The miscibility of polyacrylates and polymethacrylates with PVC: In situ polymerization and the miscibility of poly(methyl acrylate) and poly(ethyl acrylate) with PVC

The in situ polymerization of vinyl chloride with various polyacrylates and polymethacrylates has been studied. The products were examined by dynamic mechanical analysis. Poly(methyl acrylate) and poly(ethyl acrylate) had previously produced two-phase blends with poly(vinyl chloride) (PVC) by solvent casting, but poly(ethyl acrylate) was shown to be miscible with PVC when blends were produced by in situ polymerization. Poly(methyl acrylate) and poly(octyl acrylate) were found to be immiscible with PVC whereas other polyacrylates and polymethacrylates with intermediate ester group concentrations were found to be miscible, confirming previous studies. The glass transition temperatures of the blends were measured and the deviations from the expected mean of the two base polymers were calculated as an indication of the strength of interaction between the polymers. The polymers having intermediate ester group concentrations showed the strongest interactions and the results correlated well with previously measured interaction parameters.     

Compatibility of polyacrylates and polymethacrylates with poly(vinyl chloride): 1. Compatibility and temperature variation

Mixtures of a series of polymethacrylates and polyacrylates with PVC were prepared by solvent casting from methyl ethyl ketone. Some mixtures were also prepared by mechanical mixing and in situ polymerization (polymerization of vinyl chloride monomer in the presence of the other polymer). The mixtures were assessed for compatibility by dynamic mechanical measurements and optical clarity. It was found that all polymethacrylates from poly(methyl methacrylate) to poly(n-hexyl methacrylate) were compatible with PVC as were poly(n-propyl acrylate) and poly(n-butyl acrylate). Higher chain polyacrylates are incompatible. Poly(methyl acrylate) and poly(ethyl acrylate) appear incompatible with PVC when mixtures are prepared by solvent casting, but compatible when prepared by in situ polymerization, and mechanical mixtures show some sign of compatibility. It seems possible that in this case the solvent interferes with the compatibility. Mixtures of PVC with poly(n-hexyl methacrylate), poly(n-butyl acrylate) and poly(n-propyl acrylate) phase separate when heated in the region between 100°C and 160°C indicating the existence of a lower critical solution temperature.     

Comparative studies on the use of gas chromatographic and vapour pressure techniques for the determination of the interaction energy parameter

Comparative studies using gas chromatographic and vapour pressure techniques have been carried out on solutions of poly(vinyl chloride), polystyrene, and poly(methyl methacrylate) in the solvents toluene, methyl ethyl ketone, 1,4 dioxan, tetrahydrofuran and di-n-propyl ether. The values of the corresponding interaction energy parameters (χ₁) are compared and analysed in terms of the Flory-Huggins theory of polymer solutions. The two techniques produced values of χ₁ for a wide range of solvents which were in good agreement with each other, thus substantiating the validity of both methods. Also, the vapour pressure results agreed with the Flory-Huggins theory over an extended range of solute composition. The gas chromatographic method yielded very self-consistent results and proved to be the more rapid technique. It also had the advantage that it could be used without much difficulty over a wider temperature range.     

Investigation of the compatibility of butadiene—acrylonitrile copolymers with poly(vinyl chloride)

Various methods were used to study the compatibility of butadiene-acrylonitrile copolymers with poly(vinyl chloride). These blends were investigated by phase contrast microscopy, differential scanning calorimetry and torsion pendulum analysis. We conclude that the copolymers are compatible with poly(vinyl chloride) in all PVC compositions within the range 23–45% acrylonitrile. These blends exhibit a single T_g in the torsion pendulum studies and differential scanning calorimetry studies and follow a Fox expression in the variation of T_g with composition. Experimental densities are also higher than those calculated assuming volume additivity, implying better packing and a negative heat of mixing leading to molecular compatibility.     

