bluuebunny/crossref_metadata_2025_split huggingface dataset:
Applications of infrared spectroscopy to customer problems in the vinyl industry
Authors: Garcia Dana 
Published: April 2004

AbstractIdentifying polymers, additives and contaminants presents unique challenges. Fourier transform infrared spectroscopy (FT‐IR) coupled with spectral searching techniques is a very efficient and powerful methodology to answer most identification questions. It is based on the unique IR spectrum characteristic of each compound. This paper outlines procedures employed in the identification of typical PVC formulations, starting with the resin and proceeding to impact modifier, process aids, lubricants, stabilizer system and fillers. The emphasis is on FT‐IR microscopy as the most versatile approach requiring small samples and minimal to no sample preparation. Other commonly used FT‐IR techniques are also outlined. Wet separation protocols, applicability and limitations as related to FT‐IR analysis are discussed. Typical examples include vinyl siding, packaging and bottle formulations as well as contaminants often encountered in these formulations and raw materials.
Halogen‐free flame‐retardant plastics for electronic applications
Authors: Von Gentzkow W. , Huber J. , Kapitza H. , Rogler W. 
Published: April 2004

AbstractIn order to meet international standards, printed circuit board (PCB) base materials have to be flame‐retardant according to the UL 94V specification. Up to now this has been achieved with FR4 materials by using brominated aromatic components. FR4 materials are glass epoxy based and are by far most prevalent in PCB production. Unfortunately, in the case of fire or smoldering, these materials evolve highly corrosive, and, under unfavorable conditions, even highly toxic decomposition products. In the search for flame retardancy without the use of bromine, the effect of different structural elements on the burning behavior of cured resins has been investigated. As a result of these investigations an epoxy resin was developed that contains tailor‐made N‐ and P‐containing constituents that form flame‐retardant structures during processing and curing of the material. The new material meets all requirements for printed circuit boards and can be processed without any need to modify established technologies. Analytical and ecotoxicological investigations of the combustion products of the new material show that they are comparable with those of wood from the beech tree. PCBs and electronic assemblies manufactured therefrom successfully passed all functional tests. The base materials recently became commercially available.
Carboxylation of polypropylene by reactive extrusion with functionalized peroxides for use as a compatibilizer in polypropylene/polyamide‐6,6 blends
Authors: Manning Steven C. , Moore Robert B. 
Published: April 2004

AbstractVariable quantities of functionalized peroxides bearing carboxylic acid groups were reacted with polypropylene (PP) in a twin‐screw extruder. Systematic variations in the molecular structure of the peroxides were found to significantly affect the grafting efficiency of the carboxylic acid group onto the PP backbone, as well as affect the polymer degradation process. This behavior was attributed to the relative reactivities of the different free radicals generated by thermal decomposition of the peroxides. Furthermore, the functionalized polypropylene (f‐PP) was investigated as a compatibilizing additive for 80/20 PP/PA‐6,6 (polyamide 6,6) blends. With incorporation of the f‐PP into the blends, differential scanning calorimetry (DSC) showed an 80°C decrease in the PA‐6,6 crystallization temperature. A near linear increase in the impact strength of the blends was observed with f‐PP incorporations up to 30% of the PP phase. Moreover, blends containing 30% f‐PP demostrated impact properties approaching that of pure PA‐6,6.
The role of silicone powders in reducing the heat release rate and evolution of smoke in flame retardant thermoplastics
Authors: Pape Peter G. , Romenesko David J. 
Published: April 2004

AbstractNew powdered silicone additives for plastics have been developed that give benefits in flame retardant formulations. Cone calorimeter evaluations of thermoplastics, with or without other flame retardant additives, show reduction in rates of heat release, smoke generation, and carbon monoxide evolution. Other benefits that have been observed are: improved processing, reduced torque, reduced build‐up on screws, and increased impact strength. The effect of silicone powder additives on the combustion of several thermoplastics will be shown. A suggested mechanism is discussed.
A practical guide to the identification of monomeric plasticizers in flexible PVC compounds
Authors: Kozlowski Richard R. , Gallagher Thomas K. 
Published: April 2004

