Poly amorphous polystyrene

We shall examine the range of stability of the ordered structures of copolymers containing an amorphous polystyrene, polybutadiene or poly(ethyl methacrylate) block and acrystallizable polyethylene oxide) (PEO) or poly(e-caprolactone) (PCL) crystallizable block and the factors that determine the existence and the geometrical parameters of such periodic structures. 

For our experimental studies on polymer crystallization we used low molecular weight (Mw) poly(ethylene oxide) (PEO), either as a homopolymer or attached to an amorphous polystyrene or hydrogenated polybutadiene block. These block copolymers are abbreviated by PS-PEO and PB, -PEO, respectively. PEO is a weU-investigated polymer [5,19,36,37]. Molecular details of all investigated polymers are given in Table 1. 

A well studied example is given by the poly(oxyethylene-Z locfc-styrene). In case of atactic sequences of polystyrene, only the poly(oxyethylene), POE, can crystallize. A typical morphology of the POE is shown in Fig. 5.55. Single crystals of the copolymer can be grown from a common solvent which keeps both components mobile up to the time of crystallization of the POE-component. Figure 7.53 illustrates a growth spiral out of poly(oxyethylene-fclocfe-styrene), grown at 293 K from a solution of ethylbenzene (AB diblock, 28 wt-% oxyethylene block with a molar mass of about 10,000 Da). The crystal is comparable to the lamellar crystals of Fig. 5.55, i.e., the poly(oxyethylene) crystals are chain-folded with about 2.5 nm amorphous polystyrene layers at the interfaces. 

Simple homopolymers are not the only polymeric materials capable of forming single crystals. Block copolymers of poly(ethylene oxide) crystallize in the presence of considerable weight fractions of amorphous polystyrene (see Figure 6.12) (52). In this case square-shaped crystals with some spirals are... 

Recently Hadziioannou et al. (106) prepared amorphous polystyrene with extrusion ratios up to 10, using a solid-state coextrusion technique. Their poly-... 

Note that major gains in heat-distortion temperature are obtained when using reinforcing agents with the crystalline polymers nylon 6/6, poly(butylene terephthalate), and polypropylene, but not with the amorphous polystyrene and polycarbonate. This is a... 

As with other rigid amorphous thermoplastic polymers such as PVC and polystyrene (see the next chapter) poly(methyl methacrylate) is somewhat brittle and, as with PVC and polystrene, efforts have been made to improve the toughness by molecular modification. Two main approaches have been used, both of which have achieved a measure of success. They are copolymerisation of methyl methacrylate with a second monomer and the blending of poly(methyl methacrylate) with a rubber. The latter approach may also involve some graft copolymerisation. 

Amorphous thermoplastics These are made from polymers which have a sufficiently irregular molecular structure to prevent them from crystallising in any way. Examples of such materials are polystyrene, poly methyl methacrylate and polyvinyl chloride. 

A.O. Pozdnyakov, B.L. Baskin, O.F. Pozdnyakov, Fullerene C60 diffusion in thin layers of amorphous polymers polystyrene and poly(amethylstyrene), Techical Physics Letters, vol. 

In a kinetic sense, the system is a better solvent than HFIP alone. We postulate that MeCl2 swells the amorphous regions of PET thereby providing HFIP with an easy access to the crystalline regions. This swelling action does not occur with HFIP alone, and the dissolution process takes much longer. At room temperature, amorphous PET is Instantaneously solubilized by this solvent system. PET that has been annealed for >24 hr at 220 C to yield maximum crystallinity dissolves in <4 hr at room temperature. PET annealed in this manner does not dissolve in pure HFIP after 14 days at room temperature. Poly(butylene terephthalate) and aliphatic polyamides are soluble in this solvent system. Polystyrene is also soluble, which permits conventional calibration and the use of the universal calibration approach. We have determined the Mark-Houwlnk relationships for PET and polystyrene in 70/30 MeCl2/HFIP to be... 

