ISSN:0193-7197    

DOI:10.1002/vnl.730060102

出版商:Society of Plastics Engineers, Inc.    

年代:1984

数据来源: WILEY

摘要:

AbstractThe results of the extrusiometer measurements made on a great number of different rigid poly(vinyl chloride) (PVC) compositions are analyzed. The laboratory extruders used in the experiments can be considered to be isothermic. The output rate is proportional to the extrusion speed and almost independent of the composition. The other characteristics—torque, die and back pressure—significantly depend on the composition of the compounds. The back pressure proved to be proportional to the die pressure, and thus does not give additional information. Processability is well characterized by the dissipated energy which can be calculated from the difference of the total introduced mechanical energy and the energy required to transport the melt through the capillary. The dissipated energy is closely related to the fusion characteristics of the compou

ISSN:0193-7197    

DOI:10.1002/vnl.730060103

出版商:Society of Plastics Engineers, Inc.    

年代:1984

数据来源: WILEY

摘要:

AbstractVarious formulations of unplasticized PVC dry blends were investigated by extrusiometer and laboratory batch mixer (mixing chamber). Torque versus time curves of the mixing chamber experiments were characterized by three, essentially independent data: fusion time, equilibrium torque, and stability time, corresponding to the three distinct phases of the processing. Fair correlation was found between fusion characteristics of the compound and the energy required for its processing in the extrusiometer. The effect of composition on extrusiometric and mixing chamber data was investigated by multiple linear regression technique. The results allow prediction of the effect of recipe changes.

ISSN:0193-7197    

DOI:10.1002/vnl.730060105

出版商:Society of Plastics Engineers, Inc.    

年代:1984

数据来源: WILEY

摘要:

AbstractThe influence of thermodynamic interactions among the components of a polymer system on mechanical properties and their retention on aging has been investigated. The systems considered involve plasticized poly(vinyl chloride)(PVC), and CaCO3fillers. Inverse gas chromatography was used to measure interaction parameters, and to express these in terms of acid‐base concepts. Interaction data were obtained over a wide temperature range. It was shown that the volume of plasticizers retained by the PVC correlates with the measured interaction parameters. Similarly, the interaction parameters identify a CaCO3filler preferred for reinforcing rigid PVC, and a different CaCO3filler for use in given PVC‐plasticizer combinations. The mechanical properties of filled PVC (up to 40 phr CaCO3), and particularly the ultimate properties of the compounds, correlate with interaction concepts, as do property retention data after accelerated aging of the compounds at 100°C. It is concluded that component interaction parameters may provide useful guidelines to the formulation of compounds with superior properties and reduced property losses due to a

ISSN:0193-7197    

DOI:10.1002/vnl.730060106

出版商:Society of Plastics Engineers, Inc.    

年代:1984

数据来源: WILEY

摘要:

AbstractPolycaprolactone at moderate usage levels has been determined to provide desirable modifications of both rigid and plasticized poly(vinyl chloride). In rigid PVC it effected significant improvement in melt processing as well as good modulus, tensile strength, and kerosene resistance. Impact strength was not measurably altered, but heat‐distortion temperature was appreciably lowered. In flexible PVC, polycaprolactone contributed increased tensile strength and ultimate elongation, reduced volatility, and kerosene extraction. Lowering of modulus and flex temperatures were similar to conventional liquid polymeric plasticizers, but melt processability was not as good as lower‐molecular‐weight plastic

ISSN:0193-7197    

DOI:10.1002/vnl.730060107

出版商:Society of Plastics Engineers, Inc.    

年代:1984

数据来源: WILEY

摘要:

AbstractRigid poly(vinyl chloride) was reinforced with 10 to 40 phr of 1/4‐inch glass fiber. This improved flexural modulus up to 140 percent, flexural strength 40 percent, and heat‐deflection temperature 8°C; and reduced creep by 90–95 percent, and the coefficient of thermal expansion by 50 percent. Thus a typical Type I rigid vinyl with glass reinforcement had flexural modulus 1,164,000 psi, flexural strength 16,500 psi, notched Izod impact strength 5.1 fpi; creep only 12 percent of normal unreinforced material, coefficient of thermal expansion only 50 percent of normal unreinforced material, and heat‐deflection temperature 79°C. Such balance of properties elevates rigid vinyl from a commodity plastic up to an engineering thermoplastic, capable of much wider and more economical utilization in high‐performance a

ISSN:0193-7197    

DOI:10.1002/vnl.730060108

出版商:Society of Plastics Engineers, Inc.    

年代:1984

数据来源: WILEY

摘要:

AbstractAddition of plasticizers to poly(vinyl chloride) generally increases its flammability and frequently increases smoke production during its burning. Flame retardants added to plasticized PVC can reduce flammability, but increase smoke production. This study shows that proper choice of combined use of other polymers, phosphate plasticizers, fillers and other flame retardants, produces measured synergistic improvements in flame retardance and smoke suppression which could benefit applications such as PVC wire and cable insulation.

ISSN:0193-7197    

DOI:10.1002/vnl.730060109

出版商:Society of Plastics Engineers, Inc.    

年代:1984

数据来源: WILEY

摘要:

AbstractAs the data base for phthalates and other monomeric plasticizer classes is broadened, and our understanding of toxic mechanisms and potential risks improves, it is anticipated that industry and government agencies alike will demonstrate that these products can be safely used. Progress will depend heavily on advancements in predictive animal testing science, and extrapolation of animal data to meaningful risk assessment in humans.Future directions for testing initiatives are being determined, with a leadership role being played by CMA. Much exploratory work remains, but the focus will continue to narrow on areas critical to human risk assessment.

ISSN:0193-7197    

DOI:10.1002/vnl.730060110

出版商:Society of Plastics Engineers, Inc.    

年代:1984

数据来源: WILEY

摘要:

AbstractThe evolution of the morphology of the PVC grains during the mass polymerization of vinylchloride monomer (VCM) has been studied. After nucleation of primary particles, a rapid flocculation step occurs that leads to grains. Continued polymerization inside the grains results in a progressive reduction in the pore volumes. Continuing the reaction to completion, if appropriate by adding a further amount of monomer, causes densifying of the grains leading, in some cases, to vitreous grains, which therefore are related to the cleanliness of the reactors used. The changes in the size of the constituent compartment affect both the process of preparation and the processing of the final product: degassing rate of monomer, and plasticizing rate. Thus, control of the degrees of conversion, associated with perfect cleaning of the reactor, which is easy in the case of the new vertical reactors, constitutes the key factors in the reproducibility of the process and the quality of the PVC produced.

ISSN:0193-7197    

DOI:10.1002/vnl.730060111

出版商:Society of Plastics Engineers, Inc.    

年代:1984

数据来源: WILEY

ISSN:0193-7197    

DOI:10.1002/vnl.730060101

出版商:Society of Plastics Engineers, Inc.    

年代:1984

数据来源: WILEY