Properties of Poly(vinyl chloride)/poly(ethylene oxide)/polyaniline Conductive Films: The Effect of Poly(ethylene glycol) Diglycidyl Ether

The effect of polyaniline and poly(ethylene glycol) diglycidyl ether on tensile properties, morphology, thermal degradation, and electrical conductivity of poly(vinyl chloride)/poly(ethylene oxide)/polyaniline conductive films was studied. The poly(vinyl chloride)/poly(ethylene oxide)/polyaniline conductive films were prepared using a solution casting technique at room temperature until a homogeneous solution was produced. Poly(vinyl chloride)/poly(ethylene oxide)/polyaniline/poly(ethylene glycol) diglycidyl ether conductive films exhibit higher electrical properties, tensile strength, modulus of elasticity but lower final decomposition temperature than poly(vinyl chloride)/poly(ethylene oxide)/polyaniline conductive films. Scanning electron microscopy morphology showed that the polyaniline more widely dispersed in the poly(vinyl chloride)/poly(ethylene oxide) blends with the addition of poly(ethylene glycol) diglycidyl ether as surface modifier.     

Thermal degradation of poly(vinyl chloride) blends

Poly(vinyl chloride) was mixed with various poly(methacrylate)s and polycarbonates by combined precipitation from common solutions. The thermal stability of the samples was measured at 180°C under nitrogen, the HCl evolved was detected by conductometry. UV-Vis-spectra of degraded samples were measured to investigate the influence of the poly(methacrylate)s on the lengths of polyenes formed during the degradation of poly(vinyl chloride). The experiments show that the nature of the ester group is the dominating factor for the thermal stability of poly(vinyl chloride) in these blends. Poly(n-butylmethacrylate) exhibits the best stabilization for poly(vinyl chloride) in this series. Polycarbonates with a higher glass transition temperature than the temperature of degradation destabilize poly(vinyl chloride). Stabilization experiments with dibutyltin-bis(isooctylthioglycolate) show a costabilizing effect of the poly(methacrylate)s and polycarbonates.     

Thermal dehydrochlorination of poly(vinyl chloride). I. Effect of iron oxide on the rate of dehydrochlorination

The thermal degradation of poly(vinyl chloride) (PVC) was studied by following the rates of dehydrochlorination at temperatures between 180°C in pure nitrogen and air flow. Iron oxide accelerates the elimination of hydrogen chloride from PVC. The accelerating effect depends on the concentration of the oxide, and it has a maximum. This work tried to explain these behaviors. A mechanism of dehydrochlorination is suggested for polymer containing iron oxide.     

聚氯乙烯热稳定剂甘油基钙/锌的制备及性能研究

用氧化钙、氧化锌与甘油反应分别制备了甘油钙、甘油锌。通过刚果红法和电导法考察了甘油钙/锌在聚氯乙(烯PVC)制品中的热稳定性能,并研究了甘油钙和甘油锌之间的协同效应。结果表明:甘油钙与甘油锌的质量比为4/1时,PVC的热稳定时间可达90 min,远远超出传统的硬脂酸钙/锌的17.8 min,具有优良的长期热稳定性。热分解表观动力学数据表明甘,油钙/锌的加入使PVC的稳定性增强。     

Vinyl chloride formation from the thermal degradation of poly(vinyl chloride)

The volatile products from the thermal degradation of poly(vinyl chloride) (PVC) resins and compounds are shown to contain trace amounts of vinyl chloride. Data presented show the effect of temperature and resin type on the amount of vinyl chloride formed. At the maximum temperatures involved in PVC processing which may reach 210°C, vinyl chloride monomer (VCM) evolution amounts to less than 1 ppm (resin basis). A technique employing a thermogravimetric balance and charcoal adsorption of volatiles is described for studying thermal degradation of PVC. The volatiles are analyzed for vinyl chloride by gas chromatography. Peak identity was confirmed by mass spectrometry.     