Miscibility in PVC-polyester blends

Blends of poly(vinyl chloride), PVC, with the polyesters poly(butylene adipate), poly(hexamethylene sebacate), poly(2,2-dimethyl,1,3-propylene succinate) and poly(1,4-cyclohexanedimethanol succinate) were found to exhibit a single, composition dependent glass transition. Thus, these polyesters are miscible with PVC as others have reported for poly(?-caprolactone). However, mixtures of poly(ethylene succinate), poly(ethylene adipate) and poly(ethylene orthophthalate) with PVC were found not to be miscible. Melting point depression has been used to estimate the blend interaction parameter. These results combined with others from the literature suggest that there is an optimum density of ester groups in the polymer chain for achieving maximum interaction with PVC. Too few or too many ester groups result in immiscibility with PVC.     

Studies of polyester/chlorinated poly(vinyl chloride) blends

Chlorinated poly(vinyl chloride) (CPVC) was solution blended with poly(caprolactone) (PCL), poly(hexamethylene sebacate) (PHMS), poly(α-methyl-α-n-propyl-β-propiolactone) (PMPPL), poly(valerolactone) (PVL), poly(ethylene adipate), poly(ethylene succinate) and poly(β-propiolactone). From calorimetric glass transition temperature (T_g) measurements, it is concluded that CPVC is miscible with polyesters having a CH₂/COO ratio larger than three (PCL, PHMS, PMPPL and PVL). The Gordon-Taylor k parameter was also calculated and found equal to 1.0 and 0.56 for PCL/CPVC and PHMS/CPVC blends, respectively. From these values, it is concluded that CPVC gives a stronger interaction with polyesters than poly(vinyl chloride) due to its larger chlorine content.     

A Viscometric Study of the Miscibility Behaviour of Poly(N-Vinyl Pyrrolidone) Blends

The miscibility behaviour of blends of poly(N-vinyl pyrrolidone) (PVP) with poly(vinyl chloride) (PVC), poly(vinyl acetate) (PVAc) and vinyl chloride–vinyl acetate (VCVAc) copolymer has been investigated on the basis of a viscometric approach. PVP is found to be miscible with PVC over the entire composition range, as is evident from the high values observed for the intrinsic viscosity of transfer. This is further supported by the single glass transition temperature observed in differential scanning calorimetry studies of the blend films. Blends of PVP with VCVAc copolymer exhibit microphase separation which is shown clearly in the scanning electron micrographs of the films. PVAc/PVP blends show interaction only at low PVAc contents, but in general are immiscible. © of SCI.     

Chlorination of poly(vinyl chloride) model compounds in radical‐complexing solvents

A potential route to the preparation of poly(1,2‐dichloroethylene) by the selective chlorination of poly(vinyl chloride) (PVC) was explored. During free‐radical chlorinations with Cl₂, certain solvents play the very important role of forming complexes with the free chlorine atom that lead to changes in the pattern of chlorine substitution. In our work, the photochlorination of three model compounds for PVC, namely, 2,4‐dichloropentane, 3‐chloropentane, and 4‐chloroheptane, was carried out with molecular chlorine in the absence or presence of complexing solvents. The effects of these solvents on the chlorination selectivity were determined. During the conventional chlorination of sec‐alkyl chlorides with molecular chlorine, bridged‐radical intermediates are believed to be involved. They lead to vicinal dichlorides as the major products. However, we found that complexing solvents significantly increased the yields of geminal dichlorides instead. Such solvents also are well known to decrease reactivity in free‐radical chlorinations with Cl₂. Thus, for both of these reasons, the chlorination of PVC with Cl₂ in complexing solvents is unlikely to be useful for the preparation of poly(1,2‐dichloroethylene). J. VINYL ADDIT. TECHNOL., 22:405–409, 2016. © 2015 Society of Plastics Engineers     

Diffusion of vinyl chloride from PVC packaging material into food simulating solvents

Two models are used to describe vinyl chloride monomer (VCM) diffusion from poly(vinyl chloride) (PVC) packages to food simulating solvents. It was found that when the initial solid concentration in a PVC package is 0,35 ppm: (a) For poor solvents such as water and oils, VCM concentration in the solvent, C_l, theoretically will not exceed 20 ppb. (b) For strong solvents, the volume ratio of package solid/solvent should not exceed 0.1 in order to keep (C_l)_max below 20 ppb. (c) It was demonstrated that thickness can be adjusted to give a C_l = 20 ppb at the time equal to the shelf-life of the package. The method can also be used to calculate the initial concentration of VCM in a package which will give a proposed level of maximum C_l when the solvent and package geometry are fixed. VCM diffusion from PVC pressure pipe to pipe fluids was similarly analyzed.     

