PVC Blends Research Articles

Suppression of dioxin emission in incineration of poly(vinyl chloride) (PVC) as hybridized with titanium dioxide (TiO2) nanoparticles

The present paper has demonstrated suppression of dioxin emission from poly(vinyl chloride) (PVC)/titanium dioxide (TiO2) nanohybrids. In our previous paper, we suggested a novel idea for the preparation of PVC/TiO2 nanohybrid through TiO2 nanoparticle-integrated hyperbranched poly(ɛ-caprolactone) (HPCL-TiO2), aiming at a breakthrough to solve the unresolved problem in the conventional PVC/TiO2 composites related to the poor dispersion of TiO2 nanoparticles in PVC polymer. The integration of TiO2 nanoparticles onto the HPCL could be successfully carried out by a dip-coating method based on the spontaneous self-assembly between TiO2 and HPCL. In this study, three kinds of hyperbranched poly(ɛ-caprolactone)s (HnPCLs) were prepared by varying the number, n, of monomeric units on the branched backbone chains. Thereby, it was possible to control the numbers of functional ends and the contents of TiO2 in the HnPCL-TiO2. The loadings of TiO2 in the HnPCL-TiO2s were found to be 4.37, 3.26, and 2.93wt% for n of 5, 10, and 20, respectively. The preparation of PVC/HnPCL-TiO2 (60/40) blends was performed through solution blending of HnPCL-TiO2 with PVC in tetrahydrofurane (THF) as solvent, and the dispersities of TiO2 in the resulting nanohybrids were investigated by field-emission scanning electron microscope (FE-SEM) equipped with energy dispersive spectroscopy (EDS). The FE-SEM/EDS results showed that TiO2 nanoparticles were dispersed well in PVC matrix, while some agglomerates of TiO2 was observed in the PVC+TiO2 sample prepared from the solution blending of PVC with the same amount of TiO2. The incineration experiments were performed by using a temperature-controllable electric furnace at 350°C under the flow of ambient air, and the exhaust gases resulting from the incineration process were collected. Prior to the identification of the components emitted in the incineration process, the GC experiments for calibration were performed on several commercial standards of dioxin and organic compounds known to be dioxin precursors. The GC results on the exhaust gases from the incineration of samples showed that the emissions of dioxin and precursors were largely suppressed with the increasing content of TiO2 in PVC/HnPCL-TiO2, i.e., the order of PVC/H5PCL-TiO2>PVC/H10PCL-TiO2>PVC/H20PCL-TiO2, as compared with those in the neat PVC/HnPCL without TiO2. Especially, the PVC/H5PCL-TiO2 with a maximum TiO2 loading of 1.6wt% showed removal efficiencies of ca. 60% up to 70% over the dioxin and dioxin precursors, which is equivalent to one and half to several times as much as the PVC+TiO2 samples prepared through the conventional route. The remarkable enhancement of the suppression of dioxin emission in the PVC/HnPCL-TiO2 might be attributed to the improvement of the degree of TiO2 dispersion in the nanohybrid.

Comparison of Physicomechanical Properties of NBR—PVC Blend Cured by Sulfur and Electron Beam

In this research, physicomechanical properties including tensile strength, elongation at break, hardness, resilience, and aging of acrylonitrile butadiene rubber—poly vinyl chloride (NBR—PVC) blend cured by sulfur and electron beam are investigated. The Taguchi method is employed in order to formulate the sulfur curing system. Electron beams in dose rates from 0 to 150 kGy are applied to cure NBR—PVC blends without sulfur curing system. Results show that the physicomechanical properties, except resilience, of NBR— PVC blend cured by the electron beam improved by 15% compared with blends cured by the sulfur system.

