Structure property relationships of chlorinated polyethylene

Oswald, H. J.; Kubu, E. T.

doi:10.1002/pen.760030304

Cited by 8 publications

(11 citation statements)

References 3 publications

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“…Furthermore, the height of this maxi mum does not vary with the molding time, which, for a temperature of 200°C, was 15 minutes. Analogous behavior was observed by Oswald and co-workers (12) for blends of chlorinated polyethylene with a high chlorine content when the difference between the TJs of the two components was greater than 30°C. In our case the values of ATg are about 45° (E13) and 34°C (E14) in regard to the homopolymer PVC.…”

Section: Figure 4 Dynamic-mechanical Properties Of Samples C7 and D7supporting

confidence: 59%

Blends of Chlorinated and Normal PVC

Ajroldi

Gatta

Gugelmetto

et al. 1971

Multicomponent Polymer Systems

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Poly(vinyl chloride) (PVC) was chlorinated with or withoutCHCls as swelling agent, to provide samples of CPVC for study. The following properties were determined: thermal stability (dehydrochlorination), Vicat softening point, dynamic modulus, impact strength at various temperatures, and creep at 80° and 100°C. All these properties depend on both chlorine content and type of chlorination process. At constant chlorine content the CPVC samples prepared in the presence of the swelling agent have higher thermal stability, higher Vicat softening point, lower impact strength, and lower creep deformation than the samples prepared without the swelling agent. The logarithm curves of dynamic modulus vs. temperature of the blends of PVC with CPVC of high chlorine content, exhibit a sharp flex at the glass transition temperature of PVC. Chlorination without a swelling agent results in a blend between the PVC and CPVC of various chlorine contents. Moreover PVC and CPVC with high chlorine content are incompatible. When mixed together, heterogeneous blends are obtained."pvuring the past few years many studies have been made to find an industrial way to obtain postchlorinated poly (vinyl chloride) (CPVC). The processes which, for simplicity and low cost, seem most promising are those in which PVC is chlorinated in the heterogeneous phase. These processes can be carried out either in the presence or ab sence of a liquid-dispersing phase and with the PVC either swollen by a solvent (swollen process or gel phase) (4,14) or in the unmodified powder state (unswollen process) (7, 21).

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Section: Figure 4 Dynamic-mechanical Properties Of Samples C7 and D7supporting

confidence: 59%

Blends of Chlorinated and Normal PVC

Ajroldi

Gatta

Gugelmetto

et al. 1971

Multicomponent Polymer Systems

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“…A crystallinity of 5-10% would correspond to a minimum sequence length of 6-7 monomer units. Juijn postulates incorporation of isotactic straight chains into the orthorombic crystals to account for the improbably short minimum sequence lengths of syndiotactic units.Some authors (18,45) estimate the minimum number to be 5 units, which is consistent with the poor order along the chain axis.…”

Section: Figmentioning

confidence: 59%

“…CPE can thus be considered as a terpolymer composed of ethylene, vinylchloride and 1,2 dichloroethylene segments (45). The presence of vinylidene units has also been suggested (46).…”

Section: Svanson and Elmqvist (34) Carried Out Wide Line Nmr Measuremmentioning

confidence: 99%

Phase structure of polyvinyl chloride (PVC) and PVC/polymer blends

Terselius¹,

Rånby²

1981

Pure and Applied Chemistry

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Commercial PVC is considered as a largely amorphous glassy polymer containing a small fraction of crystalline (ordered) structure. Based on the unique strength of plasticized PVC the presence of a three dimensional network of crystallites is generally accepted. The crystallites consist of a small number of syndiotactically ordered monomer units. The exact size, order and amount of crystallites in PVC is still an open question. The morphology of 'as polymerized" PVCis characterized by free-flowing grains (about lOO,um) containing aggregates of primary particles (about 1 ,um). The existence of subprimary particles are often claimed but the evidence is still controversial. A remaining microheterogeneity after plasticizing with diallylphtalate or ethylene-vinylacetate copolymer with 63 wt-% vinylacetate is, however, indicating the presence of unplasticized nodules or crystallites.The phase structure of PVC blends with acrylo-nitrile-butadiene rubber (NBR), ethylene-vinylacetate copolymer (EVA) and chlorinated polyethylene (CPE) have been elucidated with special reference to the formation of a network structure. The phase structure is shown to depend on compatibility, method of blending and processing temperature at mechanical blending. Thus at increasing compatibility i.e. by increasing the content of acrylonitrile, vinylacetate and chlorine in NBR, EVA and CPE, respectively, the phase inversion of PVC to rubber as continuous phase, is shifted from about 15 to about 2% content of rubber. Increasing the mechanical processing temperature from below to above the critical temperature of primary particle fusion shifts the phase inversion to higher rubber contents (about 30% for non-compatible rubber). At solution blending the inversion is shifted to still higher rubber contents (about 50%). The phase structure of blends with ABS-type of polymers are briefly reported and the possibility of network structure formation is discussed. Finally, blends with crystallizable polymers like polycaprolactone (PCL) and Hytrel (a thermoplastic poyester-ether rubber) are reviewed. The amorphous segments of these polymers are compatible with PVC. PHASE STRUCTURE OF PVCIntroduction PVC has been produced and processed in large volumes for a long time on account of its versatile properties in relation to its low price. Nevertheless, the polymer is still considered "difficult" and its basic properties to a large extent unexplored (1). These problems can be discussed in terms of structure on a molecular,intermolecular and supermolecular level.