Influence of tacticity of poly(methyl methacrylate) on the compatibility with poly(vinyl chloride)

Blends of conventional poly(vinyl chloride) (PVC) and poly(methyl methacrylate) (PMMA) with different tacticities were obtained both from the bulk and from solution. The glass transition temperatures (T_g) of the blends were determined with a differential scanning calorimeter and by dynamic mechanical measurements. Some turbidity measurements on films and viscosity measurements on mixed solutions supplied additional information about the state of mixing. From the results it appeared that isotactic (i-)PMMA and PVC form an incompatible system over the entire composition range (two T_g's), whereas blends of syndiotactic (s-)PMMA and PVC form a compatible system up to a composition corresponding with a monomer unit ratio of about 1:1. For higher s-PMMA contents phase separation is observed; one phase corresponding with the 1:1 s-PMMA—PVC associate and the other phase representing the excess of pure s-PMMA. This effect of tacticity is discussed in terms of the differences in chain conformation of i- and s-PMMA.     

Synthesis and polymerization of fluorinated,chlorinated and deuterated vinyl carbonates

The present paper deals essentially with the synthesis of new fluorinated and chlorinated poly(vinylcarbonates). Vinyl carbonates, CH₂=CH-O-CO₂R (where R=CH₂CCl₃, CH₂CF₃, C₂H₄C₆F₁₃ and CD₃) were first prepared by reacting vinyl chloroformate with the corresponding alcohols. Their structures were identified by¹³C NMR. The action of ultraviolet light on these monomers resulted in the corresponding polycarbonates, the refractive indexes and Tg of which were measured. Polycarbonates possess Tg values between those of polyacrylates and polymethacrylates which contain the same substituents.     

Miscibility of C60-end-capped poly(ethylene oxide) with poly(vinyl chloride)

The miscibility of blends of single [60]fullerene (C₆₀)-end-capped poly(ethylene oxide) (FPEO) or double C₆₀-end-capped poly(ethylene oxide) (FPEOF) with poly(vinyl chloride) (PVC) has been studied. Similar to poly(ethylene oxide) (PEO), both FPEO and FPEOF are also miscible with PVC over the entire composition range. X-ray photoelectron spectroscopy showed the development of a new low-binding-energy Cl2p doublet and a new high-binding-energy O1s peak in FPEO/PVC blends. The results show that the miscibility between FPEO and PVC arises from hydrogen bonding interaction between the α-hydrogen of PVC and the ether oxygen of FPEO. From the melting point depression of PEO, FPEO or FPEOF in the blends, the Flory-Huggins interaction parameters were found to be −0.169, −0.142, −0.093 for PVC/PEO, PVC/FPEO and PVC/FPEOF, respectively, demonstrating that all the three blend systems are miscible in the melt. However, the incorporation of C₆₀ slightly impairs the interaction between PEO and PVC.     

Processability and characterization of poly(vinyl chloride)‐b‐poly(n‐butyl acrylate)‐b‐poly(vinyl chloride) prepared by living radical polymerization of vinyl chloride. Comparison with a flexible commercial resin formulation prepared with PVC and dioctyl phthalate

This work reports the synthesis and processing of a new flexible material based on PVC produced by living radical polymerization. The synthesis was carried out in a two‐step process. In the first step the macroinitiator α, ω‐di(iodo)poly(butyl acrylate) [α, ω‐di(iodo)PBA] was synthesized in water by single electron transfer/degenerative chain transfer mediated living radical polymerization (SET‐DTLRP) catalyzed by Na₂S₂O₄. In the second step this macroinitiator was reinitiated by SET‐DTLRP of vinyl chloride (VC), thereby leading to the formation of the block copolymer poly(vinyl chloride)‐b‐poly(butyl acrylate)‐b‐poly(vinyl chloride) [PVC‐b‐PBA‐b‐PVC]. This new material was processed on a laboratory scale. The DMTA traces showed only a single glass transition temperature, thus indicating that no phase segregation was present. The copolymers were studied with regard to their processing, miscibility, and mechanical properties. The first comparison with commercial formulations made with PVC and dioctyl phthalate (DOP) is presented. J. VINYL ADDIT. TECHNOL., 12:156–165, 2006. © 2006 Society of Plastics Engineers     