Modification of Waste Polypropylene with Waste Rubber Dust from Textile Cot Industry and its Characterization

Waste plastics collected from municipality solid waste (MSW), were segregated, washed and dried. The fractions consisting predominantly of polypropylene were further segregated from the lot, cleaned and dried. These were chopped into pieces and then mixed in a Brabender Plasticoder with rubber dust from rubber textile cot industry at various proportions, till homogeneity is achieved. The tensile strength, impact strength and flexural strength of the blends were measured and observed that these properties increasing with increase in loading of rubber dust, reach a maximum at 10 wt% and then decreases. The dynamic mechanical properties of blends such as storage modulus, loss modulus and tan δ measured by DMA-2980 shows an increase in damping characteristics with an increase in the proportion of rubber dust. The rubber dust consists of blends of NBR and PVC used in making textile cots in the textile industry after vulcanization. It is observed that 10% of rubber dust imparts better strength properties with waste PP. The dispersion of the scrap rubber dust in PP has been analysed under SEM and its compatibility has been studied.

Synthesis of EVA-g-MAH and its compatibilization effect to PA11/PVC blends

Ethylene vinyl acetate (EVA) was grafted with maleic anhydride (MAH) to get terpolymer of EVA-g-MAH, and then was employed as a reactive compatibilizer to develop PA11/PVC blends. Mechanical properties indicate the critical EVA-g-MAH content at about 15 wt% and the blending of PVC with PA11 reserves PA11s high performance even at high PVC incorporation. The glass transition temperature change by DMA proves the compatibilization effect. SEM micrographs reveal that PA11/PVC blends have a two-phase structure. Particularly, PA11 is the continuous phase and PVC is the dispersed phase. PVC disperses uniformly in PA11 phase in the presence of EVA-g-MAH, and the increasing PA11 content leads to further decrease of PVC domain size. PA11/PVC blends are compatibilized by in situ reaction between PA11 and EVA-g-MAH, as well as intermolecular specific interactions between EVA-g-MAH and PVC.

Evaluation of the effects of biobased plasticizers on the thermal and mechanical properties of poly(vinyl chloride)

AbstractBlends were prepared of poly(vinyl chloride) (PVC) with four different plasticizers; esters of aconitic, citric, and phthalic acids; and other ingredients used in commercial flexible PVC products. The thermal and mechanical properties of the fresh products and of the products after 6 months of aging were measured. Young's modulus of the PVC blends was reduced about 10‐fold by an increase in the plasticizer level from 15 to 30 phr from the semirigid to the flexible range according to the ASTM classification, but a 40‐phr level was required for PVC to retain its flexibility beyond 6 months. At the 40‐phr level, tributyl aconitate performed better than diisononyl phthalate (DINP) or tributyl citrate, in terms of lowering Young's modulus, both in the fresh materials and those aged for 6 months. The effects of the four plasticizers on the glass‐transition temperature (Tg) were similar, with Tg close to ambient temperature at the 30‐ and 40‐phr levels in freshly prepared samples and at 40–60°C in those aged for 6 months. The thermal stability of the PVC plasticized with DINP was superior among the group. Overall, tributyl aconitate appeared to be a good candidate for use in consumer products where the alleged toxicity of DINP may be an issue. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1366–1373, 2006

Impact properties of acrylate rubber-modified PVC: Influence of temperature

The enhancement of the impact resistance of plastics through the introduction of a rubbery dispersed phase is one of the means to develop high impact strength polymers and has been exploited commercially on a large scale. Rubber-toughened PVC-U or high impact PVC-U is one such important class of rubber-toughened plastics material which has been developed and has a wide application in the building and furniture industries. The type of impact modifiers most commonly used for window frame applications are chlorinated polyethylene, ethylene-vinyl acetate and acrylate modifiers. The current trend shows the importance and popularity of high impact-acrylate-modified PVC. The objective of this research is to extend the existing understanding of toughness enhancement in rubber-toughened polymer materials to acrylate rubber-modified PVC. This paper reports on the effect of temperature on the impact strength of acrylate rubber-modified PVC-U using the instrumented falling weight impact test (IFWI) method. Toughening and fracture mechanism in acrylate-modified PVC were also investigated. The results show that all the acrylate rubber-toughened PVC blends have successfully shifted the ductile–brittle transition points to a lower temperature. However, the impact modifiers were found to differ in their efficiency to shift the ductile to brittle transition. The findings from the SEM study shows that the fibrous yielding phenomenon observed is an indication of the transition of the brittle stage to ductile stage and correlates well with the large increases of the impact strength.