AbstractThe performance of a flexible PVC compound is often defined by its plasticizer content and composition. A simple, accurate and fast method of plasticizer identification can therefore be an effective quality control test and benchmark performance in new product development studies. Gas chromatography provides the most effective plasticizer identification method. Gas chromatography can be supplemented by infrared and liquid chromatography and physical observations to confirm identity.
Variations on the oxidative induction testing methodology for polymer analysis
Authors: Woo Lecon , Ling Michael T. K. , Westphal Stanley P. , Ding Samuel Y. 
Published: April 2004

AbstractWe have modified the ASTM method on oxidative induction testing (D‐3895‐92) into a generalized technique with considerably expanded applications to polymer systems in addition to the polyolefins. Testing parameters we have experimented with success are: much wider temperature ranges, oxygen pressure, combination of oven aging and the differential scanning calorimeter, and both the exothermic and endothermic degradation polymer systems. In terms of non‐olefin polymer systems, we have obtained good results from flexible PVC formulations, thermoplastic polyesters, styrene based thermoplastic elastomers, among others. Insights generated from these tests can be used to optimize polymer selection, formulation and processing conditions.
Ultraviolet light resistance of vinyl miniblinds
Authors: Grossman Richard F. , Krausnick Dale 
Published: April 2004

AbstractAccelerated ultraviolet light aging was carried out using lead stabilized commercial vinyl miniblinds as well as a vinyl composition designed for outdoor use. The levels of surface lead found after such exposure were compared with results obtained in the field by the North Carolina Department of Environment, Health, and Natural Resources (DEHNR).
Factors influencing the adsorption of stabilizers onto carbon black: Flow microcalorimetry studies
Authors: Peñta J. M. , Allen N. S. , Liauw C. M. , Edge M. , Valange B. 
Published: April 2004

AbstractThe surface activity of various kinds of carbon black toward phenolic antioxidants and hindered amine light stabilizers (HALS) was examined by using flow microcalorimetry (FMC). Phenolic hydroxyl and ester groups were found to be the moieties responsible for the adsorption activity of primary phenolic antioxidants onto the carbon black surfaces. Furthermore, a difference in the degree of phenolic hydroxyl hindrance by alkyl groups was found to be the main factor affecting the adsorption activity of the phenol group. A difference in the degree of substitution of the piperidine amine, as well as the number and type of functionality per molecule, are important factors that were found to influence the adsorption activity of HALS. Data from adsorption studies using model compounds, some of which represented functional portions of the stabilizer molecules, reflected behavior sin ilar to that observed with the stabilizers. In addition, these latter results showed that FMC analysis can yield potentially useful information beyond that given by the usual parameters such as BET surface area, I2, DBP, and CTAB adsorption values. Differences in the behavior between types of carbon black were evident and showed that the specific surface area is not the most important factor in the adsorption/desorption activity, but also the chemical nature of the surface. From the activity observed for model compounds, it was deduced that the presence of secondary and tertiary amine in the backbone and branch structures also has an important role in the adsorption activity of polymeric HALS. In general, the observed quantities can be related to the values of adsorption/desorption energy and to the molar mass of the probe.
Molecular weight distribution of commercial PVC
Authors: Pepperl G. 
Published: April 2004

AbstractThe molecular weight distribution (MWD) of commercial suspension grade poly(vinyl chloride) (PVC) resins with K values from 50 to 93 and mass grade PVC resins with K values from 58 to 68 has been determined by size exclusion chromatography (SEC), using literature Mark‐Houwink coefficients. The MWD is characterized by the number average molecular weight (Mn), the weight average molecular weight (Mw) and the polydispersity (Mw/Mn). Our results for Mw are consistent with recently published data, but we find different results for Mn and consequently for Mw/Mn. The polydispersity of PVC increases with increasing K value. This effect can be explained by two mechanisms. The first mechanism is a reduced terminating reaction rate between two growing polymer chains (disproportionation) at higher molecular weight owing to the reduced mobility of the polymer chains. The second mechanism is long‐chain branching of molecules with high molecular weight which lets the molecules grow at two ends. For two examples graphs of the measured MWD are compared with the theoretically expected MWD.
Guarding against bloom in FR/UV polypropylene fiber
Authors: Kuvshinnikova Olga I. , Lee Robert E. , Favstritsky Nick 
Published: April 2004

