ISSN:0193-7197    

DOI:10.1002/vnl.730050402

出版商:Society of Plastics Engineers, Inc.    

年代:1983

数据来源: WILEY

摘要:

AbstractThe correction for polymer and mercury compressibility is essential to the use of mercury porosimetry for the evaluation of the porosity of poly(vinyl chloride) (PVC) suspension granules. The polymer compressibility, however, varies with the morphology type of the granules. The technique outlined in this paper allows the appropriate correction to be made without the need for the prior determination of the polymer compressibility. Bulk‐compressibility factors for the polymer samples are derived from the porosimetry data.Surface areas of PVC granules, as derived from porosimetry data using two fundamentally different techniques, are in error because of the presence of “ink‐bottle” shape

ISSN:0193-7197    

DOI:10.1002/vnl.730050403

出版商:Society of Plastics Engineers, Inc.    

年代:1983

数据来源: WILEY

摘要:

AbstractFive to 15 percent of ethylene/vinyl acetate copolymers was compounded into rigid polyvinyl chloride, with the copolymers dispersed as discrete micro‐domains, produced very efficient synergistic improvement of impact strength; as the vinyl acetate content of the copolymer increased from 28 to 60 percent, the synergistic peak moved to higher copolymer content and became higher and broader. Copolymer content correlated directly with melt flow and thermal stability, and inversely to modulus, strength, and heat‐deflection temperature. The vinyl acetate content of the copolymer correlated directly with elongation, impact strength, and thermal stability, but inversely to modulus, heat‐deflection temperature, low‐temperature flexibility, and melt flow. When the copolymer content reached 25 percent, it formed a second continuous‐phase, interpenetrating the polymer network structure and acting as a polymeric plasticizer, producing thermoplastic elast

ISSN:0193-7197    

DOI:10.1002/vnl.730050404

出版商:Society of Plastics Engineers, Inc.    

年代:1983

数据来源: WILEY

摘要:

AbstractA study conducted to determine the suitability of calcium carbonate (CaCO3) fillers in exterior PVC applications revealed that the surface‐treated precipitated CaCO3s of average particle sizes 0.5 micron and 0.07 micron, in fact, minimized the initial yellowing of PVC seen on weathering. It is hypothesized that these particle‐size CaCO3s, being optimum for light scattering, provide greater UV protection. Further, the high surface areas of these CaCO3s increase the capacity to neutralize the HCl responsible for yellowing of the PVC. The optimum filler level is 5 to 10 phr. At this loading level, long‐term impact strength is also ret

ISSN:0193-7197    

DOI:10.1002/vnl.730050405

出版商:Society of Plastics Engineers, Inc.    

年代:1983

数据来源: WILEY

摘要:

AbstractRigid poly (vinyl chloride), PVC, is finding increasing use in outdoor applications as a replacement for conventional materials such as wood, aluminum, steel, and other materials. Formulating PVC for outdoor applications requires special attention to several essential properties in order to achieve the high‐quality standards needed over a long period of time. One area that needs modification in a rigid PVC formulation for outdoor applications is toughness. Impact modifiers used to improve the toughness of PVC in outdoor use are CPE, EVA copolymers, and acrylates.The all‐acrylic weatherable impact modifier is designed especially to modify PVC for outdoor use and ease of processability. We will review its key performance features with special emphasis on the processing advantages of the all‐acrylic impact modifier. The study of the influence of processing conditions on the physical performance of weatherable PVC compounds in a Ba/Cd stabilized window profile shows an acrylic modifier to give consistently high toughness over a wide temperature range and shearing fri

ISSN:0193-7197    

DOI:10.1002/vnl.730050406

出版商:Society of Plastics Engineers, Inc.    

年代:1983

数据来源: WILEY

摘要:

AbstractAlthough a number of qualitative and visual methods are used to judge dedusting effectiveness, there is no generally accepted test method in practice. A new method that quantitatively determines dedusting effectiveness, however, has been devised that allows a comparison of treated versus untreated samples using readily available equipment.

ISSN:0193-7197    

DOI:10.1002/vnl.730050407

出版商:Society of Plastics Engineers, Inc.    

年代:1983

数据来源: WILEY

摘要:

AbstractThe objective ofthis study was to determine whether or not chloroform (CHCl3) and carbon tetrachloride (CCl4) diffuse from poly(vinyl chloride) (PVC) or chlorinated poly(vinyl chloride) (CPVC) pipe into water in the absence of solvent cement. Milli Q water (water which has been deionized, demineralized, and purified of residual organic matter) and tap water were permitted to stand in specimens of recently extruded pipe for 14 days in an attempt to simulate a condition of prolonged stagnation. The CHCl3and CCl4in the water were then measured utilizing an analytical method sensitive to 0.01 μg/1 (ppb).CHCl3and CCl4do not diffuse from Geon PVC or TempRite CPVC pipe or fitting compounds in significant quantities under these test conditions. Where sporadic positive responses were noted, these were in the low or fractional μg/1 (ppb) ranges and are far lower than levels commonly found in chlorinated tap water. The low, sporadic values obtained for CHCl3and CCl4in both Milli Q and tap water do not permit the calculation of meaningful diffusion constant

ISSN:0193-7197    

DOI:10.1002/vnl.730050408

出版商:Society of Plastics Engineers, Inc.    

年代:1983

数据来源: WILEY

摘要:

AbstractA knowledge of the complete flow curve, or rheogram, of a PVC formulation depicting the variation of the melt viscosity over industrially relevant ranges of shear rate and temperature is essential in the design of polyer‐processing equipment, process optimization, and troubleshooting. These data are generated on sophisticated rheometers that are beyond the financial and technical means of most PVC processors. The only flow parameter that can be readily measured on an inexpensive apparatus is the melt flow index of the resin‐mix. In the present work, a method has been proposed to estimate the rheograms of a PVC formulation at temperatures relevant to its processing conditions with the use of a master curve, knowing the melt flow index and glass‐transition temperature of the formulation. A master curve that coalesces rheograms of different PVC formulations at various temperatures has been generated and proposed as a tool for estimating the flow

ISSN:0193-7197    

DOI:10.1002/vnl.730050409

出版商:Society of Plastics Engineers, Inc.    

年代:1983

数据来源: WILEY

ISSN:0193-7197    

DOI:10.1002/vnl.730050401

出版商:Society of Plastics Engineers, Inc.    

年代:1983

数据来源: WILEY