Investigation of Thermodynamic Properties of PIBMA-PVC (50%/50%) and P-4-t-BS-PVC (50%/50%) Blends Systems by Inverse Gas Chromatography

ABSTRACT The specific retention volumes, , values of the poly (isobutyl methacrylate)-poly (vinyl chloride) (PIBMA-PVC) (50%/50%) and poly (-4-tert-butyl styrene)-poly (vinyl chloride) (P-4-t-BS-PVC) (50%/50%) blends-probe systems were calculated between 383 and 423 K by inverse gas chromatography technique. According to these data, the thermodynamic properties such as the sorption enthalpy (), sorption free energy (), sorption entropy (), the partial molar free energy (), and the partial molar heat of mixing, () at infinite dilution were determined for the interactions of (PIBMA-PVC) (50%/50%) and (P-4-t-BS-PVC) (50%/50%) blends with alcohols and aromatics and CHCl3 by inverse gas chromatography method in the temperature range of 383–423 K. The sorption values and values were observed to be exothermic, and , , and values were observed to be endothermic. The values of PIBMA-PVC (50%/50%) and P (-4-t-BS)-PVC (50%/50%) blends-alcohols systems changed from 9.73 to 18.17 kJ/mol and from 10.00 to 16.83 kJ/mol, respectively. Flory-Huggins interaction parameters, χ12, χ13, χ14, χ1(23) and χ1(24) values of PVC, PIBMA, P (4-t-BS), PIBMA-PVC (50%/50%) and P (-4-t-BS)-PVC (50%/50%) blend systems were determined at 413–423 K. In addition, χ23′ and χ24′ values of alcohols changed from 1.191 to 2.473 and from 1.342 to 1.839 for PIBMA-PVC (50%/50%) and P (-4-t-BS)-PVC (50%/50%) blends, respectively, at 413 K.

Properties of Recycled Poly(vinylchloride)/ Acrylonitrile-Butadiene Rubber Blends: The Effect of Maleic Acid

Maleic acid (MAc) was used to improve the compatibility of recycled poly(vi nylchloride)(PVCr)/acrylonitrile-butadiene rubber (NBR) blends. Virgin PVC (PVCv) blends with NBR were also prepared for comparison. The blends were melt mixed using a Haake Rheomix Polydrive R 600/610 at 150 °C and a rotor speed of 50 rpm. It was found that the maleic acid significantly improved the PVCr/NBR blends properties. At a similar blend composition, the PVCr/NBR + MAc blends exhibited a higher peak stress and a higher stress at 100% elongation (M100) but a lower elongation at break and a lower swelling index than ordinary PVCr/NBR blends. Scanning electron microscopy (SEM) of the tensile fracture surfaces of the blends indicated that the maleic acid increased the interfacial interaction between the PVCr and NBR phases, thus improving their compatibility. Differential scanning calorimetry (DSC) indicated that the PVCr/NBR with MAc incorporated had a higher Tg than the PVCr/NBR and PVCv/NBR blends.

Compatibilization of poly(vinyl chloride) with polyamide and with polyolefin by using poly(lauryllactam-random-caprolactam-block-caprolactone)

The compatibilization of various poly(vinyl chloride) (PVC) blends was investigated. The blend systems were PVC-polyamide 12 (PA12), PVC-polypropylene (PP), and PVC-ethylene-propylene-diene rubber (EPDM) with a new compatibilizing agent, random-block terpolymer poly(ω-lauryllactam-random-ϵ-caprolactam-block-ϵ-caprolactone) or systems containing these copolymers. The results were compared to those obtained in previous studies using poly(ω-lauryllactam-block-ϵ-caprolactone) copolymer. The new block copolymer was specially synthesized by reactive extrusion. Observation by scanning electron microscopy (SEM) revealed that compatibilized blends had a finer morphology than the noncompatibilized blends. Addition of 10 weight percent (wt%) of block copolymer proved to be sufficient to give a significant improvement of the mechanical properties of the immiscible PVC blends at room temperature and at high temperatures that were above the glass transition temperature of PVC. For polyolefins, a three-component compatibilizing system including maleated polypropylene, polyamide 12, and block copolymer was used. It was found that poly(ω-lauryllactam-random-ϵ-caprolactam-block-ϵ-caprolactone) was the more efficient compatibilizing agent for the modification of PVC-polyamide 12, PVC-polypropylene, and PVC-ethylene-propylene-diene rubber blends. J. VINYL. ADDIT. TECHNOL., 11:95–110, 2005. © 2005 Society of Plastics Engineers

