Showing papers on "Thermoplastic published in 2001"

Nanofiber-reinforced thermoplastic composites. I. Thermoanalytical and mechanical analyses

Abstract: This article is a portion of a comprehensive study on carbon nanofiber–reinforced thermoplastic composites. The thermal behavior and dynamic and tensile mechanical properties of polypropylene–carbon nanofibers composites are discussed. Carbon nanofibers are those produced by the vapor-grown carbon method and have an average diameter of 100 nm. These hollow-core nanofibers are an ideal precursor system to working with multiwall and single-wall nanotubes for composite development. Composites were prepared by conventional Banbury-type plastic-processing methods ideal for low-cost composite development. Nanofiber agglomerates were eliminated because of shear working conditions, resulting in isotropic compression-molded composites. Incorporation of carbon nanofibers raised the working temperature range of the thermoplastic by 100°C. The nanofiber additions led to an increase in the rate of polymer crystallization with no change in the nucleation mechanism, as analyzed by the Avrami method. Although the tensile strength of the composite was unaltered with increasing nanofiber composition, the dynamic modulus increased by 350%. The thermal behavior of the composites was not significantly altered by the functionalization of the nanofibers since chemical alteration is associated with the defect structure of the chemical vapor deposition (CVD) layer on the nanofibers. Composite strength was limited by the enhanced crystallization of the polymer brought on by nanofiber interaction as additional nucleation sites. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 79: 125–133, 2001

Advances in fusion bonding techniques for joining thermoplastic matrix composites: a review

Abstract: Joining composite materials is an issue because traditional joining technologies are not directly transferable to composite structures. Fusion bonding and the use of thermoplastic films as hot melt adhesives offer an alternative to mechanical fastening and thermosetting adhesive bonding. Fusion bonding technology which originated from the thermoplastic polymer industry has gain a new interest with the introduction of thermoplastic matrix composites (TPC) which are currently regarded as candidates for primary structures. The improvement of thermoplastic polymer matrices, with the introduction of recent chemistries such as PEEK, PEI and PEKEKK. exhibiting increased mechanical performance, service temperature and solvent resistance (for the semi-crystalline systems) also supported the growth of interest for fusion bonding. This review looks at the state of the art of fusion bonding technology and focuses particularly on the three most promising fusion bonding techniques: ultrasonic welding, induction welding and resistance welding. Physical mechanisms involved in the fusion bonding process for modelling purposes are discussed including heat transfer, consolidation and crystallinity aspects. Finally, the application of fusion bonding to joining dissimilar materials, namely thermosetting composites (TSC)/TPC and metal/TPC joints, is reviewed.

Temperature-controlled induction heating of polymeric materials

Abstract: The present invention provides new polymer induction bonding technology. Induction heating technologies are utilized to weld, forge, bond or set polymer materials. The invention provides controlled-temperature induction heating of polymeric materials by mixing ferromagnetic particles in the polymer to be heated. Temperature control is obtained by selecting ferromagnetic particles with a specific Curie temperature. The ferromagnetic particles (13,83) will heat up in an induction field, through hysteresis losses, until they reach their Curie temperature. At that point, heat generation through hysteresis loss ceases. This invention is applicable to bonding thermoplastic materials, wherein only the area to be heated has ferromagnetic particles in it; bonding of thermoset composites (17), which have been processed with a layer of thermoplastic material (19) on one side; curing of thermoset adhesives or composite resins; or consolidating thermoplastic composites.

Thermoplastic resin composition

Abstract: PROBLEM TO BE SOLVED: To provide a non-polyvinyl chloride thermoplastic resin composition that has working characteristics, for example, flexibility, calender fabricability, high-frequency welding, comparable to flexible vinyl chloride resin composition. SOLUTION: The objective thermoplastic resin composition comprises a resin mainly containing ethylene-vinyl acetate copolymer and a phosphoric ester in an amount of 0.01-1 pts.wt., per 100 pts.wt. of the resin where the phosphoric ester is a mixed ester including at least monoester and diester. In a preferred embodiment, the ethylene-vinyl acetate copolymer includes vinyl acetate in an amount of 12-30 wt.% and has the melt flow rate(MFR) of 0.1-30 g/10 min.

