An implantable medical article as well as an implantable fiber which is particularly useful for medical implants is disclosed. The fiber includes comprises a first component formed from a substantially resorbable material and a second component formed from a fiber-forming polymer.

Implantable fibers and medical articles

Infrared (IR) thermal analysis was used to study the extent, distribution, and the thermal behavior of hydorgen bonding in MDI-based segmented polyurethane elastomers. Two series of polyurethane elastomers were studied; one was based on a polytetrahydrofuran soft segment (ET series), while the second was based on a poly(tetramethylene adipate) soft segment (ES series). The hard segment in these materials was formed form p, p′-diphenylmethane diisocyanate (MDI) extended with butanediol. Bonded and free NH and C=O infrared absorbances were resolved as a function of temperature using a nonlinear least squares analysis for the fitting of Gaussian curve shapes. Results of this analysis revealed that at room temperature, about 80% of the NH groups in the ET and ES polyurethanes formed hydrogen bonds. In the ET polyurethanes, about 65% of the urethane carbonyls were hydrogen-bonded at room temperature. The extent of interurethane hydrogen bonding was found to be higher in the materials having better pha...

Infrared thermal analysis of polyurethane block polymers

Glass Transition Temperatures of Polymers

An infrared thermal analysis technique was used to measure the enthalpy of dissociation of hydrogen bonds in various polyamides and to test the influence of the type of nylon, annealing time, and moisture content on the strength of hydrogen bonding. Nearly all of the NH groups were found to be hydrogen bonded at room temperature for every nylon tested. Enthalpies of dissociation ranged from about 8–12 kcal/mole. Tensile tests were also performed to determine the effects of the same variables on Young’s modulus of the polyamides. The results show that while the enthalpy of dissociation of the hydrogen bonds was not significantly changed by the type of nylon or any of the tested variables, the modulus was strongly affected by several of the treatments. Since factors which do not affect the strength of hydrogen bonding do have a large effect on the modulus and failure mode, it may be inferred that hydrogen bonding does not play a primary role in determining the mechanical properties of polyamides.

Hydrogen bonding in polyamides

A new idea to understand the macromolecular motion occurring along the thermal relaxations of polystyrene (PS) and PS–barium titanate composites is proposed. Detailed analysis of PS infrared bands provides a better knowledge of the factors affecting polymer dynamics. Average spectral positions and integrated absorbance of bands in the region of C–H out-of-plane vibrations showed a continuous decrease with temperature, whereas those in the region of aliphatic and aromatic C–H stretching vibrations showed the sharpest changes with temperature. Relaxation temperatures were determined from the changes observed in the band wavenumber or area with temperature. These results were attributed to changes in the distribution of the phenyl π-electron cloud, causing important dipole moment variations in the different vibration modes when the thermal transitions are taking place. Finally, although the presence of BaTiO3 particles does not seem to exert any specific effect on the PS dynamics in the glassy state, the Curie transition of these particles might induce a kind of confinement effect observable by FTIR.

New molecular-scale information on polystyrene dynamics in PS and PS–BaTiO3 composites from FTIR spectroscopy

A surprising improvement in dye-lightfastness of dyed nylon automotive fabrics is achieved by a combination of a copper salt and of an oxanilide light stabilizer. The oxanilide is effective with a surprisingly broad range of copper derivatives. Both the copper and the oxanilide may conveniently be applied from the dyebath, or, surprisingly, the copper provides improvements even if melt-spun into the fiber.

Nylon fabrics with cupric salt and oxanilide for improved dye-lightfastness

A plant-growing nonwoven mat comprising a layer of hollow synthetic organic fibers having in their lumens water-soluble plant adjuvants, such as plant nutrients, fungicides, algaecides, weed killers, pesticides, and the like, provides slow release of the adjuvants to enhance and protect plant growth.

Fibrous mat for growing plants

Infrared bands in the 900–1100 cm−1 region are sensitive to thermal energy. These bands can result from intermolecular coupling, producing the crystal lattice, or from intramolecular coupling of the various atomic groups in a regular helix or coiled chain. In either case an increase in temperature will disrupt the coupling mode, resulting in a form of structural relaxation and a reduction in the integrated absorbance. It is proposed that the temperature at which the peak areas begin to decrease be assigned as the Tg. This is measured by continuously scanning a selected peak in the infrared spectrum of a polymer film while it is heated at a rate of about 1°C/min. Using this technique polyamides (nos. 6,66, and 610) exhibited transitions in the 30–50°C range, and by studying the increase in the free NH region (3440 cm−1) of nylon 66 two other transitions were detected at 80 and 137°C; the latter represents a change in the nylon 66 crystal state. An amorphous film of poly(ethylene terephthalate) displayed a transition at 58–68°C (Tg) and at 85°C, which is the crystallization temperature. Films of poly(vinyl acetate) and polystyrene exhibited transitions at 25–37°C and at 70°C, respectively.

Detection of polymer transition temperatures by infrared absorption spectrometry

Process for producing producer-colored nylon fibers which are stain-resistant to acid dyes are made by adding pigment to nylon copolymers containing 0.25-4.0 percent by weight of an aromatic sulfonate or an alkali metal salt thereof.

Process for producing stain-resistant, pigmented nylon fibers

A synthetic polyamide filament is composed of an acid-dyeable polyamide core surrounded by a basic-dyeable polyamide sheath containing aromatic sulfonate groups. At a normal dyeing pH of 4-7 the core accepts leveling acid dyes but not reserving acid or basic dyes. The sheath accepts leveling and nonleveling basic dyes. Versatility in cross-dye styling when such filaments are combined with acid-dyeable and basic-dyeable monocomponent filaments is demonstrated.

Polyamide filaments with a basic-dyeable sheath and an acid-dyeable core and dyeing process therefor

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