AbstractDisplacing polyamide and polyester fibers in the carpet industry with polypropylene (PP) has been hampered in a few key market segments. Markets that require resistance to flame and ultraviolet light have been the most difficult to penetrate owing to both technical and economical reasons. The migration of additives to the surface (blooming) has been one significant technical problem. This paper will review progress in the stabilization of flame‐retarded PP fiber and present new advances in this field.
Synthesis and antioxidative properties of novel multifunctional stabilizers
Authors: Habicher Wolf D. , Pawelke B. , Bauer I. , Yamaguchi K. , Kósa C. , Chmela Š. , Pospíšil J. 
Published: April 2004

AbstractNew multifunctional stabilizers containing hindered amino, phosphite, and in some cases also free phenolic moieties have been synthesized starting from tris(diethylamino)phosphine. Some of them proved to be efficient stabilizers for model hydrocarbons and for polypropylene during processing, thermo‐, and photooxidation. Various sterically hindered phenols, amines (HAS), and phosphites have been modified by the reaction with isophorone diisocyanate (IPDI) to get new multifunctional stabilizers for polymers. The synthesized products have been investigated regarding their thermal and antioxidative behavior. The novel urethane stabilizers are, depending during the polymer processing to release the antioxidatively active parent phenols.
Benefits of a high‐performance phosphite in the gamma irradiation of polyolefins
Authors: Stein Daryl , Stevenson Don 
Published: April 2004

AbstractThe highly active process stabilizer bis(2,4‐dicumylphenyl)pentaerythritol diphosphite (P1) was compared in a series of polyolefin formulations with tris(2,4‐di‐t‐butylphenyl) phosphite (P2). Because of its high activity, there was less polymer degradation during processing with P1 as compared to P2. As a result, improvements in color and other physical properties were observed for the polymers, not only during processing, but also after treatment with gamma radiation.
New class of antioxidants
Authors: Grossman Richard F. , Detweiler Mark B. 
Published: April 2004

AbstractAntibiotics containing phenolic ‐OH groups, such as amoxicillin and cefadroxil, have been found to be strong antioxidants in common plastics to a much greater extent than would be guessed from their structures. Vancomycin, which contains several such groups, is also a powerful antioxidant. It is possible that this characteristic plays a part in inhibiting bacterial expression of counteragents such as β‐lactamases.
Thermal degradation of PVC in the presence of polystyrene
Authors: Yao Qiang , Wilkie Charles A. 
Published: April 2004

AbstractThe thermal degradation of poly(vinyl chloride) (PVC) and blends of PVC with polystyrene has been studied using thermogravimetric analysis coupled to Fourier transform infrared spectroscopy. The degradation of PVC commences at weak links by an ionic pathway, but there is evidence to suggest the presence of a radical pathway at high temperatures. While there is some chemical interaction between PVC and polystyrene, the principal mode of stabilization is a physical process.
Vinyl chloride in rural water from pre‐1977 applications of PVC pipe
Authors: Carroll William F. , Eckstein Dave 
Published: April 2004

AbstractIn the early 1990s, vinyl chloride monomer (VCM) was found in a rural water system that included poly(vinyl chloride) (PVC) pipe manufactured prior to 1977. Because VCM, considered a human carcinogen, was not regulated in pipe until 1977, some pre‐1977 pipes could contain it at significant levels. Manufacturing processes adopted in 1975 and in place by 1977 reduced VCM levels by as much as a factor of 1000. Pipe manufactured by using the newer resin technology does not show detectable VCM migration under any reasonable installation circumstances. Migration of VCM is a function of pipe size, VCM concentration at time of installation, water temperature, and flow rate. History, scientific investigations, and conclusions drawn from field investigations are summarized. Tools for the determination of possible candidate systems, potential noncompliance, and remediation, both short‐term and long‐term, are provided. A spreadsheet‐based computer model of diffusion is described.
Enhanced weatherability of exterior PVC building products
Authors: Girois Stephane , Schipper Peggy S. 
Published: April 2004

