Equilibrium melting temperature and crystallization kinetics of α- and β′-PBN crystal forms

Shape Memory Tube Plug for Fine-control of Intraocular Pressure by Glaucoma Devices

As a standard approach to treating glaucoma, a silicone tube device is inserted into the eye to drain water and thereby lower the intraocular pressure (IOP). However, the fixed diameter of the tube often results in too much initial water drain. Suture-sheaving of the outer tube wall also leads to random IOP drops over time. In this study, self-expansion of the inner tube diameter was achieved by inserting a shape memory tube into the silicone tube. The difference in controlling small to large IOP drops before and after tube diameter expansion was demonstrated via computational modeling, a flow pumping system, and rabbit experiments.

Degradable Polymer Films Made from Poly(salicylic-acid-co-sebacic acid) and Poly(sebacic anhydride)/Poly(adipic anhydride) Blends: Degradation Kinetics and Use as Sacrificial Layers for Polymer Multilayer Systems

Two approaches to obtain fast-degrading polymer films based on poly(sebacic anhydride) (PSA) are presented, both of which target polymer films with a lower degree of crystallinity than pure PSA homopolymer: first, thin films were prepared from poly(adipic anhydride)/poly(sebacic anhydride) blends at different ratios, and second, films were made from the copolymer poly(salicylic acid-co-sebacic acid). These films are intended as sacrificial layers for self-regenerating functional coatings, for example to regenerate antimicrobial surface activity. The degradation kinetics of these films were analyzed by surface plasmon resonance spectroscopy (SPR). The results of the blends approach indicate that the blend degradation rate was accelerated only in the initial degradation phase (compared to PSA). The degradation kinetics study of the poly(salicylic-acid-co-sebacic acid) film shows that this copolymer degraded faster than poly(sebacic anhydride) initially, releasing antimicrobial salicylic acid in the process. However, its degradation rate slowed down at a mass loss > 60% and approached the PSA degradation curve at longer degradation times. When tested as sacrificial layer in self-regenerating antimicrobial polymer stacks, it was found that the degradation rate was too low for successful layer shedding.

Synthesis and controlled crystallization of in situ prepared poly(butylene-2,6-naphthalate) nanocomposites

The polymorphic nature of poly(butylene-2,6-naphthalate) (PBN) and the in situ prepared PBN-based nanocomposites was thoroughly evaluated.