Oxidative thermal decomposition of poly(vinyl chloride) compositions

“Pure” poly(vinyl chloride) resin and four compositions containing poly(vinyl chloride) were subjected to oxidative thermal degradation in air at &400°C both in a quiescent and a flow system. The volatiles formed were identified and quantitatively determined on a gram-per-gram basis. Hydrogen chloride was the main product found. The nature and relative concentration of the produced organic chlorinated species appeared to be dependent not only on the poly(vinyl chloride) constituent but also on the other ingredients. All the compositions contained phthalate ester plasticizers. In the dynamic system, these distilled largely unchanged, whereas under static conditions transformation into phthalic anhydride occurred.     

Novel Strategy for Anhydride-Functionalization of Poly(Vinyl Chloride): Synthesis and Characterization

A new strategy for anhydride-functionalization of poly(vinyl chloride) is suggested. First, some chlorine groups of poly(vinyl chloride) were converted to phenylamine-oxy groups by a nucleophilic substitution reaction in the presence of a solvent composed of 4-aminophenol, K₂CO₃, and dry N,N-dimethylformamide at room temperature, to avoid cross-linking. The phenylamine-functionalized poly(vinyl chloride) was further reacted with maleic and 1,2,4-benzenetricarboxylic acid anhydrides. The chemical structures of all samples as representatives were characterized by Fourier transform infrared and nuclear magnetic resonance spectroscopies. The chemical compositions of the synthesized anhydride-functionalized poly(vinyl chloride) were investigated by elemental analysis, and their thermal behaviors were characterized by means of differential scanning calorimetry and thermogravimetric analyzer.     

Vinyl chloride formation from the thermal degradation of poly(vinyl chloride)

The volatile products from the thermal degradation of poly(vinyl chloride) (PVC) resins and compounds are shown to contain trace amounts of vinyl chloride. Data presented show the effect of temperature and resin type on the amount of vinyl chloride formed. At the maximum temperatures involved in PVC processing which may reach 210°C., vinyl chloride monomer (VCM) evolution amounts to less than 1 ppm (resin basis). A technique employing a thermogravimetric balance and charcoal adsorption of volatiles is described for studying thermal degradation of PVC. The volatiles are analyzed for vinyl chloride by gas chromatography. Peak identity was confirmed by mass spectrometry.     

Sensory irritation evoked by the thermal decomposition products of plasticized poly(vinyl chloride)

A decrease in respiratory rate in mice during exposure to irritating airborne chemicals has been utilized as a response parameter to characterize the degree of upper respiratory tract irritation (sensory irritation) to the thermal decomposition products of plasticized poly(vinyl chloride). The plasticized poly(vinyl chloride) was placed in a low mass vertical furnace and thermally decomposed in an air atmosphere at a programmed heating rate of 20°C min^?1. The thermogravimetric study of the plasticized poly(vinyl chloride) demonstrated that two distinct weight loss fractions occurred during the decomposition process. Groups of four male swiss-webster mice were exposed to the thermal decomposition products of the first weight loss fraction in the range 0.03–0.77 mg l^?1 and to the second weight loss fraction in the range 0.03–0.38 mg l^?1. Dose-response curves were plotted by utilizing the maximum percent decrease in respiratory rate during each exposure as the response parameter. Comparison of these curves to a dose-response curve for hydrogen chloride showed that both the first and second weight loss fraction of plasticized poly(vinyl chloride) were more potent than hydrogen chloride in terms of sensory irritation. From these dose-response relationships qualitative and quantitative predictions of human responses to the thermal decomposition products of plasticized.     

A DSC investigation on the stabilizer distribution in PVC blends

The distribution of a liquid organotin stabilizer between the phases of heterogeneous poly(vinyl chloride) (PVC) blends has been studied by differential scanning calorimetry (DSC). This method can be used even at low stabilizer concentrations. At concentrations > 1 wt.-% the stabilizer can be detected in both phases of a PVC/SAN (poly(vinyl chloride)/poly(styrene-co-acrylonitrile)) blend. At lower concentrations no stabilizer could be found in the SAN phase. Determination of the induction period of thermal degradation at 180°C under nitrogen atmosphere showed no loss of thermal stability for blends containing the stabilizer partly in the SAN phase. Kinetic measurements with the DSC indicate a migration of the stabilizer out of the SAN phase, PVC/PMA (poly(vinyl chloride)/poly(methyl acrylate)) blends showed no solubility of the stabilizer in the soft PMA phase.     