Tensile,stress-strain and creep rupture properties of poly (vinyl chloride)/poly(neopentyl glycol adipate)/poly(vinylidene fluoride) blends

Poly (vinyl chloride), PVC, and poly(vinylidene fluoride), PVDF, are incompatible polymers. Poly(neopentyl glycol adipate), PDPA, is miscible with both PVC and PVDF. With PDPA acting as a compatibilizer between PVC and PVDF. compatible PVC/PDPA/PVDF blends can be formed at PVDF content of about less than 50wt%. Above 50wt% PVDF the ternary blends exist in two phases exhibiting two glass transition temperatures, T_g, PVC is the main contributor to the mechanical strength while PDPA and PVDF contribute to the elastic properties of these blends. A compatible blend of 55/22.5/22.5 wt% PVC/PDPA/PVDF exhibiting one single T_g appears to show an interesting balance of the properties of the blend components.     

Wide angle X-ray diffraction investigation of crystal orientation in miscible blend of poly(ε-caprolactone)/poly(vinyl chloride) crystallized under strain

The orientation of poly(ε-caprolactone) crystals in miscible poly(ε-caprolactone)/poly(vinyl chloride) (PCL/PVC) blends, melt crystallized under strain, has been studied by wide angle X-ray diffraction (WAXD). At low draw ratios or low PVC contents, all the observable (hk0) crystal reflections orient towards the meridional direction in WAXD patterns, indicating the presence of ring-fibre orientation. With the increase of draw ratio or PVC content, additional crystal orientation with the crystal a-axis parallel to the stretching direction is found to superimpose on the WAXD pattern of ring-fibre orientation. Both the ring-fibre orientation, which dominates the WAXD pattern, and the a-axis orientation are characterized by the perpendicular orientation of the crystal c-axis to the stretching direction. The unusual PCL orientation is a consequence of the combined effects of both the stretching and the presence of PVC in the PCL/PVC blends.     

Electrode kinetics of the O2/O2 redox couple at Hg electrode in the presence of PVC in aprotic media

The kinetic and thermodynamic parameters of the O₂/O₂⁻ redox couple at a mercury electrode in various aprotic solvents have been evaluated by normal pulse polarography and cyclic voltammetry in the presence of poly(vinyl chloride) (PVC) as a maximum suppressor. The polarographic maxima were observed on the rising portion of polarogram for O₂ reduction, but they are completely suppressed by the addition of a small amount of PVC. The adsorption behavior of PVC on a hanging mercury drop electrode is examined based on the measurement of the differential capacitance of the electrical double layer. The relevant kinetic and thermodynamic parameters, i.e., the standard rate constant, k°, the cathodic transfer coefficient, α_c, and the formal potential, E°′ of the O₂/O₂⁻ redox couple were estimated together with the diffusion coefficients of O₂, DO₂. An excellent linear relationship between the formal potential and solvent's acceptor number was found.     

Internal plasticization of poly(vinyl chloride) by grafting acrylate copolymers via copper-mediated atom transfer radical polymerization

Internal plasticization of poly(vinyl chloride) (PVC) was achieved in one-step using copper-mediated atom transfer radical polymerization to graft different ratios of random n-butyl acrylate and 2–2-(2-ethoxyethoxy)ethyl acrylate copolymers from defect sites on the PVC chain. Five graft polymers were made with different ratios of poly(butyl acrylate) (PBA) and poly(2–2-(2-ethoxyethoxy)ethyl acrylate) (P2EEA); the glass transition temperatures (T_g) of functionalized PVC polymers range from − 25 to − 50°C. Single T_g values were observed for all polymers, indicating good compatibility between PVC and grafted chains, with no evidence of microphase separation. Plasticization efficiency is higher for polyether P2EEA moieties compared with PBA components. The resultant PVC graft copolymers are thermally more stable compared to unmodified PVC. Increasing the reaction scale from 2 to 14 g produces consistent and reproducible results, suggesting this method could be applicable on an industrial scale.     

