Some new aspects of the crystallization of bisphenol‐A polycarbonate

Abstract

This paper concerns the action of plasticizers and nucleating agents on the crystallization of bisphenol‐A polycarbonate. The influence of plasticizers is to increase the rate of crystallization to a great extent using 10 percent of a plasticizer such as trimellitic acid, tridecyloctyl ester. The influence of nucleating substances on plasticized and undiluted polycarbonate is investigated. A large number of substances have been found capable of nucleating polycarbonate crystallization. The un‐plasticized semi‐crystalline polycarbonate is characterized by a much higher melting point (300°C) than the plasticized semi‐crystalline systems (210–245°C). The stability of bisphenol‐A polycarbonate in the presence of nucleating salts is also examined. We observe a substantial decrease in the molecular weight in the presence of a great number of nucleating substances. The modulus‐temperature curves of two semi‐crystalline polymers are reported in the last series of experiments.

Blends of polycarbonate and acrylic polymers: Crystallization of polycarbonate

“…This last point is illustrated, for instance, by the fact that low molecular weight components only slightly miscible with PC are more efficient in promoting crystallization than more miscible ones. 51,52 This is, for example, the case for plasticizers 40 : dichloromethane has a higher affinity for PC than acetone, but acetone is more efficient in promoting crystallization of PC.…”

Fourier transform infrared analysis of polycarbonate/epoxy mixtures cured with an aromatic amine

“…The change of morphology cizer. 56,58 When immersed in acetone, PC crystallizes at room temperature up to a 24% crystallingave some variations of the local environment of the absorbing groups and subsequently affected ity in only 24 h. In the present case, residual methylene chloride and the epoxy oligomer both the optical extinction coefficient of these groups. As a result, the data are more scattered and the facilitate the crystallization of PC.…”

“…Still, addition to the T g at 156ЊC, a small melting peak at 212ЊC was observed, a little lower than that of PC is capable of crystallization when annealed at temperatures between the T g and T m , although at pure PC, 235ЊC. 58 The presence of epoxy resin and the rapid increase of viscosity during cure rea strikingly slow rate. 56 It has been reported 57 that the annealing of very thin films (100 mm) sulted in the imperfection and smallness of PC crystallites, depressing the melting point of PC required 8 days at 190ЊC for the first crystallites to appear.…”

“…In principle, crystallization quired to develop 12% crystallinity at 190ЊC. 58 The time for crystallization can be greatly reduced depends on three characteristic temperatures: (1) the cure temperature (same as the crystallization through the addition of either a solvent or a plasti-5457 / 8E5C$$5457 07-14-98 15:20:22 polaa W: Poly Applied with the band parameters described in the previous article, 15 that is, a bandwidth (v 1/2 ) of 26 { 1 cm 01 and a 0.6 Gaussian shape for the peak 1776 cm 01 and a 13.0 { 0.5 cm 01 bandwidth with a Lorenzian shape for the peak 1766 cm 01 , the carbonyl peak was resolved into two peaks, corresponding to the carbonyl vibration in the amorphous and crystalline regions. The results are shown in Figure 8.…”

Effects of carbonate salts on crystallization kinetics and properties of recycled poly(ethylene terephthalate)

“…It has at normal mold temperatures. 4 The crystallizabeen reported 1,2 that the maximum radial growth tion rate can be increased by using high mold temof PET crystals is 10 mm/min, a growth rate which peratures (at least 130ЊC) attained by oil or elecis, indeed, very slow when compared, as an examtrical heating and longer mold cycles; these techple, to that of PE (5,000 mm/min). Crystallization niques present economic disadvantages 5 and kinetics of unmodified, reactor PET depend prioften yield finished parts of low crystallinity that marily on temperature, MW, catalyst residue, and are difficult to remove from the mold or brittle the presence of diethylene glycol formed during products with a coarse spherulitic structure.…”