Alloying of poly(vinyl chloride) to reduce plasticizer migration

AbstractConcern over the migration of low molecular weight plasticizer from flexible poly(vinyl chloride) (PVC) used in toys and medical products has spearheaded the commercialization of a number of plasticizing polymers. In this study the plasticizing behavior of an ethylene/vinyl acetate/carbon monoxide terpolymer (Elvaloy® from DuPont) was investigated. Blends of PVC, Elvaloy 742, and dioctyl phthalate (DOP) were processed on a twin‐roll mill and compression molded into plaques. These materials were characterized in terms of their hardness, glass‐transition temperature (Tg), clarity, mechanical properties, and plasticizer migration behavior. The ratios of PVC/DOP/Elvaloy investigated were determined by experimental design. Using this approach it was possible to model the results and produce contour plots to map out the properties of a wide range of formulations. It was confirmed that Elvaloy 742 is compatible with PVC and has a plasticizing effect: this was demonstrated both in terms of a reduction in Shore A hardness and a reduction in Tg. Plasticizer migration was reduced in proportion to the amount of liquid plasticizer replaced. Plasticizing with Elvaloy gave an improvement in tear strength. However, at constant hardness there was no improvement in tensile strength from replacing DOP with Elvaloy. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 2022–2031, 2004

Preparation and thermomechanical characterization of poly(vinyl chloride) blends compatible with terpolymer‐containing maleic anhydride

AbstractIn this study, I aimed to change the thermomechanical characteristics of poly(vinyl chloride) (PVC), which is widely used in commercial areas. Copolymers containing maleic anhydride (MA) units are commonly used to obtain compatible polymer blends. In our study, PVC blends were also prepared with the terpolymers with and without anhydride units. I assumed that the impact of the terpolymer on the thermomechanical characteristics of the PVC material could be more effectively controlled. For this purpose, two sets of six different blends of PVC with or without MA were synthesized, among which one was pure PVC, but the other five blends contained 2, 4, 6, 8, and 10% terpolymer. In conclusion, I observed that the terpolymer with the MA unit more regularly changed the thermomechanical characteristics of PVC. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1586–1589, 2004

The influence of core–shell structured modifiers on the toughness of poly (vinyl chloride)

The core–shell structured grafted copolymer particles of polybutadiene grafted polymethyl methacrylate (PB-g-PMMA, MB) were prepared by emulsion polymerization. The MB particles were used to modify poly (vinyl chloride) (PVC) by melt blending. The mechanical properties of the PVC blends were investigated. The micro-morphology of the PVC blends was observed by scanning electron microscopy (SEM). The results indicated that the samples with the best impact strength could be obtained when the core–shell weight ratio of PB to PMMA is lower than 93:7, the mechanical properties correlated well with SEM morphologies, the addition of modifier with the ratio core to shell of 93:7 could reduce the domain size of the dispersed phase. Furthermore, the compatibility and properties of the blends were greatly enhanced and improved. The modifier particles could be well dispersed in the PVC matrix.

Ternary Blends to Improve Heat Distortion Temperature and Rheological Properties of PVC

AbstractSummary: Binary and ternary blends of PVC mixed with α‐methylstyrene/acrylonitrile‐butadiene‐styrene copolymer (AMS‐ABS) and ethylene/vinyl acetate/carbon monoxide terpolymer (EVA‐CO) are investigated, with the aim to obtain a new PVC based material with an improved heat distortion temperature and good processability. Dynamic Mechanical Thermal Analysis (DMTA) reveals that ternary PVC/AMS‐ABS/EVA‐CO blends exhibit two glass transition temperatures: the lower Tg corresponds to a PVC/EVA‐CO phase and the higher one to a PVC/AMS‐ABS phase. An analysis of PVC respective interactions with AMS‐ABS and EVA‐CO leads to assert that the distribution of PVC in the ternary PVC/AMS‐ABS/EVA‐CO system is basically controlled by the binary immiscible blend composition, taken as Φ AMS‐ABS/Φ EVA‐CO ratio. The inclusion of AMS‐ABS and EVA‐CO to form ternary blends based on PVC, allows to improve heat distortion temperature (owed to the presence of AMS‐ABS), maintaining a low viscosity in the molten state, due to the plasticizing effect of EVA‐CO.Viscosity function obtained at T = 170 °C from extrusion capillary measurements.magnified imageViscosity function obtained at T = 170 °C from extrusion capillary measurements.

