Poly Vinyl Chloride Compounds Research Articles

Binary amide-containing tung-oil-based Ca/Zn stabilizers: effects on thermal stability and plasticization performance of poly(vinyl chloride) and mechanism of thermal stabilization

N-(2-amino ethyl) tung maleamic acid (AETMA) and N-(2-amino phenyl) tung maleamic acid (APTMA) were prepared from the ammonolysis of ethidene diamine (ED) and p-phenylenediamine (PPD) respectively with tung-maleic anhydride (TMA). Then LAETMA-Ca, LAPTMA-Ca, LABTMA-Zn and LAPTMA-Zn were separately synthesized through a one-step method and characterized by Fourier transform infrared spectrometry (FTIR), 1H nuclear magnetic resonance (NMR) and inductively coupled plasma atomic emission spectroscopy (ICP-AES). LAETMA-Ca/LAETMA-Zn and LAPTMA-Ca/LAPTMA-Zn were both used as thermal stabilizers of polyvinyl chloride (PVC) and investigated using Congo red test, thermal aging test, ultraviolet-visible spectrometry, thermogravimetric analysis (TGA), TGA-FTIR, and TGA–mass spectrometry (MS). Their stabilizing efficiencies were compared with other common stabilizers. Dynamic mechanical of the PVC compounds were also studied. The LAPTMA-Ca/LAPTMA-Zn exhibits excellent long-term stability and better plasticization performance for PVC than other stabilizers, and thus can partly replace di(2-ethylhexyl) terephthalate in the processing of PVC. The mechanism underlying the stabilizing action of LAPTMA-Ca/LAPTMA-Zn is suggested.

Graphene oxide as a compatibilizer for polyvinyl chloride/rice straw composites

Abstract In this study, polyvinyl chloride (PVC)/rice straw (RS)/graphene oxide (GO) sustainable nanocomposite was prepared using the direct compounding method. Structural, morphological and mechanical properties of fabricated sustainable nanocomposites were compared with unfilled and RS-filled PVC compounds. Mechanical characteristics of PVC decreased with loading RS fibers. The main reason for the mechanical failure of PVC/RS composite is the incompatibility between PVC and RS fibers. GO nanosheets are used here to improve the compatibility between RS fibers and PVC macromolecules. Compared to the neat PVC, maximum strength of the RS/GO-loaded PVC composite increased up to 31%, with incorporating only 1 wt% of GO nanosheets. This enhancement in the mechanical characteristics of PVC/RS/GO nanocomposite can only be due to the role of GO nanosheets as a compatibilizer, as 1 wt% GO loading can only increase the mechanical strength of PVC compounds up to 9%. Fourier transform infrared spectroscopy results are used here to study the nature of these behaviors. It is suggested that the non-covalent and physical interactions between cellulose/hemicellulose portions of RS fibers and GO functional groups result in the enhancement of mechanical characteristics. Consequently, GO can be considered as a new compatibilizer for fabricating high performance PVC-based sustainable nanocomposites.

Thermal, mechanical, and acoustic properties of silica‐aerogel/UPVC composites

ABSTRACTThe properties of silica‐aerogel/UPVC composites have been investigated with emphasis on sound and heat insulation. UPVC is a material of construction for window profiles and drainage pipes. Hydrophobic silica aerogels were synthesized using silicate sodium as a precursor through a two‐step sol–gel process. The physical and textural properties of the synthesized silica aerogels such as density, surface area, and particle size were analyzed using SEM and BET analysis. Then, the synthesized aerogels were mixed with Unplastisized Polyvinyl Chloride (UPVC) compound at five different weight ratios in an internal mixer to find out the effects of silica aerogels on the thermal, mechanical, and acoustical characteristics. The prepared UPVC/aerogel composites were characterized for tensile properties, impact strength, hardness, Vicat softening temperature, thermal conductivity, sound absorption, and sound transmission loss. The results revealed that adding silica aerogel in to the matrix of UPVC increases its hardness and softening temperature while decreases impact strength. The thermal conductivity of UPVC was decreased by up to 50% using silica aerogel. The sound absorption property of UPVC was increased up to three times by using silica aerogels due to its high porosity. Silica aerogel increased the maximum sound transmission loss of UPVC in the low frequency range. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44685.

