Internal mixer characterization

Mascia and Hashim [1997] have prepared compatibilized blends of PA with PVDF by using car-boxyhc acid-functionalized PVDF. In an example 20 parts PA-6 was combined with 80 parts PVDF-g-MAA (10% MAA) in an internal mixer at 240°C. The graft copolymer-containing blend was characterized by SEM, FTIR, mechanical properties, selective solvent extraction, and rheology. The effects of adding zinc acetate were studied. 

Favis [1994] and Willis andFavis [1988] prepared compatibilized PA blends with PP and carboxylic acid-functionalized EMAA ionomer. Blends containing 90-10 parts PA-6, 0-30 parts EMAA ionomer, and 10-90 parts PP were combined in an internal mixer at 250°C and characterized by torque rheometry and SEM. Dispersed phase particle size vs. interfacial modifier concentration was determined. Emulsification curves were constructed. Effects of mixing protocol on blend properties were studied. Blends were also prepared containing HOPE in place of PP. 

Vainio et al. [1997, 1996a] have compatibilized PEST/PP blends by graft copolymer formation between acid-terminated polyester and oxazo-line-grafted PP. Specifically, 30 parts PBT was mixed with 0-70 parts PP and 0-70 parts PP-g-oxazoline in an internal mixer at 250°C or TSE at 240°C. Blends were characterized by SEM, torque rheometry, DMA, and DSC. Oxazoline-functionalized PP was prepared by grafting PP... 

Copolymer formation by displacement reaction Solid-state chlorination of PP may lead to low levels of chlorine incorporation along the PP chain with minimal PP molecular weight degradation. Coran and Patel [1983 b] have blended (internal mixer, T = 190°C) 50 parts chlorinated PP with 45 parts NBR containing 5 parts amine-terminated NBR. The blend was characterized by mechanical properties vs. the use of unfunctionalized PP. Compatibilization resulted from copolymer formation through displacement reaction of chloride by amine groups. The blend was prepared in the presence of a vulcanization agent (3.75% of dimethylol phenol + 0.5% of SnCl ) to cause concomitant dynamic vulcanization of the rubber phase. 

PPE is not miscible with SMA containing as much as 28% MA [Witteler, et al., 1993]. To compatibilize these two resins, Koning, et al. [1996, 1993b] have added a monoamine-terminated PS that can form a graft copolymer with SMA. Since the amine-terminated PS is miscible with PPE, compatibilized PPE-SMA blends are obtained. Specifically, 30 parts of unfunctionalized PPE was blended (internal mixer at 220°C, mini-SSE at 280°C, or TSE at 326°C) with 56 parts SMA (28% MA) and 14 parts amine-functionalized PS. The blend was characterized by TEM, SEM, mechanical and thermal properties, DMA, and GPC copolymer detection. The effect... 

Tjong and Meng [1997] have described PA/LCP polyester blends with improved properties through addition of anhydride-terminated PP-MA. A block copolymer may form between PA amine end-groups and anhydride-terminated PP (see Section 5.8.8). For example, 86 parts PA-6 was mixed in an internal mixer with 14 parts PP-MA at 220°C followed by injection molding with 5-40 parts LCP (Hoechst Vectra A950). The blends were characterized by torque rheometry, mechanical properties, DMA, and SEM. 

PA/PS blends have been compatibilized through block copolymer formation between amine-terminated PA and anhydride-terminated PS. Anhydride end-groups were introduced into PS through reaction of either anion-terminated PS or hydroxy-terminated PS with trimeUitic anhydride chloride. Park et al. [1992] blended 80 parts PA-6 with 10-16 parts PS and 4-10 parts anhydride-terminated PS in an internal mixer at 240°C. The blends were characterized by torque rheometry, SEM, selective solvent extraction, DSC, morphological stability to annealing, and lap shear adhesion. The effect... 

Copolymer formation by miscellaneous reactions Hourston et al. [1991] have prepared compositions of 60-0 parts PBT and 16-40 parts EPDM in the presence of 0-60 parts copolymer of PBT with maleate ester (3.5% maleate) using a TSE at 255°C. A compatibilizing copolymer resulted from the crosslinking reaction between maleate olefinic groups and EPDM olefinic groups. Blends were characterized by mechanical properties and TEM. Model studies were performed to understand the crosslinking process. Blends were also prepared using an internal mixer at 250°C. 