Thermoplastic resin composition

Abstract: PROBLEM TO BE SOLVED: To obtain a polyimide resin exhibiting improved melt stability, having decomposition resistance under an ultimate processing treatment condition SOLUTION: This thermoplastic resin composition having excellent melt flow stability is characterized in that the composition comprises (a) a polyimide resin and (b) a phosphorus-containing stabilizer, (a) the polyimide resin contains a structural unit of formula (I) and (b) the phosphorus-containing stabilizer has 10-100 wt% of the initial weight remaining by a thermogravimetric analysis (nitrogen atmosphere, 20 [ degC/minute] rate of temperature increase, 25-300 degC measurement range) Consequently the composition exhibits extremely improved melt stability and thermal decomposition resistance

Highly-resilient thermoplastic elastomer compositions

Abstract: A thermoplastic composition of (a) an acid copolymer, (b) a salt of a high molecular weight, monomeric organic acid; (c) a thermoplastic polymer selected from copolyetheresters, elastomeric polyolefins, styrene diene block copolymers, elastomeric polyolefins thermoplastic polyurethanes and copolyetheramides; (d) cation source; and (d) optionally a filler. Also included is use of such compositions in components of one-, two- and three-piece golf balls or multi-layered golf balls made therefrom.

Thermoplastic elastomers having improved low temperature properties

Abstract: The present invention provides a thermoplastic vulcanizate prepared by a process comprising the steps of dynamically vulcanizing rubber within a blend that includes the rubber and a thermoplastic resin, where the rubber comprises an elastomeric copolymer of ethylene, at least one α-olefin, and optionally one or more diene monomers, where the elastomeric copolymer is characterized by having a crystallinity, as measured by differential scanning calorimetry, of less than 10 J/g, an ethylene content that is less than 90 mole percent based upon the entire copolymer, a weight average molecular weight that is greater than about 20,000 as measured by GPC with polystyrene standards, a molecular weight distribution that is less than 7, and an ethylene compositional distribution that is less than about 4 percent for the closest 90 percent of fractioned samples.

Process of making a three-dimensional object

Abstract: High-performance thermoplastic materials are used in building a three-dimensional model and its supports, by fused deposition modeling techniques. In a preferred embodiment, the thermoplastic resin comprising used as the modeling material is selected from the group consisting of a polycarbonate resin, a polyphenylsulfone resin, and a polycarbonate/acrylonitrile-butadiene-styrene resin. An amorphous thermoplastic resin which self-laminates, bonds weakly to the modeling material, has a heat deflection temperature similar to the heat deflection temperature of the modeling material, and has a tensile strength of between 5000 psi and 12,000 psi is used as a support material. In a preferred embodiment, the thermoplastic resin used as the support material is selected from the group consisting of a polyphenylene ether and polyolefin blend, a polyphenylsulfone and amorphous polyamide blend, and a polyphenylsulfone, polysulfone and amorphous polyamide blend.

Thermoplastic superabsorbent polymer blend compositions and their preparation

Abstract: An extrudable thermoplastic superabsorbent polymer blend composition is disclosed. The blend compositions are especially well suited for preparation of extruded or molded articles such as monolayer films, multilayer films, nonwoven webs, sheets, foams, profiles, multilayer laminates, fibers, tubes, rods or pipes which in turn are well suited for preparation of power and communication cables or disposable absorbent articles such as diapers, sanitary napkins, tampons, incontinence products, hospital gowns or bed pads.

Miscibility and shape memory property of poly(vinyl chloride)/thermoplastic polyurethane blends

Abstract: The miscibility and the shape memory effect of PVC blends with segmented thermoplastic polyurethanes (TPUs), synthesized from diol-terminated polycaprolactone (PCL), hexamethylene diisocyanate, 4,4′-dihydroxy biphenyl, were studied. PVC was miscible with PCL segment in TPU and the glass transition temperature of this miscible amorphous domain varied smoothly with composition. When PVC was blended with TPU by the weight ratio of 8/2, the hysterisis in repeated cyclic tensile test was reduced compared with PVC. However, in 6/4 blends, unrecoverable permanent deformation was increased compared with PVC. Dynamic mechanical properties were examined to explain these results.

Molded article from thermoplastic composite material and method for producing the same

Abstract: A method for producing a molded article from a thermoplastic composite material comprising extruding a thermoplastic composite material which contains a thermoplastic resin and a plant filler in a combination such that the content of the plant filler is 50 to 90 wt % based on the total weight of the thermoplastic resin and the plant filler, wherein the thermoplastic composite material is extruded by means of an extruding molding apparatus which has at least an extruder, a heating and forming mold, and a cooling mold, the heating and forming mold and the cooling mold being connected directly The method can provide a molded article from a thermoplastic composite material which is less susceptible to discoloration or fading even when subjected to outdoor exposure for a long period of time and excellent in durability, and also is excellent in physical properties and appearance such as woody feeling, and further can be produced with high productivity and at a low cost

Foam of thermoplastic urethane elastomer composition and process for producing the foam

Abstract: A process for producing a foam of a thermoplastic urethane elastomer composition, which comprises the step (gas dissolving step) of preparing a molten thermoplastic urethane elastomer composition (A) comprising a thermoplastic urethane elastomer (A-1) and other thermoplastic elastomer (A-2) at a (A-1)/(A-2) mass ratio of 20/80 to 99/1, adding 0.1 to 30 parts by mass of carbon dioxide (B) to 100 parts by mass of the composition (A), and then mixing the resulting system to form a molten thermoplastic urethane elastomer composition (C) comprising the composition (A) and carbon dioxide (B) in a state mixed with each other, and the step (cooling step) of lowering the temperature of the composition (C). This process can give foams excellent in softness, heat insulating properties and surface appearance and is free from air pollution or depletion of the ozonosphere.