Flexibilität und thermodynamische Eigenschaften von Polyacrylaten,Polymethacrylaten und statistischen Acrylat/Methacrylat-Copolymeren 2. knäuelparameter

Flexibility and interaction parameters of the polymers have been calculated from the results of light-scattering and viscosity measurements with polyacrylates, polymethacrylates and random copolymers of methyl methacrylate with acrylates and n-butyl methacrylate. Only slight differences are found when the chain rigidity of polyacrylates is compared with that of polymethacrylates. There is however a clearcinfluence of the ester alkylgroup. With increasing size of the ester alcohol the polymer chain gets more rigid. In case of copolymers the chain flexibility does not result simply from the homopolymer values. The measured values don't reveal a systematic connection, moreover in case of copolymers there is a strong influence of solvents on the unperturbed dimensions. The repulsive powers occuring in the copolymer coil due to hetero-contacts have been characterized quantitatively. The graduaeion which was found coincides with compatibility tests of the corresponding homopolymers in a concentrated solution : the more intense the expansion of the copolymer coil caused by heterocontacts, the lower the concentration where a demixing of the homopolymers is observed.     

Blends containing polymers of epichlorohydrin and ethylene oxide. II. Polyacrylates

The phase behavior of blends of various polyacrylate homopolymers and two commercial ethyl acrylate (EA) and n-butyl acrylate (nBA) copolymers with polyepichlorohydrin (PECH), poly(ethylene oxide) (PEO), and a copolymer of epichlorohydrin and ethylene oxide [P(ECH/EO)] was examined using differential scanning calorimetry and optical indications of phase separation on heating, i.e., lower critical solution temperature (LCST) behavior. Poly(methylacrylate) (PMA) was shown to be miscible with PECH, PEO, and P(ECH/EO) while only PECH was found to be miscible with the higher polyacrylates: poly(ethyl acrylate), EA copolymer, poly(n-propyl acrylate), and nBA copolymer. However, even PECH was found to be only partially miscible with poly(n-butyl acrylate). In general, glass transitions observed by DSC for blends were not as broad as those found in corresponding polymethacrylate blends. All mixtures showed LCST behavior, and, based on this and excess volume measurements, to the extent possible, qualitative conclusions were made concerning the relative strength of the interactions among the various blend pairs. For PECH it appears that the interaction with polyacrylates decreases with increasing size of the alkyl group. The commercial copolymers seem to interact more exothermically with PECH than the corresponding homopolymers. The interaction with PMA is apparently larger for PECH than for PEO or for P(ECH/EO). Interactions for the latter two are about the same. The apparently exothermic interactions between ECH and EO units are not sufficiently strong to preclude miscibility of P(ECH/EO) with PMA. As for the polymethacrylates, it is clear that the chlorine moeity of PECH is needed for miscibility with higher polyacrylates.     

Study of the solvent effect on miscibility between poly(vinyl chloride) and poly(methyl methacrylate) in the solution state – viscometric measurements

In this work, the solvent effect on the miscibility between poly(vinyl chloride) (PVC) and poly(methyl methacrylate) (PMMA) in ternary polymer solutions was examined by the viscometric method. In these systems, we could understand that the used solvents, tetrahydrofuran (THF) or N,N‐dimethylformamide (DMF), mainly affect the interaction between PVC and PMMA, while prompting various miscible properties. In PVC/PMMA/THF solution, THF is a near θ‐solvent and a poor solvent for PVC and PMMA, respectively. The mixing of the tighter PMMA coils and more extended PVC coils in THF may cause the sea–island heterogeneous structure below the weight fraction of PMMA in the polymer mixture w_PMMA = 0.7, resulting in immiscible PVC/PMMA mixtures. At w_PMMA ≥ 0.7, the PVC/PMMA mixtures are relatively miscible, giving homogeneous polymer solutions. It means that the miscibility between PVC and PMMA depends on the composition of polymer mixture. However, due to the similar affinity of DMF to PVC and PMMA, PVC/PMMA/DMF solutions exhibit high miscibility between PVC and PMMA at about w_PMMA = 0.5. © 2000 Society of Chemical Industry