA fi...

IMPACT RESISTANT GLASSY POLYMERS: PRE-STRESS AND MODE II FRACTURE FEBRUARY 2013 JARED STEVEN ARCHER B.S., WESTERN WASHINGTON UNIVERSITY M.S., UNIVERSITY OF MASSACHUSETTS AMHERST Ph.D., UNIVERSITY OF MASSACHUSETTS AMHERST Directed by: Professor Alan J. Lesser Model glassy polymers, polymethyl methacrylate (PMMA) and polycarbonate (PC) are used to experimentally probe several aspects of polymer f...

Copolymers of n-hexyl and allyl isocyanates were successfully synthesized using an organotitanium(IV) catalyst initiated polymerization. Viscosity measurements indicated that molecular weight increased with decrease in monomer/initiator ratio. Monomer reactivity ratios were calculated using the copolymer composition equation, and the resulting values indicated relative randomness in the copolym...

Wet starch cracks when it dries inhomogeneously, while hot glass cracks when it cools non-uniformly. In both cases, differential shrinkage induced by drying/cooling from the surface causes superficial cracks to grow perpendicular to the surface in different patterns. In contrast with these observations of bulk cracking in brittle materials, when a soft and homogeneously swollen polymer gel drie...

Polymers reinforced with high performance fibres are successfully replacing metal alloys in lightweight aircraft structures. A critical factor in structural design is the resistance of a structure to progressive damage which develops during its service time. The brittle nature of matrix cracking is the main source of composite failure initiating ply delamination and fibre to matrix debonding. B...