Polymer blend chloride

Polymer Blends. The miscibility of poly(ethylene oxide) with a number of other polymers has been studied, eg, with poly (methyl methacrylate) (18—23), poly(vinyl acetate) (24—27), polyvinylpyrroHdinone (28), nylon (29), poly(vinyl alcohol) (30), phenoxy resins (31), cellulose (32), cellulose ethers (33), poly(vinyl chloride) (34), poly(lactic acid) (35), poly(hydroxybutyrate) (36), poly(acryhc acid) (37), polypropylene (38), and polyethylene (39). 

Blends with PVC. Nitrile mbber may be blended with poly(vinyl chloride) (PVC) by the polymer producer by two different techniques (1) blending of NBR latex with PVC latex followed by co-coagulation and drying, or (2) physically mixing the soHd NBR and PVC powder in mixing equipment such as an internal mixer. NBR—PVC polymer blends are well known for the good ozone resistance that is imparted by the PVC. 

Agari, Y, Shimada, M., Ueda, A. and Nagai, S. (1996) Preparation, characterization and properties of gradient polymer blends discussion of poly(vinyl chloride)/poly (methyl methacrylate) blend films containing a wide compositional gradient phase. Macromol. Chem. Phys., 197, 2017-2033. 

In view of the utility of the aromatic polyesters and the demonstrated effectiveness of the aromatic polyphosphonates as flame retardants, the combination of these two polymers was chosen for this study. In addition, this system provided a composition in which both copolymers and polymer blends could be prepared with identical chemical compositions. The polyesters were prepared from resorcinol with an 80/20 m/m ratio of iso-phthaloyl and terephaloyl chlorides while the polyphosphonates were resorcinol phenylphosphonate polymers. Copolymerized phosphorus was incorporated by replacement of a portion of the acid chloride mixture with phenylphosphonic dichloride. 

Preparation of Polymer Blends. A series of polymer blends was prepared by co-solutioning predetermined amounts of the poly(m-phenylene)isophthalate/terephthalate (80/20) with poly (m-phenylene)phenyl phosphonate, in methylene chloride. The polymer blends were recovered by evaporating the solution to dryness and ground to 40 mesh with a Wiley Mill. The composition of these blends and their analyses are summarized in Table I. 

Examples of known phosphazene polymer blends are those in which phosphazenes with methylamino, trifluoroethoxy, phenoxy, or oligo-ethyleneoxy side groups form blends with poly(vinyl chloride), polystyrene, poly(methyl methacrylate), or polyethylene oxide).97 100 IPNs have been produced from [NP(OCH2CH2OCH2CH2OCH3)2] (MEEP) and poly(methyl methacrylate).101-103 In addition, a special type of IPN has been reported in which a water-soluble polyphosphazene such as MEEP forms an IPN with a silicate or titanate network generated by hydrolysis of tetraethoxysilane or tetraalkoxytitanane.104 These materials are polyphosphazene/ceramic composites, which have been described as suitable materials for the preparation of antistatic layers in the manufacture of photographic film. 

For unplasticized chlorinated PVC, unplasticized chlorinated polymer blends of vinyl chloride and mixtures of these copolymers with other polymer blends, the following starting materials can be used PVC (homopolymer) polymer blends of vinyl chloride, vinylidene chloride, trans-dichloroethylene, ethylene, propylene, butylene, maleic acid, fumaric acid, itaconic acid, acrylic acid, methacrylic acid as well as chlorine. 

Unplasticized PVC and polymer blends of vinyl chloride can be added to chlorinated polymers manufactured using the above starting materials. 

After having studied in our laboratory, polymer blends of amorphous polymers poly-c-caprolactone and poly (vinyl chloride) (1,2) (PCL/ PVC), blends with a crystalline component PCL/PVC (3,4), poly(2,6-dimethyl phenylene oxide) (PPO) with isotactic polystyrene (i-PS) (5) and atactic polystyrene (a-PS) with i-PS (6), we have now become involved in the study of a blend in which both polymers crystallize. The system chosen is the poly(1,4-butylene terephthalate)/poly(ethylene terephthalate) (PBT/PET) blend. The crystallization behavior of PBT has been studied extensively in our laboratory (7,8) this polymer has a... 

Poly-e-caprolactone designated as PCL-700 was supplied by J. V. Koleske of the Union Carbide Corp. This polymer has been used in several other blend studies (1-6). The polymers blended with PCL were poly (vinyl chloride) (PVC) and nitrocellulose (NC). The poly-... 

