EPR graft copolymers

VC/EPR Graft Copolymers. For most practical applications, compositions with low EPR content should be used. Specimens of this type may be obtained by dilution with PVC of a VC/EPR graft copolymer with high EPR content, or directly from a VC/EPR graft copolymer with low EPR content. 

Opacity. Specimens prepared from the VC/EPR graft copolymers are opaque. This seems to be because of the two-phase structure of the system, the large difference between the refractive indexes of the two phases, and the fact that the elastomer domains are large enough. 

VC/EPR Graft Copolymers. Possible applications of the VC/EPR graft copolymers all concern high-impact PVC extrusion of pipes and profiles, calendering, and injection molding. 

Table IV. Polymerization of Vinyl Chloride in the Presence of EPR EPR Graft EPR Grafted Copolymer VC ...

Kaneko et al. have reported the preparation of EPR macromonomers, which is useful to synthesize PMMA-g-EPR graft copolymers [106]. Graft copolymers possessing a poly(methacrylate) backbone and EPR branches were successfully synthesized by the copolymerization of EPR macromonomers with MMA. Methacryloyl terminated EPR, which were EPR macromonomers, were prepared by the sequential end functionalization of EPRs with vinylidene end group via hydroalumination, oxidation, and esterification (Fig. 20). The ATRP method can be used for the copolymeriza-... 

Furthermore, by using the ATRP method with a tetrafunctional initiator, the star copolymers consisting of four PMMA-g-EPR graft copolymer arms were also synthesized (Fig. 22). These unique topologies of the obtained copolymers can be confirmed by GPC measurement and NMR analysis. From TEM observation, the morphologies of these graft and star copolymers were remarkably altered by changing EPR branch number and the structure of the... 

Fig. 23 TEM images of a PMMA-g-EPR graft copolymer (EPR content 8.6 wt%), b PMMA-g-EPR graft copolymer (EPR content 38.1 wt%), c four-arms (PMMA-g-EPR) star copolymer (EPR content 36.3 wt %)...

PMMA backbone, which can control the segmental dispersion of PMMA and EPR segments in the range from 1 nm to 100 nm (Fig. 23). Moreover, it was clearly demonstrated that the PMMA-g-EPR graft copolymer with 38.1 wt% of EPR content worked efficiently as a compatibilizer for an EPR/PMMA polymer blend (Fig. 24). DSC analysis revealed the effect of the EPR branch on the Tg value of the PMMA backbone and a little incorporation of an EPR branch caused a large deviation of the Tg value from the homo-PMMA. 

Fig. 24 TEM images of EPR/PMMA blend samples a before adding PMMA-g-EPR graft copolymer (EPR/PMMA = 5/5 wt ratio) and b after adding PMMA-g-EPR graft copolymer (EPR/PMMA-g-EPR/PMMA = 45/10/45 wt ratio)...

On the other hand, the PMMA-g-EPR graft copolymers using the FRP method with AIBN showed a different morphology and thermal property from those after using the ATRP method, leading to the fact that the ATRP method is preferable compared to FRP method for the purpose of preparing well-defined macromolecular structures. Poly(EPR) can also be prepared by the free radical polymerization with AIBN [107]. 

Fig. 9. Dependence of the energy contribution on the filler (filled rubbers) or hard phase (thermo elastoplastics) content. 1 — filled silicone rubber1221 Sil-51 (A), Sil-4600 ( ) multiblock copolymer polyarylate-PDMS (O) us) graft copolymer of PDMS and AN ( x) 128>. 2 — Butyl rubber with high abrasion furnace black125). 3 — Butyl rubber with medium thermal black 125). 4 — SBR-filled rubber 126). 5 — aerosil //j Si-filled silicon rubber138). 6 — EPR-filled rubber 129,130). 7 — plastisized PVC filled with aerosil131132). 8 — SBS block copolymers 134)...

