Thermoplastic Polybutylene Terephthalate Research Articles

Effect of Mixing Sequence of Polymer and Nanofillers on Thermo Mechanical as well as Morphological Property of the Nanocomposites

Blends of polybutylene terephthalate (PBT) and thermo tropic liquid crystalline polymer (LCP) and blend of PBT, LCP and nanosilica have been prepared by melt mixing technique. Polymer composites made by engineering thermoplastic PBT and reinforcing polymer LCP has been extruded in presence of nanosilica in different mixing sequence. Here the mixing sequence of PBT, LCP and nanosilica has been picked out so as to study the different changes that can be observed in the characteristics in each of the system. The resultant mixtures are then compression moulded in high temperature range. Microstructures of the blends have been studied by Field Emission Scanning Electron Microscope (FESEM). Thermal properties and dynamic behaviour of the composites have been analyzed by Thermo gravimetric Analysis (TGA) and Dynamic Mechanical Thermal Analyser (DMTA), respectively. From the TGA analysis it is evident that PNL has superior thermal stability than the other nanocomposites. FESEM analysis revealed that the nanosilica prefers the low viscous LCP phase than the high viscous PBT. PNL has the highest tensile modulus among all the nano composites due to migration of nanosilica from high viscous PBT to low viscous LCP phase. There is a remarkable enhancement in storage modulus value is observed in case of PNL system than the other nano composites.

An investigation into thermoplastic matrix 3D woven carbon fibre composites

Three-dimensional woven textile reinforced composites allow the optimisation and tailoring of specific material properties into the final component. The objective of this work is to investigate the processing characteristics of Cyclic Butylene Terephthalate (supplied by Cyclics Corporation) that polymerises to form a thermoplastic, Polybutylene terephthalate, and to impregnate a multi-layer carbon fibre three-dimensional woven angle interlock fabric to produce a three-dimensional woven thermoplastic composite. Through adjustments in process cycle, the significant processing parameters have been identified, which optimise the production of thermoplastic Polybutylene terephthalate composite parts. Three-dimensional multi-layer reinforcements were manufactured on a modified textile loom to produce fabrics with fibres orientated in the warp, weft and through-the-thickness directions. Thermal and mechanical tests were conducted on the thermoplastic composite and comparisons were made to an epoxy composite with the same weave architecture. It was discovered from thermal analysis and optical microscopy that a highly crystalline matrix was developed as a result of the standard fabrication process with microcracks formed throughout the matrix. Reprocessing and annealing of the 3DCFCBT laminate reduced the crystallinity of the polymer structure.

Industrial cure monitoring of CBT using DEA for wind energy

Dielectric Analysis (DEA) is a widely used method to measure the cure of many common thermosetting resins systems such as epoxies, polyesters, polyurethanes, polyimides, silicones, bismaleimides and phenolics. The objective of this work is to investigate the curing characteristics of a thermoplastic, Cyclic Butylene Terephthalate (CBT) (supplied by Cyclics Corporation) which polymerises to form Polybutylene Terephthalate (PBT). This paper reports on the results of ongoing experimental investigations in which DEA is used to relate the curing cycle to composite structural features and mechanical performance of a complex composite part. Through adjustments in curing parameters, the significant processing parameters have been identified which optimise the production cycle for thermoplastic PBT composite parts. The recorded ion viscosity is used to determine change in material viscosity, cure rate and cure time. These results have been analysed and presented as a processing guide for correct process control.

Monitoring the Degree of Conversion of Cyclic Butylene Terephthalate Using Dielectric Analysis

Dielectric analysis (DEA) is the most common technique used to determine the state of cure in-process for many thermosetting resins systems such as epoxies, polyesters, polyurethanes, polyimides, silicones, bismaleimides, and phenolics. The objective of this work is to investigate the processing characteristics of cyclic butylene terephthalate (CBT) (supplied by Cyclics Corporation) which polymerises to form a thermoplastic, polybutylene terephthalate (PBT). This paper reports on the interim results of ongoing experimental investigations in which DEA is used to correlate the process cycle to composite structural features and mechanical performance of a complex composite part. Through adjustments in process cycle, the significant processing parameters have been identified which optimise the production of thermoplastic PBT composite parts. The recorded ion viscosity is used to indicate change in material viscosity, conversion rate and process time. These results have been analysed and presented as a guide for correct process control.

BEST OF BOTH WORLDS

A TECHNOLOGY THAT GENERAL Electric passed on in 1999 has fallen into more appreciative hands. Though the incentives to bring cyclic butylene terephthalate (CBT) to market may have been too small for a high-volume resins maker like GE, CBT will suit Cyclics Corp. just fine as the foundation for a brand new chemical company. The cyclic form of butylene terephthalate comes in a mix of dimer, trimer, and tetramer forms made by breaking down polybutylene terephthalate (PBT). CBT is useful because of its low viscosity when melted. You go from a melt viscosity that is chewing-gum-like to a waterlike viscosity, says John Ciovacco, Cyclics' chief executive officer. After CBT is melted, catalysts are added to CBT to polymerize it during processing back into PBT, which is the ultimate form used in the molded part. This low-viscosity intermediate-step CBT creates an engineering thermoplastic—PBT—that can be used in processes designed for thermoset resins. For example, melted CBT ...

Phosphorus‐Containing polymers. I. Low temperature polycondensation of phenylphosphonic dichloride with bisphenols

AbstractThis paper describes the synthesis of aryl polyphosphonates from the reactions of phenylphosphonic dichloride [benzene phosphorus oxydichloride (BPOD)] with 4,4′‐thiodiphenol (TDP) and with 4,4′‐sulfonyldiphenol (SDP) employing a dry chlorinated hydrocarbon polymerization solvent, an amine acid acceptor and under low temperature conditions. The glass transition temperatures of the polymers from BPOD/TDP are 146°C and 83°C, respectively, and the polymers begin to lose weight at about 395°C in a nitrogen atmosphere. These polymers have good flame retardancy (FR), as indicated by high limiting oxygen indices (LOI) of 50–60. Thermoplastic polybutylene terephthalate containing 7% BPOD/SDP or BPOD/TDP polymer as an FR additive has LOI values of 29 and 30, respectively.