A study of stearyl alcohol bloom on Dan Hill PVC dolls and the influence of temperature

A study was conducted to investigate white bloom found on more than 130 polyvinyl chloride (PVC) dolls from the 1980s and 1990s produced by the Danish factory Dan Hill Plast A/S. The bloom was discovered on the dolls after 10 years of storage in a climate controlled facility with average temperature at 11–12°C and a relative humidity at 50 ± 5%. Analysis of the dolls and the bloom was carried out using Fourier transform infrared spectroscopy, which revealed that the bloom consisted primarily of stearyl alcohol. Subsequent analysis with gas chromatography–mass spectrometry showed a minor presence of cetyl alcohol. It is proposed that the alcohol had been added as a lubricant to aid flow during processing. The stearyl alcohol was almost completely reabsorbed into the PVC dolls following one month storage at room temperature, suggesting that low temperature storage played a decisive role in the appearance of the bloom. It is likely that a decrease in temperature has led to a decrease in compatibility of the stearyl alcohol in the PVC compound, thus promoting its exudation. This paper also discusses an extreme bloom of white crystals on other PVC dolls of unknown provenance.

The Effect of Triacetin on the Plasticization Efficiency and Tensile Properties of Polyvinyl Chloride/di-2-Ethyl Hexyl Phthalate/Triacetin Compounds

The use of triacetin as an alternative plasticizer to polyvinyl chloride (PVC) was studied in term of plasticizer efficiency and tensile properties before and after ageing. The efficiency of plasticizers was evaluated based on the glass transition temperature (Tg) and the hardness value of the compounds. The Tg and hardness of all PVC/DEHP/Triacetin compounds are lower than PVC/50DEHP and PVC/50Triacetin compounds indicating synergistic plasticisation effect between both DEHP and Triacetin within the PVC compounds. The low molecular weight and chemical structure of triacetin are believed to contribute to the highest tensile strength, elongation at break and modulus of the PVC/triacetin compared with PVC/DEHP and PVC/DEHP/triacetin compounds. However, the migration ability of the triacetin plasticizer is believed to result in the biggest changes of the tensile properties of PVC compounds plasticized with triacetin before and after ageing.

DIPHENOXYETHYLPHTALATES AND BUTOXYETHYLPHENOXYETHYLPHTALATES NEW PVC PLASTICIZER

To date, polyvinylchloride (PVC) is one of the most widely used large-scale polymers produced both in Russia and abroad. But the number of different types of products manufactured on its basis, undoubtedly, occupies a leading position. The most extensive application of PVC materials is construction. However, throughout the life of building materials and products made of polyvinylchloride (PVC) are exposed to aggressive environments of different origin (atmosphere, soil, acid, alkali, salts and their solutions, mineral and organic substances and etc.). Thus there is a significant change in their mechanical properties. Therefore, further development of PVC production and the constant expansion of the range of its application, primarily determined by the development of new chemical additives - plasticizers that meet the demands of modern exploitation. In this regard, relevant and practically significant is the question of creation of competitive formulations of PVC compounds for construction purposes that meet modern technological and operational requirements and with specific properties. This paper presents the obtaining methods and physico-chemical and mechanical properties of new plasticizers – diphenoxyethylphtalates and butoxyethylphenoxyethylphtalates based on ethoxylated alcohols (phenol and butanol) used for obtaining special materials for construction application. The optimal conditions of obtaining them through a two-stage esterification of phthalic anhydride in a single reaction volume ethoxylated alcohols. It was found that PVC formulations adding developed plasticizers by all indicators meet the requirements of the applicable standards and by such indicators as stress at elongation, breaking stress, petrol, oil and heat resistance, even superior to standard samples. Developed phthalates on the basis of ethoxylated alcohols were promising plasticizers of polyvinylchloride.

Mechanical Properties and Dimensional Stability of Rigid PVC Foam Composites Filled with High Aspect Ratio Phlogopite Mica

High aspect ratio Phlogopite mica was used to enhance the dimensional stability and mechanical properties of extruded rigid Polyvinyl Chloride (PVC) foam. Mica was added to rigid PVC compound at different concentrations (0 - 20 wt%) and processed using a single screw profile extruder. PVC foam-Mica composites were characterized for their dimensional stability, and structural, thermal, and mechanical properties. Experimental results showed that the dimensional stability increased by 44% and heat resistance of the samples improved as the amount of mica increased in the composites. The storage modulus and tensile strength of the composites were also enhanced with the addition of mica. However, increasing the concentration of mica had no significant effect on the impact and flexural properties of the composites. SEM micrographs show good dispersion and orientation of the mica flakes along the cell walls of the PVC foam. Overall, the platy structure and physical properties of mica seemed to have played an important role in providing good interfacial bonding with the cell membranes of the foam, thus enhancing the dimensional stability of the PVC- Mica foam composites.