AbstractPoly(Vinyl) Chloride (PVC) is used extensively as a material for the growing building‐products market. The color preferences of consumers for markets such as vinyl siding have forced the industry to seriously reconsider the use of PVC especially for the medium‐to‐dark color palettes, where the performance is critical. Organotin mercaptides have always been the stabilizers of choice in the U.S. market because of their inherent outstanding heat‐stabilization properties. On the other hand, this technology is also known to be a compromise between processability and weathering characteristics. In a market that drives for excellence, all additives must be optimized to meet the final performance requirement. Organotin carboxylates and specifically maleates have long been known for excellent weathering but have not been used extensively in the industry owing to less‐than‐optimum intrinsic heat stabilization efficiency, and in some cases, troublesome lachrymatory properties. A new generation of organotin maleates has been successfully developed to address both issues. This paper describes the improved lachrymatory behavior of the new technology compared to standard organotin maleates and also shows its outstanding weathering performance in PVC capstock compared with conventional organotin mercaptide during natural aging.
Sustainable development: How to weigh both economical and ecological cost? A new strategy for a combined optimization
Authors: Spindler Ernst‐Josef 
Published: April 2004

AbstractSustainable development attempts a combined optimization of ecological, economical and social development. One task, then, is to measure progress in these terms, i.e. to weigh, e.g. economical against ecological advantages. We have developed and tested a method that combines at least the most essential criteria of ecological and economical development, i.e. the ecological cost derived from ecobalance studies and the economical cost derived from life‐cycle cost calculations. The method consists of improving lower‐cost products as long as they are cheaper than their alternatives. These improved products, which cost the same or less, are then compared in an ecobalance study with the alternatives. In many cases these improved products show by far the best ecological results and cost no more than the alternatives. They thus have the highest optimization potential both from an economical and ecological point of view. A strategy that strives towards sustainable development optimizes rare economical and ecological resources in an ecoefficient way. One formulation of such a strategy: Use lower‐cost products and improve them by using all or part of the price difference relative to their alternatives; these optimized products are very often much better when comparing ecobalance results, and not more expensive than their alternatives. This is shown to be the case for PVC windows compared both to wood and aluminum windows. An alternate method, the monetarizing of ecological impacts, is briefly discussed.
New halogen‐free fire retardant for engineering plastic applications
Authors: Levchik Sergei V. , Bright Danielle A. , Alessio Gerald R. , Dashevsky Sophia 
Published: April 2004

AbstractA comparative study of the fire‐retardant efficiency of three commercial aryl phosphates—triphenyl phosphate (TPP), resorcinol bis(diphenyl phosphate) (RDP) and bisphenol A bis(diphenyl phosphate) (BDP)—in PC/ABS blends was carried out. The thermal and hydrolytic stability of the fire‐retardant resins, as well as their physical properties, was also studied. The use of RDP and BDP is preferred over TPP because of superior properties, whereas BDP shows better fire‐retardant efficiency, hydrolytic stability, and thermal stability than RDP.
Performance and antioxidant activity of phenol/phosphite antioxidants in synergistic blends in the thermal and photooxidation of high‐density polyethylene (HDPE) film: Influence of zinc stearate
Authors: Allen Norman S. , Enriquez Luis J. , Edge Michele , Liauw Christopher M. , Parrondo Aitor , Fontan Eusebio 
Published: April 2004