Resistance welding of thermosetting composite/thermoplastic composite joints

Abstract: An investigation of the resistance welding between carbon fibre (CF)-reinforced polyetherimide (PEI) and CF-reinforced epoxy laminates is presented. A three-dimensional transient finite element model (FEM) featuring heat transfer, consolidation and thermal degradation was used for simulating the process. A hybrid interlayer made of a glass fibre (GF) fabric essentially impregnated with PEI on one side and with epoxy resin on the other side was produced to provide mechanical interlocking between the thermoplastic (TP) and the thermosetting (TS) systems. The ‘optimal’ resistance welding time based on the maximum lap shear strength (LSS) was determined for three power levels and correlated to the time required to achieve bonding predicted by the FEM. Consolidation quality and failure mechanisms were discussed in relation with processing parameters. Experimental and simulated processing windows were constructed and correlated to each other. However, thermal degradation as predicted by the model did not correlate to a reduction in performance of the joint.

Fiber-reinforced recycled thermoplastic composite and method

Abstract: Fiber-reinforced recycled thermoplastic composites and methods for their manufacture are presented. In a preferred embodiment, the thermoplastic composite incorporates a matrix of recycled thermoplastic and a plurality of high modulus fibers, with the recycled thermoplastic including polyethylene, polypropylene, nylon, PET and styrene-butadiene rubber, and the high modulus fibers including glass fibers, natural fibers, carbon fibers, and aramid fibers. Preferably, each of the high modulus fibers have a minimum length of approximately ½ of an inch and a modulus of approximately one million psi.

Ink jet recorder

Abstract: PROBLEM TO BE SOLVED: To provide an ink-jet recorder capable of uniformly transparentizing an ink receiving layer in the width direction of the recording medium when a recording medium having an ink receiving layer containing thermoplastic resin particles in a surface layer is heated and pressed to transparentize the ink receiving layer. SOLUTION: The ink-jet recorder comprises a recording head 3 to perform recording by discharging an ink on a recording medium 1 having an ink receiving layer containing thermoplastic resin particles in the surface layer, a heating/pressing means 4 to heat and press the recording medium 1 to transparentize the ink receiving layer of the recording medium 1, a temperature control means to keep the temperature of the heat pressing means 4 within a predetermined temperature range, and a recording-medium transfer means to transfer the recording medium 1 recorded by the recording head 3 to the heating/pressing means 4. The heating/pressing means includes a plurality of heating elements 43 divided in the width direction of the recording medium 1. The temperature control means can control the heating elements 43 independently of one another. COPYRIGHT: (C)2009,JPO&INPIT

Impregnation of compressible fiber mats with a thermoplastic resin, Part I: Theory

Abstract: In many cases of composite processing by liquid matrix impregnation, the fiber reinforcement is compressed when it comes in contact with the liquid and then relaxes as the matrix flows within its pores. This phenomenon can be analyzed in terms of local fluid flow, mass conservation and mechanical equilibrium. A model is proposed to simulate the kinetics of impregnation, and the evolution of the fiber volume fraction profile as the resin front progresses, as well as after the front has reached the end of the mold. The analysis is then applied to the case of infiltration of needled glass fiber preforms by a polypropylene matrix, used in the production of Glass Mat Thermoplastic blanks.Aquantification of the effects of applied pressure and fluid viscosity on total process time is provided. It is shown that the time for preform relaxation after the fluid has filled the preform may be much larger than that for impregnation. As a result, an apparently well impregnated part may exhibit an inhomogeneous distribution of the reinforcement, in turn inducing a modification of the mechanical behavior and residual stress distribution

Modification of thermosetting resins and composites through preformed polymer particles: A review

Abstract: A review is presented that focuses on preformed particle modification of high performance thermosetting resins and composite systems. The modifiers reviewed consist of thermoplastic and rubber preformed particles with no size limitations. Both organic and inorganic preformed polymer particles are considered but not glass or hollow spheres. In this text, preformed particles are defined as those which do not require phase separation and remain in the shape in which they were added to the neat resin or composite. Therefore, these particles may be developed prior to the resin formulation and then added to the thermosetting resin or developed in situ (during resin formulation) before the resin is catalyzed or cured. This technical review of preformed particle modification of thermosetting resins and composite systems summarizes the utilization of these materials and their performance.