Our own work in this field followed two lines preparation of graft copolymers with high backbone-polymer content, such as VC/EPR (50-50) graft copolymers and preparation of products with low backbone-polymer content, such as VC/EPR (95-5) graft copolymers. 

Craft Copolymers with Low Backbone-Polymer Content. The procedure for preparing this kind of graft copolymer is based on the dissolution of the backbone polymer in the monomer, dispersion of this solution in water, and polymerization by means of an organic peroxide. It applies only to soluble backbone polymers, such as most EPR s. As the handling of a too-viscous vinyl chloride/backbone polymer solution is impractical, this procedure is normally used for preparing end products of the type VC/backbone polymer (95-5) or (90-10). 

State of Dispersion of the EPR. Specimens obtained from a VC/ EPR (95-5) graft copolymer and from a PVC-EPR/95-5 mechanical mixture have been examined with an interferential microscope (Figures 19 and 20). 

In addition, borane-containing POs can be prepared by copolymerization of olefin with borane monomers or by hydroboration of polyolefins including unsaturated groups, such as olefin-divinylbenzene copolymer and olefin-diene copolymers. Many kinds of graft copolymers, such as poly-elhylene-gra/f-poly( vinyl alcohol), PE-g-PMMA, polypropylcnc-gra/f-poly-(maleicanhydride-co-styrene), polypropylene-gra/f-poly(methacrylic acid), polypropylene-gra/f-poly(vinyl alcohol), polypropylene-gra/f-polycaprolac-tone (PP-g-PCL), polypropylcnc-gra/f-poly(methyl methacrylate) (PP-g-PMMA), poly( ethylene-co-propylene)-gra/f-poly(methyl methacrylate) (EPR-g-PMMA), and poly(ethylene-co-propylene)-gra/f-poly(maleic anhydride-costyrene), have been synthesized by such a method resulting in controllable composition and molecular microstructures [63-66]. 

PE with EVAc, CPE, BR, etc., have been chemically foamed at T = 150-210°C 5 to 95 wt% of LDPE or LLDPE with EAA PE with either poly(ethylene-co-vinylcarboxylate) or an acrylate PP with an ionomer and EBA-GMA PP with an ionomer, EBA-GMA and EPDM PO with a core-shell graft copolymer MBS-type PP with acidified-PP, or a carboxylic acid-modified EPR, SMM-MA, and either EMMA-GMA or EVAc-GMA LLDPE, PMMA and SEBS, EPR, or ethylene-styrene block copolymer (ES)... 

Copolymer ethylene and tetrafluoroethylene Copolymer from ethylene and vinyl acetate Ethylene-vinyl acetate-acrylic acid graft copolymer Ethylene-vinyl acetate-carbon monoxide copolymer Copolymer from ethylene, vinyl acetate, and vinyl chloride Copolymer of ethylene and vinyl alcohol also EVOH Fluorinated EPR tetrafluoroethylene/hexa-fluoro propylene rubber Hexa-fluoro propylene-vinylidenefluoride copolymer... 

EPR random copolymers are inherently thermoplastic and rubbery in nature but to give them useful levels of strength, creep resistance, heat resistance, and solvent resistance, they are commonly blended, or block or graft copolymerized, with crystalline polyolefins, particularly polypropylene, which on cooling separate as crystalline domains and act as thermoplastic crosslinks and reinforcing fillers. ... 

As reported in the introduction, grafting of maleic anhydride (MAH) is widely reported [48-52]. The modified polymer can be used as starting materials for the preparation of graft copolymers. Such copolymers have been extensively used as interfacial agents in blends of two incompatible polymers [53-57]. For example, the presence of EPR-g-succinic anhydride (EPR-g-SA) in blends of EPR and polyamide 6 led to a large improvement in the mechanical properties and in the morphological appearance of the blend, mainly attributable to the formation of (EPR -SA)-g-PA6 copolymer molecules [56,58]. 

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