Blends of poly(vinyl chloride) (PVC)/natural rubber‐g‐(styrene‐co‐methyl methacrylate) for improved impact resistance of PVC

AbstractTo improve the mechanical properties of poly(vinyl chloride) (PVC), the possibility of combining PVC with elastomers was considered. Modification of natural rubber (NR) by graft copolymerization with methyl methacrylate (MMA) and styrene (St) was carried out by emulsion polymerization by using redox initiator to provide an impact modifier for PVC. The impact resistance, dynamic mechanical analysis (DMA), and scanning electron microscopy (SEM) of St and MMA grafted NR [NR‐g‐(St‐co‐MMA)]/PVC (graft copolymer product contents of 5, 10, and 15%) blends were investigated as a function of the amount of graft copolymer product. It was found that the impact strength of blends was increased with an increase of the graft copolymer product content. DMA studies showed that NR‐g‐(St‐co‐MMA) has partial compatibility with PVC. SEM confirmed a shift from brittle failure to ductility with an increase graft copolymer content in the blends. The mechanical properties showed that NR‐g‐(St‐co‐MMA) interacts well with PVC and can also be used as an impact modifier for PVC. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 1666–1672, 2004

Diffusion and partition coefficients of small organic solvents in molten miscible polymer blends: Correlations with thermodynamic interactions

AbstractThe transport properties of small organic molecules in molten poly(vinyl chloride) (PVC)/atactic poly(methyl methacrylate) (PMMA) blends and their homopolymers were studied with inverse gas chromatography. The elution profiles resulting from various organic solvents and different experimental conditions were used for measuring diffusion and partition coefficients. With the van Deemter equation and retention volumes at infinite dilution, diffusion coefficients of 10−7 to 10−8 cm2/s and partition coefficients of 10–50 were calculated. The dependence of the diffusion and partition coefficients on experimental variables such as the blend concentration, temperature, and solute nature was examined. The presence of PMMA in PVC blends affected the sorption behavior of the PVC matrix up to a certain concentration. Beyond that, it was hard to derive any composition–diffusivity dependence. On the contrary, the diffusion and partition coefficients were greatly influenced by changes in the temperature and by the nature of the solute. For those solutes (e.g., chlorinated hydrocarbons) showing stronger interactions with polymer blends (higher negative values for the Flory–Huggins interaction parameter χ1(23)), higher diffusion and partition coefficients were obtained. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 267–279, 2004

Compatibilized blends of PVC/PA12 and PVC/PP containing poly(lauryl lactam‐block‐caprolactone)

AbstractSpecially designed block copolymers have played a role as compatibilizing agents in the system of immiscible polymer blends. We applied lauryl lactam (LA)–caprolactone (CL) block copolymer [P(LA‐b‐CL)] as a compatibilizing agent for immiscible poly(vinyl chloride) (PVC) blends with various polymers. These blends possess high thermal performance and toughness. We investigated the effect of P(LA‐b‐CL) as a compatibilizing agent for immiscible PVC blends with poly(ω‐lauryl lactam) [polyamide 12 (PA12)]. We also described the invention of a new compatibilizing agent system involving P(LA‐b‐CL) for PVC/polypropylene (PP) blends. The mechanical and thermal properties of (1) PVC/PA12 blend compatibilized with P(LA‐b‐CL) and (2) PVC/PP blend compatibilized with P(LA‐b‐CL)/PA12/maleic anhydride–modified PP were both enhanced. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1983‐1992, 2004

N‐Butyl acrylate based latex interpenetrating polymer networks used as processing modifiers and impact modifiers of poly(vinyl chloride)