The effects of composition and processing variables on the properties of thermoplastic polyaniline blends and composites

Abstract: Pure polyaniline (PANI) has a high electrical conductivity and can be made soluble and thermoplastic, but it still lacks adequate mechanical properties for large-scale commercial use and therefore, it has been blended with other polymers such as poly(methyl methacrylate) (PMMA). In the work described in this paper, the scaled up synthesis of conductive polyaniline by an oxidative chemical method under controlled pH and temperature has been optimised. Re-doping of deprotonated insulating base with excess of the mono-functional organic acids such as p-toluenesulfonic (TSA) or dodecylbenzenesulfonic (DBSA) in aqueous media was successful. A wide range of techniques including TGA, GPC, EA, FTIR, XRD and SEM were employed for the characterisation of PANI powders and blends. Compositions of PANI-HCI, TSA or DBSA and thermoplastic matrix PMMA with or without a plasticiser were melt-processed by compression moulding for 3 min at 210°C to produce plaques. The effectiveness of four different phenolic plasticisers was compared and hydroquinone was found to produce the blends with the highest conductivities. A few preliminary injection-moulded plaques were made and their conductivities were compared with those of the compression-moulded samples.

Deformation of thermoplastic vulcanizates

Abstract: The stress–strain behavior of thermoplastic vulcanizate (TPV) materials is studied experimentally; a constitutive model for the behavior is proposed and found to successfully predict the important features of the observed stress–strain behavior. TPVs are a relatively new class of elastomer-like material consisting of a rather high-volume fraction of elastomeric particles (0.40

Thermoplastic film structures having improved barrier and mechanical properties

Abstract: The present invention relates to thermoplastic film structures having improved barrier and/or mechanical properties and methods for making the film structures. These improvements are achieved by incorporating into the thermoplastic film structures a polymeric nanocomposite comprising a polymer and nanosize particles of a modified clay.

Use of dendrimers as a processing aid and surface modifier for thermoplastic resins

Abstract: Dendrimer additives incorporated in thermoplastic resins (such as polycarbonate resins) are effective to alter the surface characteristics of the thermoplastic resin. Such compositions can be injection molded to produce articles in which the dendrimer additive is concentrated at the surface of the article to alter the properties of the resin. By selection of the type of dendrimer additive, the resulting characteristics of the molded article may be controlled.

Resistance Welding of Metal/Thermoplastic Composite Joints

Abstract: An investigation of the resistance welding between carbon fiber (CF) rein-forced polyetherimide (PEI) and aluminium substrates (7075-T6 grade alloy) is presented. A three-dimensional transient finite element model (FEM) featuring heat transfer, consolidation and thermal degradation was used for simulating the process. Two mechanisms are distinguished in the consolidation model: (1) removal of the initial surface profile of the laminate modelled by the establishment of intimate contact between the two substrate surfaces and (2) penetration of the thermoplastic (TP) polymer in the micro-pores of the aluminium oxide surface modelled using a capillary flow model. The “optimal” welding time based on the maximum lap shear strength (LSS) was determined for various power levels and correlated to the bonding time predicted by the FEM. Consolidation quality and failure mechanisms were discussed in relation to processing parameters. The effect of the welding operation on overaging (annealing) of the aluminium alloy ...

Lignocellulose fiber filler for thermoplastic composite compositions

Abstract: A discontinuous lignocellulose fiber is described for use as a reinforcing filler for thermoplastic composite compositions. The fiber filler includes a significant percentage by weight of long, “hair-like” fibers. Specifically, at least about 20 percent by weight of the fiber filler is discontinuous lignocellulose fiber with a fiber length greater than about 15 millimeters and a fiber diameter less than about 0.5 millimeters. A moldable thermoplastic composite composition including the discontinuous lignocellulose fiber comprises about 20 to about 50 percent by weight of the fiber filler and about 50 to about 80 percent by weight thermoplastic. The discontinuous lignocellulose fiber filler yields thermoplastic composite compositions having improved physical properties over basic thermoplastic. The improved physical properties can be achieved without the use of coupling agents, although coupling agents may be used to further enhance the composite properties. The discontinuous lignocellulose fiber is preferably derived from virgin, waste wood from either softwood or hardwood tree species depending on the end use of the composite composition. The thermoplastic can be selected from a number of post-consumer or post-industrial waste sources. Processes for the manufacture of the discontinuous lignocellulose fiber reinforcing filler and the thermoplastic composite compositions are also disclosed.