AbstractThe influence of zinc stearate (ZnSt) on the thermal and photochemical stabilities of phenolic antioxidant/phosphite combinations has been determined in HDPE by using FTIR analysis. The results show that while under thermal aging the effects are generally antagonistic, under photooxidation the effects are synergistic. The interactions appear to be dominated by the role of complex formation between the phosphites and ZnSt. Such interactions would remove the hydroperoxide effectiveness of the phosphite in thermal oxidation, while under light they could cause stabilization. Derivative UV and FTIR analysis on pre‐melt blends of the additives in solution shows evidence for strong complexation for the phosphite antioxidants. Other acid scavengers such as hydrotalcite and calcium stearate also appear to influence the behavior of phenolic antioxidants in thermal oxidation. The antagonistic effect of zinc stearate was also confirmed following a single pass in an extruder, where for all formulations there was a greater reduction in MFI associated with crosslinking.
New generation of long‐term stabilizers for polyolefins
Authors: Cangelosi Frank , Davis Leonard , Samuels Sari‐Beth 
Published: April 2004

AbstractPolyolefins are under evaluation for a variety of applications with increasingly stringent requirements, including long‐term exposure outdoors. While the range of physical properties and appearance has been extended by the development of new resins, additives are required to help maintain those properties upon exposure to sunlight, heat, and weather. The benefits of a new generation of light stabilizer with extraordinary efficiency in polyethylene (PE), polypropylene (PP), and other resins are discussed.
PVC wood: A new look in construction
Authors: Chetanachan W. , Sookkho D. , Sutthitavil W. , Chantasatrasamy N. , Sinsermsuksakul R. 
Published: April 2004

AbstractAs a result of the increasing environmental concern for forest protection, there is a rapidly growing demand for alternatives to wood products. PVC wood, which includes PVC foam and PVC/wood flour composite, shows improved performance over wood in the following properties: termite resistance, weathering aging, less moisture absorption, and ease of installation. It can be nailed, screwed, sawed, cut, and glued like wood by conventional tools without any special skills required. Although the bending strength of PVC wood is lower, it can be used for decorative applications, i.e., cornice, door, and siding.
Foaming of rigid PVC/wood‐flour composites through a continuous extrusion process
Authors: Mengeloglu Fatih , Matuana Laurent M. 
Published: April 2004

AbstractThe effects of chemical foaming agent (CFA) types (endothermic versus exothermic) and concentrations as well as the influence of all‐acrylic processing aid on the density and cell morphology of extrusion‐foamed neat rigid PVC and rigid PVC/wood‐flour composites were studied. Regardless of the CFA type, the density reduction of foamed rigid PVC/wood‐flour composites was not influenced by the CFA content. The cell size, however, was affected by the CFA type, independent of CFA content. Exothermic foaming agent produced foamed samples with smaller average cell sizes compared to those of endothermic counterparts. The experimental results indicate that the addition of an all‐acrylic processing aid in the formulation of rigid PVC/wood‐flour composite foams provides not only the ability to achieve density comparable to that achieved in the neat rigid PVC foams, but also the potential of producing rigid PVC/wood‐flour composite foams without using any chemical foaming agents.
PVC — origin, growth, and future
Authors: Braun Dietrich 
Published: April 2004

AbstractApplication of poly(vinyl chloride) (PVC) was first described in a patent in 1913, but only after 1930 did a sustained interest in PVC arise in a number of industrial laboratories. Nowadays PVC is the second thermoplastic resin behind polyolefins with a worldwide capacity of ca. 31 million tons. In its nearly 70 year history, PVC has contributed to much progress in polymer science and technology, e. g., to emulsion and suspension polymerization, detailed analysis of polymer structure, chemistry of stabilization, plasticization, chemical modification, and plastics processing. But PVC also plays an important role in many environmental discussions on polymers, e. g. chlorine chemistry, toxicity of vinyl chloride, or waste and recycling problems. Within the time frame of 70 years, some recent developments in controlled polymerization of vinyl chloride, stabilization, modification of bulk properties and chemical and material recycling of PVC are discussed.
Improving γ‐radiation stability of pvc—a review
Authors: Wang Qi , Nagy Sandor 
Published: April 2004

AbstractPVC has a significant tendency to degrade under γ irradiation. Therefore, considerable efforts have been made to improve its γ‐radiation stability. The purpose of this review is to summarize recent results in this area, with a special emphasis on the improvement of color stability of PVC‐based materials used in medical applications.