The Effects Of Triphenylphosphate and Recorcinolbis(Diphenylphosphate) on the Thermal Degradation Of Polycarbonate in Air

The thermal degradation of polycarbonate/triphenylphosphate (PC/TPP) and PC/resocinolbis(diphenylphosphate) (PC/RDP) in air has been studied using TGA/FTIR and GC/MS. In PC/phosphate blends, the phosphate stabilizes the carbonate group of polycarbonate from alcoholysis between the alcohol products of polycarbonate degradation and the carbonate linkage. Thus, the evolution of bisphenol A, which is mainly produced via hydrolysis/alcoholysis of the carbonate linkage, is significantly reduced, while, the evolution of various alkylphenols and diarylcarbonates increases. The bonds that are broken first in the thermal degradation of both the carbonate and isopropylidene linkages of polycarbonate are the weakest bonds in each, when a phosphate is present. Triphenylphosphate and resocinolbis(diphenyl-phosphate), even though they exhibit a significant difference in their volatilization temperature, appear to play a similar role in the degradation pathway of polycarbonate

Transparent polymeric laminates

Laminate prepared from epoxy-boroxine and phenolphthalein polycarbonate has high mechanical strength at elevated temperature and is resistant to impact, fire, and high-energy thermal radiation. Polycarbonate is prepared by reaction of phenolphthalein with phosgene in presence of amine catalyst and immiscible organic solvent phase

Slow crack growth in polycarbonate films

We study experimentally the slow growth of a single crack in polycarbonate films submitted to uniaxial and constant imposed stress. The specificity of fracture in polycarbonate films is the appearance of flame shaped macroscopic process zones at the tips of the crack. Supported by an experimental study of the mechanical properties of polycarbonate films, an analysis of the stress dependence of the mean ratio between the process zone and crack lengths, during the crack growth, show a quantitative agreement with the Dugdale-Barenblatt model of the plastic process zone. We find that the fracture growth curves obey strong scaling properties that lead to a well defined growth master curve

The Thermal degradation of Bisphenol A Polycarbonate in Air

The thermal degradation of polycarbonate in air was studied as a function of mass loss using TGA/FTIR, GC/MS and LC/MS. In the main degradation region, 480–560 °C, the assigned structures of smaller molecules and linear molecules that evolved in air were very similar to those obtained from the degradation in nitrogen; the degradation of polycarbonate follows chain scission of the isopropylidene linkage, in agreement with the bond dissociation energies, and hydrolysis/alcoholysis of carbonate linkage. Compared to the degradation in nitrogen, some differences were observed primarily in the beginning stage of degradation. Oxygen may facilitate branching as well as radical formation via the formation of peroxides. These peroxides undergo further dissociations and combinations, producing aldehydes, ketones and some branched structures, mainly in the beginning stage of degradation. It is speculated that the intermediate char formed in the beginning due to branching reactions of peroxide interferes with the mass transfer through the surface of degrading polycarbonate in the main degradation. Thus, even though the mass loss begins earlier in air, a slower mass loss rate is observed

Helmet assembly and latch means therefor Patent

Transparent polycarbonate resin, shell helmet and latch design for high altitude and space fligh

Constitutive model for plasticity in an amorphous polycarbonate

A constitutive model for describing the mechanical response of an amorphous glassy polycarbonate is proposed. The model is based on an isotropic elastic phase surrounded by an SO(3) continuum of plastic phases onto which the elastic phase can collapse under strain. An approximate relaxed energy is developed for this model on the basis of physical considerations and extensive numerical testing, and it is shown that it corresponds to an ideal elastic-plastic behavior. Kinetic effects are introduced as rate-independent viscoplasticity, and a comparison with experimental data is presented, showing that the proposed model is able to capture the main features of the plastic behavior of amophous glassy polycarbonate

Capacitor failure rate determination test Quarterly progress report, period ending Dec. 1965

Life testing and reliability engineering of film-foil polycarbonate capacitors for static convertors and inverter

Thermocouple-flexible cable connector insulator is highly reliable

Plastic /polycarbonate/ insulator improves thermocouple reliability in test operations. The insulator is molded in half sections, assembled mechanically and eliminates electrical shorting

Helmet of a laminate construction of polycarbonate and polysulfone polymeric material

An article of laminate construction is disclosed which is comprised of an underlayer of polycarbonate polymer material to which is applied a chemically resistant outer layer of polysulfone. The layers which are joined by compression-heat molding, are molded to form the shape of a body protective shell such as a space helmet comprising a shell of polycarbonate, polysulfone laminate construction attached at its open end to a sealing ring adapted for connection to a space suit. The front portion of the shell provides a transparent visor for the helmet. An outer visor of polycarbonate polysulfone laminate construction is pivotally mounted to the sealing ring for covering the transparent visor portion of the shell during extravehicular activities. The polycarbonate under layer of the outer visor is coated on its inner surface with a vacuum deposit of gold to provide additional thermal radiation resistance