Kim and Choi [1996b] have compatibilized blends of Phenoxy resin with PMMA. Compati-bilizing crosslinked copolymer resulted from transreaction between Phenoxy pendent alcohol groups and pendent PMMA ester groups. Compositions of 100-0 parts Phenoxy resin and 0-100 parts PMMA were prepared in an internal mixer at 240°C. The blends were characterized by DSC, FTIR, mechanical properties, rheology, and DMA. 

A compatibilizing copolymer may be formed through reaction between carboxylic acid groups grafted onto a PO chain and acrylate epoxide groups grafted onto a PP chain. In an internal mixer Liu et al. [1993] have prepared compositions comprising 20 parts NBR-g-AA, 0-75 parts PP and 0-25 parts PP-g-GMA (0.8% GMA). The blends were characterized by torque rheometry, SEM, FTIR, and mechanical properties vs. use of unfunctionalized NBR and vs. different GMA levels. 

Dharmarajan et al. [1995] have prepared com-patibilized blends of PO/PP/styrene copolymer. Blends of 100-0 parts PP, 0-100 parts SMA, 0-15 parts EP-g-l° amine (0.3 mol % amine), and 0-5 parts PP-2° amine (0.4 wt% amine) were combined in an internal mixer at 220°C. Blends were characterized by FTIR, DMTA, TEM, rheology, mechanical properties, lap shear adhesion, and paint adhesion. Properties were compared for blends containing either of the two amine-functionalized polymers alone. 

TseUos et al. [1997] have compatibilized PO/styrene copolymer blends through crosslinked copolymer formation between PO alcohol groups and anhydride groups on styrene copolymer. Specifically, 50 parts EVAl (1.6-7.5% VAl) was mixed with 50 parts SMA (8.4-14.7 mol% MA) in an internal mixer at 200°C. The blends were characterized by torque rheometry, FTIR, DSC, TGA, selective solvent extraction, and mechanical properties as a function of mole ratio alcohol to anhydride. Blend properties were compared to those with EVAc in place of EVAl. 

Specifically, 70-30 parts poly(hydroxy-butyrate-co-hydroxyvalerate) (4 mol% valerate) or polyhydroxybutyrate was mixed with 30-70 parts PCL in an internal mixer at 100° or 160°C in the presence of 0-0.5 parts DCP or DBP radical initiator. Blends were characterized by SEM, mechanical properties, selective solvent extraction, and FTIR. 

Mascia and Bellahdeb [1994 a, b] have com-patibilized Phenoxy polyether resin with an acid-functionalized polyacrylate resin through crosshnk-ing. A base, capable of forming alkoxide from the polyether hydroxy groups, should be used. Thus, 75-25 parts Phenoxy resin and 25-75 parts E-tBA-AA terpolymer (orEMAA Na ionomer) were blended in an internal mixer or TSE at 180-200°C in the presence of 2 parts NaOEt. Blends were characterized by selective solvent extraction, SEM, DSC, and rheology. The resulting crosslinked copolymers were used to compatibUize PET -I- HDPE. 

Compatibilized blends of 77 parts EPDM-SOjZn salt and 9 parts S-co-4-vinylpyridine with 4 parts ZnSt plasticizer were prepared in an internal mixer at 200°C [Lundberg et al., 1988 Agarwal et al., 1987 Peiffer et al, 1986]. The blends were characterized by FTIR, DMA, melt viscosity, DSC, and SEM. Mechanical properties were compared to blends containing unfunctionalized PS or containing EPDM-SOjNa or Mg salts. A copolymer linked by ionomeric crosslinks may form associations between sulfonate anion and pyridine nitrogen mediated by Zn cation. 

The benzocyclobutene functionality can thermally form an intermediate that can function as the diene partner in a classical Diels-Alder ring-forming reaction with an olefin. When benzocyclobutene and olefin are located on two immiscible polymers, the reaction can in theory lead to copolymer formation. Dean (1993) has postulated that copolymer is formed when 50-15 parts benzocyclobutene-terminated polyarylate is mixed with olefin-containing EPDM in an internal mixer at 265 °C. Blends were characterized by mechanical properties and DMTA. 

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