PVC modification with biobased poly(hydroxyalkanoates)

Supported by numerous calculated and empirical data, a miscibility between polyvinylchloride (PVC) and biobased poly(hydroxyalkanoates) (PHAs), PHAs along with its utilization in plasticization, toughening, and processing improvement is discussed in unplasticized and plasticized (semirigid to flexible) PVC compounds. The long-term thermal stability of PVC stabilized with BaZn salts is shown to be improved in the presence of PHAs and the short-term stability (initial color hold) slightly reduced. The biobased PHAs are also shown to improve UV stability of PVC by offsetting the yellowing of PVC and not causing additional photodegradation. The transparence and durability of PVC are found to be unaffected by the presence of minor phase of otherwise biodegradable PHA. The discussed PHAs offer a new, ecologically attractive, and simplified approach to PVC formulation in which multiple processing and modifying additives could be replaced with a single product, eliminating both undesirable additive interactions and the need to stabilize unstable ingredients. J. VINYL ADDIT. TECHNOL., 21:259–271, 2015. © 2014 Society of Plastics Engineers

Evaluation performance of multiple plasticizer systems on the physicomechanical, crystallinity and thermogravimetry of polyvinyl chloride

Abstract The flexibility of polyvinyl chloride (PVC) materials is crucial in the production of urine bags and urinary tubing. However, the combination and concentration of plasticizers offers a variation of the plasticizing efficiency to the PVC matrix. In this study, several types of plasticizers, namely dioctyl adipate (DOA), diisononyl phthalate (DINP), dioctyl terephthalate (DOTP) and epoxidized soybean oil (ESO) were added into the PVC matrix to enhance the flexibility of PVC compounds. Increasing the plasticizer loading level improved elongation at break of PVC compounds, whereas the tensile strength, hardness and specific gravity deteriorated. In addition, DOA added to PVC compounds exhibited the highest plasticizing effect with the highest elongation at break results at lower percentages of plasticizer (≤50%). This is due to the linear chain of the DOA plasticizer promoting the slippage effect of polymer chains during stretching and thus imparting a higher flexibility. In addition, a higher loading level of plasticizer in PVC compounds also produced a marginal increment on the crystallinity and thermal stability of PVC compounds. Overall, DINP/DOA added to PVC compounds exhibited the highest flexibility effect (elongation at break) at higher percentages, but lowered tensile strength and crystallinity.

Emerald Kalama Chemical extends its K-Flex family of phthalate-free plasticizers

In the USA, Emerald Kalama Chemical, a business unit of Emerald Performance Materials, has expanded its family of non-phthalate plasticizers with the introduction of two new products: Kalama™ K-Flex® PG and Kalama K-Flex 850P. The K-Flex PG product has been specifically formulated to optimize the performance of polyvinyl chloride (PVC) compounds, while K-Flex 850P is designed to enhance the characteristics of vinyl and plastisol systems, the company says.

Photodegradation profiles of PVC compound and wood/PVC composites under UV weathering

This work aimed to study the effect of different ultraviolet (UV) weathering conditions (natural and accelerated) on the photodegradation of polyvinyl chloride (PVC) and wood/polyvinyl chloride (WPVC) composites by considering the structural and physical changes of PVC and WPVC samples as well as examining the photodegradation profiles at different depths from the sample surfaces. The photodegradation of PVC and WPVC composites under natural weathering condi- tions were lower than those under accelerated weathering conditions. The addition of Tinuvin P stabilizer at 2 phr was suf- ficient to stabilize PVC and WPVC composites, whereas the presence of wood appeared to accelerate the photodegradation of PVC under both natural and accelerated weathering conditions. When considering the photodegradation profiles at dif- ferent depths of the samples, it was found that the polyene and carbonyl sequences of PVC and WPVC composites were high at the sample surfaces and tended to decrease rapidly with increasing depth from the specimen surface before stabiliz- ing at a depth of 60 µm for PVC and 80 µm for WPVC composites. The differences in specimen depths for the stabilization of polyene and carbonyl sequences in PVC and WPVC samples implied that the presence of wood particles enhanced the absorption of UV radiation by the WPVC composite samples.