Amorphous polymers are characterized by the following properties They are transparent and very often soluble in common organic solvents at room temperature. The following amorphous polymers have gained industrial importance as thermoplastic materials polyfvinyl chloride), polystyrene, polyfmethyl methacrylate), ABS-polymers, polycarbonate, cycloolefine copolymers, polysulfone, poly( ether sulfone), polyfether imide). 

The separation of the crystalline and amorphous phases into their respective spectra has been carried out for a number of polymers including polyethylene terephthalateS6), polystyrene 57), poly(vinyl chloride)58), polyethylene 59,60) nylon61), polypropylene 62), and poly(vinylidene flouride)63). 

By definition, thermoplastics have limitations at elevated temperatures. It is in this particular property that fibrous glass can lead to remarkable improvements. However, a sharp division exists for reinforced thermoplastics. The various reinforced thermoplastics can be put in two groups relative to DTUL. These consist of amorphous and crystalline or semicrystalline polymers. The amorphous polymers such as styrene-acrylonitrile, polystyrene, polycarbonate, poly (vinyl chloride), and acrylo-nitrile-butadiene-styrene are generally limited to modest DTUL improvements, usually on the order of 20°F with 20% glass. However, crystalline polymers such as the nylons, linear polyethylene, polypropyl-... 

ABA ABS ABS-PC ABS-PVC ACM ACS AES AMMA AN APET APP ASA BR BS CA CAB CAP CN CP CPE CPET CPP CPVC CR CTA DAM DAP DMT ECTFE EEA EMA EMAA EMAC EMPP EnBA EP EPM ESI EVA(C) EVOH FEP HDI HDPE HIPS HMDI IPI LDPE LLDPE MBS Acrylonitrile-butadiene-acrylate Acrylonitrile-butadiene-styrene copolymer Acrylonitrile-butadiene-styrene-polycarbonate alloy Acrylonitrile-butadiene-styrene-poly(vinyl chloride) alloy Acrylic acid ester rubber Acrylonitrile-chlorinated pe-styrene Acrylonitrile-ethylene-propylene-styrene Acrylonitrile-methyl methacrylate Acrylonitrile Amorphous polyethylene terephthalate Atactic polypropylene Acrylic-styrene-acrylonitrile Butadiene rubber Butadiene styrene rubber Cellulose acetate Cellulose acetate-butyrate Cellulose acetate-propionate Cellulose nitrate Cellulose propionate Chlorinated polyethylene Crystalline polyethylene terephthalate Cast polypropylene Chlorinated polyvinyl chloride Chloroprene rubber Cellulose triacetate Diallyl maleate Diallyl phthalate Terephthalic acid, dimethyl ester Ethylene-chlorotrifluoroethylene copolymer Ethylene-ethyl acrylate Ethylene-methyl acrylate Ethylene methacrylic acid Ethylene-methyl acrylate copolymer Elastomer modified polypropylene Ethylene normal butyl acrylate Epoxy resin, also ethylene-propylene Ethylene-propylene rubber Ethylene-styrene copolymers Polyethylene-vinyl acetate Polyethylene-vinyl alcohol copolymers Fluorinated ethylene-propylene copolymers Hexamethylene diisocyanate High-density polyethylene High-impact polystyrene Diisocyanato dicyclohexylmethane Isophorone diisocyanate Low-density polyethylene Linear low-density polyethylene Methacrylate-butadiene-styrene... 

The mechanical properties of poly(methyl methacrylate), PMMA, have been studied for quite a long time and, in addition to its industrial interest, PMMA constitutes a kind of reference material. Indeed, among the amorphous linear polymers it represents an intermediate between the very brittle polystyrene and the tough bisphenol A polycarbonate considered in Sect. 4. Furthermore, as shown in [1] (Sect. 8.1), the molecular motions responsible for its large p transition are precisely identified, as well as the nature of the cooperativity that develops in the high temperature range of the p transition. 

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