[2,7-Dimeth­oxy-8-(2-naphtho­yl)naphthalen-1-yl](naphthalen-2-yl)methanone

The mol­ecule of the title compound, C34H24O4, possesses crystallographically imposed twofold C 2 symmetry. The two 2-naphthoyl groups at the 1- and 8-positions of the central naphthalene ring are aligned almost anti­parallel [5.21 (5)°]. The dihedral angle between the central 2,7-dimeth­oxy­naphthalene unit and the terminal naphthyl groups is 75.13 (4)°. In the crystal, weak C—H⋯O hydrogen bonds and π–π stacking inter­actions [centroid–centroid and inter­planar distances are 3.6486 (8) and 3.3734 (5) Å, respectively] are observed

7-Meth­oxy-1-(4-nitro­benzo­yl)naph­thalen-2-yl 4-nitro­benzoate

In the title compound, C25H16N2O8, the dihedral angle between the naphthalene ring system and the benzene ring of the nitro­phenyl ketone unit is 82.64 (7)°. The bridging ester O—C(=O)—C plane makes dihedral angles of 42.12 (8) and 11.47 (9)°, respectively, with the naphthalene ring system and the benzene ring of the nitro­phenyl ester unit. In the crystal, two types of weak inter­molecular C—H⋯O inter­actions are observed

2,7-Dimeth­oxy-1,8-bis­(4-phen­oxy­benzo­yl)naphthalene

In the title mol­ecule {systematic name: [2,7-dimethoxy-8-(4-phenoxybenzoyl)naphthalen-1-yl](4-phenoxyphenyl)methan­one}, C38H28O6, the 4-phen­oxy­benzoyl units adopt a syn orientation with respect to the naphthalene ring system. The inter­nal benzene rings, A and B, make dihedral angles of 86.72 (5) and 79.22 (5)° with the naphthalene ring system. The two terminal benzene rings, C and D, of the 4-phen­oxy­benzoyl groups are twisted with respect to benzene rings A and B, with dihedral angles of A/C = 62.72 (8) and B/D = 87.61 (6)°. In the crystal, H atoms in the naphthalene system make two types of inter­molecular C—H⋯O inter­actions with the carbonyl O atom and the phenyl etheral O atom of neighbouring mol­ecules. Mol­ecules are further linked by C—H⋯π inter­actions involving a H atom of terminal benzene ring D and the π-system of the inter­nal benzene ring A, forming dimers centered about an inversion center

{8-[4-(Bromo­meth­yl)benzo­yl]-2,7-dimeth­oxy­naphthalen-1-yl}[4-(bromo­meth­yl)phen­yl]methanone

In the title compound, C28H22Br2O4, the two 4-bromo­methyl­benzoyl groups at the 1- and 8-positions of the naphthalene ring system are aligned almost anti­parallel, the benzene rings forming a dihedral angle of 2.94 (16)°. The dihedral angles between the benzene rings and the naphthalene ring systems are 70.98 (13) and 72.89 (13)°. In the crystal, centrosymmetric­ally-related mol­ecules are linked into dimeric units by inter­molecular C—H⋯O inter­actions

Methyl 4-(2,7-dimeth­oxy-1-naphtho­yl)benzoate

In the title compound, C21H18O5, the dihedral angle between the naphthalene ring system and the benzene ring is 86.65 (6)°. The bridging carbonyl C—C(=O)—C plane makes dihedral angles of 83.57 (7) and 20.21 (8)°, respectively, with the naphthalene ring system and the benzene ring. The ester O—C=O plane and the benzene ring are almost coplanar, making a dihedral angle of 3.81 (18)°. The two meth­oxy groups lie essentially in the naphthalene ring plane [C—O—C—C torsion angles = 2.1 (2) and −1.44 (19)°]. In the crystal structure, a centrosymmetric dimer is formed through C—H⋯O bonds connecting the 7-meth­oxy group and the carbonyl O atom of the ester group. The dimers are further linked by C—H⋯O hydrogen bonds between the methoxy­carbonyl group and the bridging carbonyl O atom