Galata Chemicals extends Drapex Alpha family of bio-based plasticizers for PVC

Polymer additives specialist Galata Chemicals has introduced Drapex® Alpha 200C as the latest addition to its recently introduced [ADPO, June 2012] Alpha series of natural oil-based primary plasticizers. The new bio-based offering has been designed for use in white and clear polyvinyl chloride compounds as well as speciality applications with demanding performance requirements, the company says.

The Effect of Shear on the Properties of Rigid PVC

The rheological and fusion behavior of polyvinyl chloride (PVC) compounds plays a dominant role inthe processing operations and in the development of physical properties in the processed material. Acomprehensive study was made in this work to evaluate the effect of shear and thermal history on stability, mechanical and rheological properties of rigid PVC compounds. Different samples of Rigid Poly vinyl chloride including dry blend powder, granules, and bottles molded from both were examined. A study was also made on recycled RPVC where 25% of reclaimed material was continuously blended with fresh dry blend and processed for 15 cycles. Results showed that compaction of the PVC material took place in the brabender plastograph at constant temperature and shear stress. Correlations were given to explain results concerning residual stability and rheological behavior. Furthermore, it was seen that elongation and tensile impact are dependent on shear history.

Computer-aided design and optimization of profile extrusion dies for thermoplastics and rubber: a review

A review is provided of issues and techniques in design and optimization of profile extrusion dies for thermoplastics and rubber, with particular emphasis on unplasticized polyvinyl chloride and rubber compounds. Traditional profile die design methods are contrasted with computer-based ones, with respect to efficiency and economic benefits. The main types of die construction are outlined. Physical phenomena relevant to the design and performance of dies are summarized, including: rheology and kinematics of the flow, wall slip, extrusion instabilities, residence time and degradation, extrudate swell, draw-down, and thermal effects. Approaches and strategies for die design are explained, including: flow balancing – with guidance from analytic flow results, the Avoid-Cross-Flow strategy, use of flow separators, and designing for extrudate swell. Published computer simulations of die flow used to assist with design are reviewed. Introducing automatic die design, the structure and elements of a computerized design optimization environment are set out. Key components and options within this are described, including: objective functions, constraints, design variables, optimization algorithms, design parameterization and flow domain meshing, and optimization strategies. Published implementations of computerized profile die design optimization are described. Automatic design optimization is compared with the work of a designer assisted by flow simulations in the industrial environment, showing how substantial reductions in demands on the designer's time are possible. The nature and potential of robust design is outlined, with techniques for its implementation. Conclusions are drawn as to the present state of the art in computer-assisted profile die design and optimization, and potential advances.

Effect of 1,2-polybutadienes on properties of plasticized polyvinyl chloride

The effect of 1,2-polybutadienes of various molecular weights and structures on the rheological and physicomechanical properties and on the heat resistance of plasticized polyvinyl chloride was studied. The possibility of using 1,2-polybutadienes as modifying components of polyvinyl chloride compounds, improving their processability and enhancing their heat resistance, was examined.

INVESTIGATION OF THE SORPTIVE PROPERTIES OF PIGMENTED POLYVINYL CHLORIDE

The non-Fickian diffusion of water vapor through polyvinyl chloride (PVC) pigmented with kaolin was investigated. It is shown on the basis of the model proposed that the concentrational and time dependences of the effective diffusion coefficient of the PVC compound represent superpositions of the corresponding dependences of its structural components.

Wood-Polyvinyl Chloride Composite for Insulation of Electrical Wires: Fabrication and Investigation of Properties

In this study, five series of wood—polyvinyl chloride composite samples were prepared by granules production followed by extrusion process for insulation of cuprous wires. The effects of wood flour content and its size on thermal stability, physical, mechanical, and electrical properties of these composites were investigated. The obtained results show that the density as well as the mechanical properties decreases, as the wood flour content increases. Also, wood flour composites with smaller particles have better mechanical properties and lower density. Thermal decomposition of these composites was investigated by thermogravimetric analysis (TGA). In general, thermal decomposition of polyvinyl chloride is inhibited by the addition of wood flour to the polyvinyl chloride compound. Moreover, electrical tests showed high amounts of wood flour can’t be used when high volume resistivity is necessary.