Thermal stability of modified poly(vinyl chloride) by TGA

The stability of poly(vinyl chloride), as measured by thermogravimetric analysis, is significantly different from that of other thermoplastics. It is shown that the onset of weight loss can be correlated with the development of color in a processed resin. It is further shown that the ingredients within a rigid polyvinyl chloride compound drastically alter its thermal behavior. The effect of lubricant and stabilizer on the degradation of poly(vinyl chloride) is stressed.     

Detection of polymer transitions by measurement of thermal properties

Thermal diffusivity, thermal conductivity, and specific heat per unit volume were measured for the following polymers: poly(ethylene terephthalate), polytetrafluoroethylene, polycarbonate, polypropylene, and three poly(vinyl chloride) samples plasticized to different levels. First- and second-order transitions can be identified and located by the following features in the thermal property-temperature curves: discontinuities, sharp inflections, broad inflections, sharp maxima, broad maxima, and change in linear slope. The results for poly(vinyl chloride) indicate the possibility of the use of plasticizer to control the thermal insulation properties of polymers, both for steady-state and unsteady-state conduction.     

Head to head polymers

Pure head to head (H–H) addition polymers, such as H–H polyolefins, H–H acrylates and H–H poly(vinyl halides), have been of interest for the understanding of the structure/properties relationship of addition polymers. These polymer structures have provided challenges of synthesis, characterization and of the measurements of their mechanical and rheological properties. H–H polymers have never been prepared by direct synthesis and indirect polymerization techniques have to be used. Some of the H–H polymers, the polyolefins, were made by polymerization of properly substituted dienes followed by hydrogenation. The H–H polyacrylates were synthesized by copolymerization followed by polymer reactions and the poly(vinyl halides), by halogenation of poly(1,4-butadiene). Improved halogenation techniques for poly(1,4-butadiene) have made H–H poly(vinyl chloride) and H–H poly(vinyl bromide) accessible in larger quantities and have allowed an extensive characterization of these polymers.

Blends of H–H with H–T polymers as well as H–H polymers with other polymers were studied. H–H Poly(vinyl chloride) or poly(vinyl bromide) blends with polycaprolactone and poly(methyl methacrylate) were also investigated. The thermal behavior and the thermal degradation behavior of these blends were investigated. The most striking result of these investigations was that H–H and H–T poly(vinyl chloride) are immiscible as is H–H and H–T polyisobutylene over almost the entire range of compositions.     

聚氯乙烯/丁腈胶粉共混型热塑性弹性体

将聚氯乙烯与废丁腈胶粉经高温机械共混，制备了动态交联的共混型热塑性弹性体。讨论了共混比，硫化体系及其用量，废胶粉品种（丁腈胶粉，轮胎胶粉）等因素对热塑性弹性体性能的影响，同时将聚氯乙烯／丁腈胶粉与聚氯乙烯／轮胎胶粉制备的共混型热塑性弹性体的性能进行了比较。结果表明，以聚氯乙烯100份（质量份，下同），邻苯二甲酸二辛酯50份，丁腈胶粉80份，丁腈橡胶20份，过氧化二异丙苯0．5份，氧化锌5份及适量其他助剂可制得综合性能较好的共混型热塑性弹性体。扫描电镜结果显示该共混型热塑性弹性体具有较好的相容性。     

Thermal Decomposition of Polymer Mixtures Containing Poly(vinyl chloride)

Thermal decomposition of a series of 1 : 1 mixtures of typical polymer waste materials [polyethylene (PE), poly(propylene) (PP), polystyrene (PS), polyacrylonitrile (PAN), polyisoprene, poly(methyl methacrylate) (PMMA), polyamide‐6 (PA‐6), polyamide‐12 (PA‐12), polyamide‐6,6 (PA‐6,6), and poly(1,4‐phenylene terephthalamide) (Kevlar)] with poly(vinyl chloride) (PVC) was examined using thermal analysis and analytical pyrolysis techniques. It was found that the presence of polyamides and PAN promotes the dehydrochlorination of PVC, but PVC has no effect on the main decomposition temperature of polyamides. The hydrogen chloride evolution from PVC is not altered when other vinyl polymers or polyolefins are present. The thermal degradation of PAN is retarded significantly, whereas that of the other vinyl polymers is shifted to a slightly higher temperature in the presence of PVC. Among the pyrolysis products of PAN‐PVC mixture methyl chloride was found in comparable amount to the other gaseous products at 500°C pyrolysis temperature.     