(2,7-Dimeth­oxy­naphthalen-1-yl)(phen­yl)methanone

The asymmetric unit of the title compound, C19H16O3, contains three independent conformers. Each of the three conformers has essentially the same feature of non-coplanar aromatic rings whereby the aroyl group at the 1-position of the naphthalene ring is twisted in a perpendicular manner to the naphthalene ring. The dihedral angles between the benzene ring planes and the naphthalene ring systems are 75.34 (7), 86.47 (7) and 76.55 (6)° in the three conformers. The crystal structure is stabilized by inter­molecular C—H⋯O hydrogen bonds

2-(2,7-Dimeth­oxy-1-naphtho­yl)benzoic acid

In the title compound, C20H16O5, the dihedral angle between the naphthalene ring system and the benzene ring is 67.43 (5)°. The bridging carbonyl C—C(=O)—C plane makes dihedral angles of 82.64 (6) and 41.79 (7)°, respectively, with the naphthalene ring system and the benzene ring. The dihedral angle between the carb­oxy O—C(=O)—C plane and the benzene ring is 36.38 (7)° and that between the bridging carbonyl C—C(=O)—C plane and the carb­oxy O—C(=O)—C plane is 51.88 (8)°. The crystal structure is stabilized by inter­molecular O—H⋯O and C—H⋯O hydrogen-bonding inter­actions. An intra­molecular C—H⋯O hydrogen bond occurs between a naphthalene H atom and the carbonyl O atom of the carb­oxy group

Effect of Cooling Rate on the Mechanical Strength of Carbon Fiber-Reinforced Thermoplastic Sheets in Press Forming

The purpose of this study is to elucidate the effect of the cooling rate of the carbon fiber-reinforced thermoplastic (CFRTP) sheets on the mechanical property in the press forming within 1 min cycle time. In order to pay attention only to the compression stage after the deformation stage in press forming, a flat sheet of dimensions 200 mm × 100 mm × 3 mm was produced. It was fabricated by stacking 15 CFRTP sheets of 0.2-mm-thick plain woven fabric impregnated with PA6, preheating them to 280 °C and pressing them at 5 MPa using a die cooled from near the melting temperature of PA6 with various cooling rates. Cooling rate of −26 °C/s with pressure holding time (defined in this study as the period that the pressure sensor detects high pressure) of 7 s and that of −4.4 °C/s with pressure holding time of 18 s gave a flexural strength of 536 and 733 MPa, respectively. It was found that the cooling rate during pressure holding is related to the mechanical property of press-formed CFRTP part. © 2017 ASM InternationalEmbargo Period 12 month

Effect of press slide speed and stroke on cup forming using a plain-woven carbon fiber thermoplastic composite sheet

Carbon-fiber-reinforced thermoplastic (CFRTP) is viewed as a prospective material for high-cycle production of CFRP parts. This paper deals with a process whereby a preheated thermoplastic plain-woven carbon fiber fabric sheet is formed into a circular cup by a mechanical servo-press. The effects of press parameters, specifically the bottom dead center and slide speed in the forming of CFRTP cup, on the press load, pressure, internal temperature, shape accuracy, and internal structure have been investigated. A plain-woven carbon-fiber-reinforced PA6 thermoplastic sheet was used. The sheet consisted of four layers of woven 3K carbon and had a thickness of 1 mm. The sheet was heated to 320°C under a halogen heater so that it would be around the recommended temperature for forming 260°C after transfer to the mold. The sheet was pressed into a circular cup shape by a cold mold while the periphery was cramped by a heated holder so as not to cool the sheet before it was pulled into the mold cave. Die clearance was designed considering the thickness increase due to the fiber concentration during the forming. By increasing the slide stroke to the bottom dead center, the applied press load was increased and the internal structure was improved, showing no voids. By increasing the slide speed, the final press load was reduced and shape accuracy was improved through a good pressure distribution on the mold. Measurement of the surface temperature of the sheet during the forming revealed that it remained in the melting region of the resin in the case of fast slide speed, but dropped below the melting temperature in the case of low slide speed. This difference apparently led to spring-in or spring-back after the forming. The experimental results indicate that appropriate balance among press speed, bottom dead center, and sheet temperature is important in the high-cycle forming of CFRTP. © 2016, Fuji Technology Press. All rights reserved