Study on emission of decomposed chemicals of esters contained in PVC flooring and adhesive

2-Ethyl-1-hexanol (2E1H) is sometimes detected in indoor air at relatively high concentrations. The emission mechanism for 2E1H is considered to be that moisture with a high pH in concrete slabs and self-leveling sub-flooring material reacts with di-2-ethylhexyl phthalate (DEHP) in the polyvinyl chloride (PVC) flooring and compounds containing the 2-ethyl-1-hexyl group in the adhesive. 2E1H is considered to be one of the causes of odor in indoor air and sick building syndrome, so it is important to clarify the 2E1H emission mechanism for IAQ. However, there are few reports on any experimentation into 2E1H emission by chemical reaction involving building materials. In this study, PVC floorings are attached using various adhesives to a self-leveling sub-flooring material that contains water, and their 2E1H emission rates are measured. Furthermore, the components of the adhesives are determined using chemical analysis. It is found that 2E1H emission rates from the floor are affected by the type of adhesive used. On the other hand, some components in the adhesives may suppress the hydrolysis of esters. The hydrolysis of polymers and residual monomers in the adhesive causes 2E1H emission from the adhesive.

Reanalysis of updated mortality among vinyl and polyvinyl chloride workers: Confirmation of historical evidence and new findings.

BackgroundThe production of vinyl chloride (VC) and polyvinyl chloride (PVC) involves the use of various chemicals, some known to be toxic and potentially or definitely carcinogenic. The related potential risk often has not been properly investigated. Updated cancer mortality among different subgroups of workers employed in a VC-PVC production plant located in Porto Marghera (Italy) was re-analyzed using an internal reference group of workers with low (or null) exposure to VC.MethodsMortality of 1658 male workers was analyzed by Poisson regression. Relative risks (RRs) and 95% confidence intervals (CIs) for blue collar workers and their specific subgroups of PVC baggers, PVC compound, autoclave and other blue collar workers were calculated using technicians and clerks as an internal reference group. The follow-up covered the period 1972–1999.ResultsSignificantly increased mortality rates were observed for all causes of death among the whole blue collar workforce (RR = 1.55; 95% CI = 1.03–2.35; 229 deaths), PVC baggers (1.72; 95% CI = 1.04–2.83; 49 deaths) and PVC compound workers (1.71; 95% CI = 1.09–2.67; 72 deaths). Liver cancer, including angiosarcoma, was increased among autoclave workers (9.57; 95% CI = 3.71–24.68; 7 deaths) and cardiovascular diseases among PVC baggers (2.25; 95% CI = 1.08–4.70; 12 deaths). Hemolymphopoietic system tumors, leukemias and lymphomas prevalently, were found only among exposed workers, with 4, 4 and 6 deaths observed among PVC baggers, PVC compound and other blue collar workers, respectively. An excess of lung cancer was found among PVC baggers.ConclusionThis cohort analysis, based on internal comparison, confirmed previously reported specific risk excesses for liver tumors and liver cirrhosis among autoclave workers and for lung cancer among PVC baggers, and revealed PVC compound workers as a possible new at risk group for all causes, all tumors and for liver and lung tumors. In conclusion, RRs for all causes of death and all tumors were increased among all blue collar workers.

Flame Retardancy of Thermoplastic Polyurethane and Polyvinyl Chloride by Organoclays

Thermooxidative stability and peak of heat release rates of thermoplastic polyurethane nanocomposites are improved by organoclays; but time to ignition of these composites is reduced. A cable with a thermoplastic polyurethane nanocomposite jacket does not pass a simple flame spread test by a Bunsen burner, indicating that the reduction of the peak of heat release rate does not prevent the flame spread. Polyvinyl chloride (PVC) with organoclays shows a fast HCl release by an accelerated chain-stripping reaction of the polymer catalyzed by the quaternary ammonium compound within the organoclays resulting in strong discolorations. Synthesis routes based on ethylene-vinyl acetate copolymer (EVA) or thermoplastic polyurethane (TPU) masterbatches of organoclays strongly diminish the darkening of the PVC compounds. Cone calorimeter experiments do not show remarkably improved flame retardancy properties of PVC filled with organoclays.