Heterogeneous nucleating agents for crystallization of vinylidence chloride–vinyl chloride copolymers

Nineteen compounds are described that are effective heterogeneous nucleating agents for the crystallization of poly(vinylidene chloride–vinyl chloride) copolymers containing 7–13% vinyl chloride. Most of the compounds are relatively high-melting organic nitrogen heterocyclics. The more effective ones raise the polymer freezing points about 20–40°C using a prescribed thermal history.     

The thermal conductivity of nickel and copper dispersed in poly(vinyl chloride)

The thermal conductivity of segregated distributions of poly (vinyl chloride)/nickel (PVC/Ni) and poly(vinyl chloride)/copper (PVC/Cu) was measured for volume fractions ranging from 0 to 0.15. The thermal conductivities increased from 0.15 Btu/hr ft °F for unmodified PVC to 2.79 Btu/hr ft °F for PVC/15 percent Cu. While the thermal conductivity increased smoothly with volume loading, the electrical resistivity decreased discontinuously over fifteen orders of magnitude. Using the parallel slab model as a basis, a semi-empirical model was deduced which described the thermal conductivity as a function of volume loading. With this work, a survey of the thermal, electrical, and mechanical properties of segregated PVC composites is complete.     

The in situ polymerization of vinyl chloride in poly(butyl acrylate)

The in situ polymerization of vinyl chloride with poly(butyl acrylate) has been studied. Vinyl chloride was polymerized using a peroxydicarbonate initiator in sealed ampoules in the presence of various weights of poly(butyl acrylate). The products were examined by dynamic mechanical analysis and electron microscopy. It was found that if about 50% or less vinyl chloride was present in the mixture homogeneous blends were formed. If more than 50% vinyl chloride was present the polymerization passed through a two phase region in the three component phase diagram and inhomogeneous blends were formed. If homogeneous blends prepared as above were reswollen with vinyl chloride and the latter polymerized, then homogeneous blends containing more poly(vinyl chloride) could be prepared, avoiding the two phase region. The interaction parameters between vinyl chloride and both poly(vinyl chloride) and poly(butyl acrylate) were estimated using inverse gas chromatography. Using these and an estimate of the polymer/polymer interaction parameter the three component phase diagram could be qualitatively explained.     

氯乙烯—甲基丙烯酸环氧丙酯共聚树脂的合成及其性能

采用甲基丙烯酸环氧丙酯（EAMA）与氯乙烯（VC）共聚以改进聚氯乙烯的加工性能。研究表明，少量EAMA与VC共聚，使聚合速率大为降低；共聚树脂的分子量随转化率增加而增大，随共聚组成中EAMA含量增加而逐渐减小；共取和树脂的热稳定性和加工性能随EAMA含量增加而提高。     

Poly(vinyl chloride), Part II: Effect of polymerization temperature and molecular weight on the glass transition and melting point of poly(vinyl chloride)

A detailed study was made of the thermal behavior of poly(vinyl chloride) (PVC) homopolymers, whose chain length and structure were independently manipulated. Normal PVC polymerizations are made at temperatures, the selection of which determines the polymer chain length. In the case of PVC, this choice of temperature also determines its syndiotacticity, and so, its glass transition temperature, and in many ways, its processibility. The ability to understand how to control chain structure and length in PVC is critical in designing polymers for selected specific end use conditions. The thermal spectrum is known to be one measure of how polymers will perform. This study reveals how such controlled chain length/structure PVCs are characterized by thermal methods, and how one can separate individually the effects of syndiotacticity and molecular weight on thermal properties of poly(vinyl chloride).