AbstractA latex interpenetrating polymer network (LIPN), consisting of poly(n‐butyl acrylate), poly(n‐butyl acrylate‐co‐ethylhexyl acrylate), and poly(methyl methacrylate‐co‐ethyl acrylate) and labeled PBEM, with 1,4‐butanediol diacrylate as a crosslinking agent was synthesized by three‐stage emulsion polymerization. The initial poly(n‐butyl acrylate) latex was agglomerated by a polymer latex containing an acrylic acid residue and then was encapsulated by poly(n‐butyl acrylate‐co‐ethylhexyl acrylate) and poly(methyl methacrylate‐co‐ethyl acrylate). A polyblend of poly(vinyl chloride) (PVC) and PBEM was prepared through the blending of PVC and PBEM. The morphology and properties of the polyblend were studied. The experimental results showed that the processability and impact resistance of PVC could be enhanced considerably by the blending of 6–10 phr PBEM. This three‐stage LIPN PBEM is a promising modifier for manufacturing rigid PVC. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1168–1173, 2004

FT‐IR Investigation into the miscible interactions in new materials for optical devices

AbstractIn this article we determine the miscibility of azobenzene derivative (poly(4‐(N‐(2‐methacryloyloxyethyl)‐N‐ethylamino)‐4′‐nitroazobenzene)90‐co‐(methyl methacrylate)10)/poly(vinyl acetate) (PVAc) and azobenzene derivative/poly(vinyl chloride) (PVC) blends using Fourier Transform infrared (FT‐IR) spectroscopy. With this method we can clearly identify the exact interactions responsible for miscibility. In the azobenzene derivative 50:50PVAc blend new peaks were evident at 2960, 2890, 1237 and 959 cm−1, these peaks depict miscible interactions. These wavenumbers indicate that the miscible interactions occurring are from the CH stretching band, the vinyl acetate CO, conjugated to the ester carbonyl, the cis‐transformation NN stretch frequency and the acetate ester weak doublet. The azobenzene derivative 80:20PVC blend display peaks identical in profile to the blend homopolymers, indicating no miscible interactions. However, this could be due to overlapping of peaks within the same wavenumber region, making resolution difficult.This research demonstrates FT‐IR can deduce favorable interactions for miscibility and therefore numerous miscible blends can successfully be calculated if possessing the same groups responsible for miscibility. This paves the way for a new generation of designer optical materials with the desired properties. Copyright © 2003 John Wiley & Sons, Ltd.

Studies on mechanical and rheological properties of poly(vinyl chloride) modified with elastomers and rigid organic particles

AbstractChlorinated polypropylene (CPP) as rigid organic particles and chlorinated polyethylene (CPE) as elastomer were used to modify the properties of poly(vinyl chloride) (PVC) by melt blending. Both mechanical and rheological properties of the PVC blends were investigated. The submicroscopic morphology of the blends was observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results demonstrate that when the weight ratio of CPE to CPP is about 6 : 1, a sample with the best impact strength and without obvious decline in tensile strength can be obtained. The impact strength correlates well with SEM morphologies, and TEM micrographs in the necking of the tensile specimen indicate that a cold‐drawing deformation of rigid particles happens as reported by T. Kurauchi and T. Ohta (J Mater Sci 1984, 19, 1699). Therefore, a conclusion can be drawn that CPP particles acting similar to elastic particles can toughen PVC, and the cold‐drawing deformation is the primary reason for toughening the PVC blends. In addition, the addition of CPP can promote the processibility of PVC ternary blends. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2478–2483, 2003

Influence of core–Shell structured particles on the impact resistance of poly(vinyl chloride)

AbstractThe core–shell structured particles which comprise rubbery and glassy layers were prepared by emulsifier‐free emulsion polymerization of poly(n‐butyl acrylate/methyl methacrylate)/poly(methyl methacrylate/n‐butyl acrylate) [P(BA/MMA)/P(MMA/BA)]. The core–shell structured particle toughened PVC blends were investigated in detail. Impact strength, elongation at break and the related mechanical properties were measured for further evaluation of the toughening efficiency. Copyright © 2003 John Wiley & Sons, Ltd.