Organic peroxides are used to initiate free-radical polymerization of ethylene, butadiene, styrene, vinyl chloride, vinyl acetate, and methyl methacrylate. They are also used to cure unsaturated polyesters, occasionally to cross-link thermoplastics such as polyethylene and polyacrylates, and increasingly for grafting and compatibiliza-tion of polymer blends. A variety of organic peroxides offer useful reactivity over a temperature range from 0 to 130°C or more, for different polymers and different processes. 

In the case of vinyl chloride polymerisation in polyfbutyl acrylate) these materials are completely miscible but a two phase region exists within the phase diagram as shown in Fig. 4 Polymerisation from A to B produces a homogeneous blend whereas from E to F produces a two phase structure. Composition B can be reswollen to C with vinyl chloride which can then be polymerised to D to producea homogeneous blend. This route avoids the two phase region in the phase diagram and in principle all compositions of polymer blend can be prepared in a series of steps. 

What is necessary with a polymer blend in order to achieve the desired breadth of transition is partial miscibility. Complete immiscibility leads to two Tgs unshifted with respect to the Tgs of the components, and complete miscibility leads to the same relatively narrow transitions observed for homopolymers. Of course, with immiscible blends, it is possible to mix two or more polymers with relatively close Tgs and achieve broad damping transitions in that way. Hourston and Hughes (33) have reported broad transitions for polyether ester-polyvinyl chloride (PVC) blends where specific interactions occur between the ether oxygens and the chlorines in the PVC leading to partial miscibility. 

Some studies show that pyrolysis of certain polymer blends can be influenced by the migration of a small molecule or a small radical formed from one type of polymer and affecting the other type. For example, poly(methyl methacrylate) (PMMA) in blends with poly(vinyl chloride) (PVC) shows higher resistance to heat. The thermal decomposition of PVC generates HCI, which interacts with the PMMA forming anhydride units in the middle of PMMA chains, as shown below ... 

Polyesters also are used in various polymer blends such as polycarbonate/poly(butylene terephthalate), poly(butylene terephthalate/acrylonitrile-styrene-acrylic) blends, poly(vinyl chloride)/poly(ethylene terephthalate), etc. Pyrolysis results on poly(vinyl chloride)/ poly(ethylene terephthalate) have been reported [64] showing that the two components influence each other, chloroesters of terephthaiic and benzoic acids being found in the pyrolysate. 

In this study, we discussed the graded and miscible blend of polyvinyl chloride(PVC)/ polymethacrylate(polymethyl methacrylate(PMMA) or polyhexyl methacrylate(PHMA)) by a dissolution-diffusion method, and characterized graded structures of the blends by measuring FTIR spectra and Raman microscopic spectra, and thermal behaviors around the glass transition temperature(Tg) by DSC method, or by SEM-EDX observation. Finally, we measured several types of mechanical properties and thermal shock resistance of the graded polymer blends. 

Sophiea et al. published the first classical composition-temperature phase diagram, working with the semi-IPN net-polyurethane-mter-poly(vinyl chloride) [Sophiea et al., 1994b]. They found a lower critical solution temperature, LCST = 120°C below this temperature the system was one-phased, and above, two-phased. Such behavior is now known to be characteristic of most polymer blends (see Chapter 2). 

Many research groups have been working on radiation processing of polymer blends, to stabilize the phases and improve performance. The polymers that have been used in the radiolytic studies of blends include polyethylene (PE), polypropylene (PP), ethylene propylene rubber (EPR), polyvinyl chloride (PVC), polystyrene (PS), and polymethylmethacrylate (PMMA). 

The external effects of the environment on polymer blends are chemical in nature, and normally lead to degradation of the polymers. Chain scission, depolymerization and reactions on the side-chain substituents all contribute to overall deterioration of blend properties. These are described for blends containing polyvinyl chloride, polystyrene, acrylics and polyolefins mixed with a variety of other polymers. The general feamres of radiation damage and the detrimental effects of processing are reviewed. 

Figure 14.5. DSC thermograms for aged polymer blends (a) polyvinylchloride/poly isopropyl methacrylate, immiscible blend, aged at a temperature of 60°C, and (b) polyvinyl chloride/polymethylmethacrylate, miscible blend, aged at 80°C. Time of aging, t in hours, is shown alongside each curve. Broken lines represent the un-aged samples for comparison.

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