Experimental and simulation studies of gas sorption processes in polycarbonate films

This work reports the experimental isotherms describing the concentration of oxygen and nitrogen in poly(bisphenol A carbonate-co-4,4′-(3,3,5-trimethylcyclohexylidene) diphenol carbonate) vs pressure, at 30 °C. The solubility coefficients are interpreted in terms of the Flory-Huggins theory, obtaining reasonable values for the enthalpic polymer-gas parameter. A new method is outlined to simulate the probabilities of inserting/removing a gas molecule in a host matrix already containing n molecules of gas. The simulated isotherms representing the pressure dependence of the concentration exhibit the same pattern as those experimentally obtained.     

Thermal and mechanical properties of polyhedral oligomeric silsesquioxane (POSS)/polycarbonate composites

A series of composite materials were produced incorporating polyhedral oligomeric silsesquioxane (POSS) derivatives into polycarbonate (PC), by melt blending. Significant differences in compatibility were observed depending on the nano-scale filler's specific structure: trisilanol POSS molecules generally provided better compatibility with PC than fully-saturated cage structures, and phenyl-substituted POSS grades were shown to be more compatible with PC than fillers with other functional groups. Trisilanolphenyl-POSS/PC composites possess the best overall performance among the POSS materials tested. The high compatibility between the trisilanolphenyl-POSS and polycarbonate matrix results in generation of transparent samples up to 5 wt% POSS content. Slightly enhanced mechanical properties including tensile and dynamic mechanical modulus are observed with the increase of trisilanolphenyl-POSS loading at the cost of decreasing ductility of the nanocomposites. Importantly, upon orientation of the PC/POSS nanocomposite, crystallization of POSS within the oriented material results—this observation is consistent with a growing number of observations which suggest that ‘bottom-up’ formation of structures incorporating multiple POSS cages result from orientation of these nanocomposites, and that the hybrid organic-inorganic inclusions may be at the heart of observed nano-scale reinforcement.     

聚碳酸酯的生产及市场

介绍了聚碳酸酯生产工艺技术的进展，综述了国内外聚碳酸酯的生产及市场情况，对我国聚碳酸酯的市场发展趋势进行了分析和预测，并对我国聚碳酸酯工业的发展提出了几点建议。     

聚碳酸酯的吹塑成型

简介聚碳酸酯吹塑容器的特性与用途,着重分析其吹塑(包括挤出吹塑、共挤吹塑和注射吹塑)成型的机械(螺杆、机筒、型坯机头与吹塑模具)设计要点及工艺条件。     

Diluent effects on carbonate mobility in bisphenol-A polycarbonate in the solid state

The effect of miscible low molecular weight additives on the mobility of the carbonate group in bisphenol-A polycarbonate (BPAPC) has been studied using n.m.r. and dielectric relaxation experiments in the solid state. Proton-enhanced dipolar-decoupled carbon-13 n.m.r. spectra of BPAPC, isotopically enriched at the carbonate position, are obtained without magic-angle sample spinning. The resolved chemical shift anisotropy allows study of nuclear spin relaxation for the carbonate groups in the polymer that have different orientations relative to the static magnetic field in the laboratory frame. The spin-lattice relaxation time in the rotating frame (T_1?) is measured at a motional-probe frequency of 50 kHz for the undiluted polymer and for BPAPC-diluent blends containing either dibutylphthalate or dinitrobiphenyl. The T_1? exhibits some dependence on orientation in all systems studied. In the blend containing dibutylphthalate (DBP), T_1? is decreased by a factor of two for all orientations of the carbonate group. This implies that DBP substantially increases the spectral density of 50 kHz motions in the carbonate region of the polymer at ambient temperature. In contrast, dinitrobiphenyl does not significantly alter the Fourier component of thermal fluctuations at 50 kHz. Dielectric relaxation measurements at 10 kHz reveal that the primary (T_g) and secondary (β) motional processes in BPAPC are affected by low molecular weight additives. An intermediate relaxation process appears in the temperature interval between the glass transition temperature (T_g) and the sub-T_g β-relaxation (T_β) in the polymer-diluent blends. The n.m.r. spin-lattice relaxation rate in the rotating frame, T^?1_1?, correlates well with the relative magnitude of the dielectric dissipation factor (tan δ_ε) between T_g and T_β.     

PC／PA1010共混物的热行为

利用热失重、微分热失重和显示扫描量热法研究了聚碳酸酯／尼龙１０１０共混物的热行为和解降解过程。结果表明：共混物在６００℃以下分两步降解，降解温度随尼龙１０１０用量增加有下降趋势；共混物的熔点随尼龙１０１０用量增加而升高。     

Chemical reactions,thermal and mechanical properties of epoxy — Polycarbonate blends cured with aromatic amines

Bisphenol-A polycarbonate (PC) has been incorporated into epoxy resin cured with 4,4-diaminodiphenyl sulphone (DDS) and 4,4'-diaminodiphenyl methane (DDM). IR spectra reveal that transesterification and transamidation occur between the carbonate group of PC and the hydroxyl group of cured epoxy resin for the DDM-cured system, and that only transesterification occurs for the DDS-cured system. Scanning electron micrographs (SEM) show no evidence of phase separation in these cured systems, which is an indication of full miscibility between the bisphenol-A monomers and PC-oligomers with the copolymer network. The mechanical strength and glass transition temperature (T_g) fluctuate with PC content, whereas the flexural modulus shows a steadily increasing tendency.     

Polycarbonate and co-continuous polycarbonate/ABS blends: influence of specimen thickness

The influence of specimen thickness on the fracture behaviour of polycarbonate (PC) and co-continuous PC/ABS (50/50) blends was studied in single edge notch tensile tests at 1 m/s and different temperatures (−80 to 130 °C). Specimen thickness ranged from 0.1 to 8 mm. In the co-continuous PC/ABS blends the rubber concentration in the ABS was 0, 15 and 30 wt%. The change in fracture toughness was typified by the change in brittle-to-ductile transition temperature (T_bd).T_bd of pure PC depended strongly on specimen thickness, leading to very low transition temperatures for thin PC specimens. PC/ABS 0%, a 50/50 blend of PC and SAN (i.e. ABS without polybutadiene (PB)), was a brittle blend and showed a very high T_bd close to the T_g of SAN. T_bd did not seem to be influenced by specimen thickness. PC/ABS blends with 15 and 30% PB in ABS showed improved T_bd compared to PC/SAN and PC, indicating effective rubber toughening. T_bd decreased with decreasing thickness for PC/ABS specimens thicker than 1.5 mm. However, T_bd increased with decreasing thickness for specimens below 1.5 mm thickness. In thin specimens, the rubber-filled blend is less effective rubber toughening. The plane strain stress condition needed for rubber cavitation is apparently not present in thin specimens.     

相容剂及其在PC/ABS合金中的应用

采用水相悬浮聚合法合成了SAN-g-MAH、SAN-g-MMA、SAN-g-GMA3种相容剂,比较了3种相容剂对PC/ABS合金的增容效果,着重研究了工艺条件对接枝率的影响及相容剂用量对合金力学性能的影响。结果表明,相容剂的最大接枝率可达5.76%,添加相容剂后,PC/ABS合金的力学性能有明显提高,拉伸强度和缺口冲击强度分别可达61.91MPa和10.12kJ/m2。