Blends characterization

Reactive compatibilization of engineering thermoplastic PET with PP through functionalization has been reported by Xanthos et al. [57]. Acrylic acid modified PP was used for compatibilization. Additives such as magnesium acetate and p-toluene sulfonic acid were evaluated as the catalyst for the potential interchange or esterification reaction that could occur in the melt. The blend characterization through scanning electron microscopy, IR spectroscopy, differential scanning calorimetry, and... 

Table I. Chromatographic Methods for Copolymer/Blend Characterization...

Park, T. G. Cohen, S. Langer, R., Poly (l-lactic acid)/Pluronic blends Characterization of phase separation behavior, degradation, and morphology and use as protein-releasing matrices. Macromolecules 1992, 25, 116-122... 

Transport properties of ionomer blends, characterized by a given type of spheroids and the aspect ratio, e/a, can now be analyzed by the effective medium theory discussed in the previous section. In this theory, the two phases are assumed randomly mixed and the probability of finding each phase is equal to its volume fraction f.. The effective conductivity, o, of the composite for either Na+ of OH ions is given by (15) ... 

The first reactor-type thermoplastic polyolefin (R-TPO) was LLDPE/PP [Yamazaki and Eujimaki, 1970, 1972]. The three-component R-TPO s (PE with PP and EPR) soon followed [Strametz et al, 1975]. PE was also polymerized in the presence of active catalyst and an olefinic copolymer [Morita and Kashiwa, 1981]. Blending amorphous co-polyolefins with crystalline PO s (HDPE, LLDPE, PP), and a filler resulted in moldable blends, characterized by excellent sets of properties [Davis and Valaitis, 1993, 1994]. Blends of polycycloolefin (PCO) with a block copolymer (both polymerized in metallocene catalyzed process) and PE, were reported to show outstanding properties, viz. strength, modulus, heat resistance and toughness [Epple and Brekner, 1994]. 

Austroads. 2013. Maximising the Re-Use of Reclaimed Asphalt Pavement Binder Blend Characterization. AP-T245-13. Sydney, Australia Austroads. 

Buriti oil (BO) was mixed with PST or PMMA and the ensuing blends characterized in terms of absorption and photoluminescence properties associated with the specific structure of this oil extracted from an Amazonian palm tree [ 106]. Liu et al. reported very recently that SOYO can be homo-polymerized in CO2 supercritical conditions by cationic initiation with BFE without using a co-monomer [107]. 

Xie and Yang (2004) have prepared blends of PA-6 (70 parts) and PA-12,12 (30 parts) through additirm of SEBS-g-MA (15 wt%) which may serve as a coupling agent between the two PA. Blend characterization included SEM. 

Gui et al. (2013) prepared blends of an elastomeric PA with PPS in the presence of an epoxy resin. Blend characterization techniques included rheology, FTIR, and mechanical properties. 

CompatibUized blends of PBT with EVAc have been prepared through addition of 2,2 -(l,3-phenylene)-bis(2-oxazoline) coupling agent (Scaffaro and La Mantia 2006 Scaffaro et al. 2004). The effect of EAA addition was studied. Evidence was presented that chain extension of the reactive polymers by the coupling agent was negligible. Blends characterization included mechanical properties and morphology in comparison to uncompatibihzed blends. 

Larocca et al. (2010) prepared blends of PBT and SAN in the presence of MMA-co-EA-co-GMA. Blend characterization techniques included morphology. PBT samples with different molecular weight were used to change the PBT/SAN viscosity ratio. In related work, AES was used in place of SAN (Larocca et al. 2005). 

Li et al. (2012c) prepared blends of poly (lactic acid) with PP in the presence of radical initiator. Blend characterization techniques included DSC. The effects of different radical initiators and different concentrations of RI were studied. 

Zhang and He (2002) have compatibilized LCP polyester (Hoechst Vectra B950) with polysulfone-g-MA, the functionalized polysulfone having been prepared in solution. Blend characterization techniques included XPS, DMA, morphology and melt viscosity. 

Erick et al. (2013) prepared compatibilized blends of PEEK and PTEE (component ratios 0-100 to 100-0) using melt-processable PTEE treated by electron beam radiation to introduce -COE and -COOH functional groups by chain scission. Blend characterization techniques included mechanical properties and morphology. 

Dalai and Wenxiu (2002b, c) have reported blends of either HDPE or LDPE with EVAc effected by radiatimi cross-linking. Blend characterization techniques included morphology and thermal properties. 

Horiuchi and Ishii (2000) prepared PPS blends with LDPE-g-MA and PE-f-GMA in a TSE. Blend characterization techniques included morphology, TEM, EELS, DSC, tribological tests, and mechanical properties. 

Qureshi (2009) prepared PP/TPU blends compatibilized using an amine-functionalized PP, which functionalized PP had been prepared in a separate step by extrusion of PP-g-MA with either hexamethylenediamine or dodecamethyl-enediamine. Blends characterization techniques included SEM, rheology, and mechanical properties. 

Nano- and microporous structures obtained by gas foaming of nanostructured polymer blends characterization and evidences of the foaming mechanisms... 

In recent years, blend characterization by quantitative means has become particularly popular. Quantitative approaches require a calibration model to capture the concentration variation during the blending process. A quantitative model is able to express blending processes in terms of concentration variation, which is comparable to the standard criteria of current regulatory requirements. 

Another useful way of blend characterization is low voltage scanning electron microscopy. Even small composition changes can be observed by this method, which also allows the estimation of interphase interactions. 

Thermodynamic Aspects Parameters Used for Polymer Blend Characterization 1331... 

The effect of tacticity (i.e., the stereochemical arrangement of the units in the main chain of a polymer) on the properties of polymers and polymer blends has long been recognized with such basic differences as in the Tg, miscibility, crystallization, and blend characterization, including their mesoscale morphologies. In general, isotactic polymers (where all substituents are located on the same side of the polymer backbone) are semicrystalline in nature, whereas atactic polymers (where all substituents are placed randomly along the backbone) are amorphous. 

Block copolymers represent a special class of polymer blends characterized by covalent bonding between the individual molecules comprising the blocks. The molecular structure (monodisperse molecular weights) achieved with anionic polymerization has allowed for styrene-diene and diene-diene AB and ABA block copolymers, offering well-defined morphologies. The phase separation morphology and properties of block copolymers have been well-covered in many references [656-660] and wiU not be detailed here. Blends of block copolymers with their homopolymer constituents as well as in other polymer blends will be discussed. Cases where minor amounts of block copolymers are included in polymer blends as compatibihzers have been noted in Section 3.7. 

One of the earlier blend characterization studies employing SAXS investigated PVC/PCL blends [ 145]. The lamellar structure of crystalline PCL was volume filling up to 50% PVC. The analysis indicated that the amorphous phase was partially phase separated. Further studies using purified materials showed that PVC is incorporated between the PCL lamellae and the amorphous phase is homogeneous down to molecular dimensions [146]. More recent SAXS studies of PVC/PCL blends investigated the effects of molecular weight of both components... 

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