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“…The value 226°C is indoubtedly below the real one because these authors 1 -CHCl-CHCl-CH"-CHCl-CH2-CHCl-CHCl-102…”

Section: Dynamic Tga Experimentsmentioning

confidence: 87%

Chlorinated Polyethylene. III. Relationships of Microstructure and Thermal Properties

Quenum

Berticat

Vallet

1975

Polym J

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ABSTRACT:The thermal properties (viz., second-order transitions, melting points, dynamic and isothermal heat behaviour) of chlorinated polyethylene (CPE) samples are studied here. Thermomechanical analysis (TMA), differential thermal analysis (DTA), and thermogravimetric analysis (TGA) results are listed together to correlate the thermal properties and the microstructure of CPE samples, of various chlorine contents by weight, produced from thermal chlorinated or photochlorinated linear and branched polyethylene samples. The dehydrochlorination rate of a CPE sample is shown to be strongly dependent on its microtacticity up to a 56-61-% chlorine content by weight value· Beyond this 56-61-%Cb interval the microtacticity influence is screened by the steric hindrance introduced by the err (-CHz-C!:!Cl-CCb-or -CHCl-C!:!Cl-CCb-), an -CHCl-C!:!Cl-CHCl-or -CHz-C!:!Cl-CHCl-), and [3n (-CHCl-C!:!z-CCb-) structures. At the saturation level (73-% Clz), the higher a CPE ratio, nb CHCllnb CHz, is, the lower is its maximum dehydrochlorination rate. When its ratio, nb 2 CHCllnb CHz, is less than 4, a saturated (73%) CPE sample has a unique global dehydrochlorination activation energy (Ea); when this ratio stands between 4 and 6, there are two global dehydrochlorination E.. The structures which could be regarded as responsible for these different global Ea and the second-order transitions are specified.KEY WORDS Chlorinated Polyethylene I Thermomechanical Analysis I Differential Thermal Analysis I Thermogravimetric Analysis I Second-Order Transitions I Maximum Dehydrochlorination Rate I Very few studies have been published about the thermal properties of CPE. The first one, made by Oswald and Kubu 1 dealt with glass-transition temperatures (Tg)· Era and Lindberg 2 showed the effect of heat treatment on crystallinity. Abu I sa 3 studied the dechlorination mechanism and the effect of added antimony oxide on the rate of dehydrochlorination. Saglio, et at., 4 studied the degradation of saturated (73 %) CPE and showed that fibers of saturated CPE can be used as a carbon fiber precursor.relate their microstructure and thermal properties in this paper.In carbon backbone high polymers secondary transitions can be detected besides the main second-order transition, i.e., the glass-transition temperature (T g), and the main first-order transition, i.e. the solid-liquid-transition or the melting temperature. They are:(1) The secondary second-order transitions occuring, generally, at temperatures less than Tg. They are related to the motion of short segments of the polymer's backbone (viz., branchings, substituants, "crankshaft" or "kink" mechanisms11'12) related to motions in the amorphous or crystalline phase.The CPE samples used for the above studies were, generally, commercial ones supplied without the specific conditions of their preparation which are required 5 to correlate microstructure and properties. In addition, their microstructural characterizations have been made only with infrared analysis, which is not sufficient.Since we have...

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Structure property relationships of chlorinated polyethylene

Cited by 8 publications

References 3 publications

Blends of Chlorinated and Normal PVC

Blends of Chlorinated and Normal PVC

Phase structure of polyvinyl chloride (PVC) and PVC/polymer blends

Chlorinated Polyethylene. III. Relationships of Microstructure and Thermal Properties

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