Compatibilizing effect of transesterification product between components in bisphenol-A polycarbonate/poly(ethylene terephthalate) blend

The compatibilizing effect of a random copolymer, which is the transesterification product, on its corresponding blend system of bisphenol-A polycarbonate/poly(ethylene terephthalate) (PC/PET) has been studied using a Differential Scanning Calorimeter and a Phase Contrast Microscope. It was found that after a long time of transesterification between PET and PC (50/50, wt %), the obtained product, that is, TCET random copolymer, is miscible with individual homopolymers of PC and PET. The addition of the TCET copolymer into the immiscible PC/PET blend can make the glass transitions of the PC-rich phase and PET-rich phase approach each other, and eventually merge into a single glass transition when the content of TCET in the ternary mixture reaches 60 wt %. Meanwhile, the phase structure images showed that with the increasing content of the TCET copolymer in the ternary blends, the size of the phase domains decreases and the phase domains further diminish at 60 wt % TCET. All these results proved the compatibilizing effect of TCET copolymer on the PC/PET blends in their ternary mixture. The mechanism of the compatibilizing effect is directly related to the reduction of the interfacial tension between PC-rich and PET-rich phase domains in the presence of increasing amounts of TCET copolymer in the ternary blends. © 1999 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 37: 2960–2972, 1999     

Can random copolymers serve as effective polymeric compatibilizers?

We investigate the compatibilizing performance of a random copolymer in the melt state, using transmission electron microscopy. Blends of polystyrene (PS) and poly(methyl methacrylate) (PMMA) are chosen as a model system, and a random copolymer of styrene and methyl methacrylate (SMMA) with 70 wt % styrene is used as a compatibilizer. From TEM photographs it is clear that SMMA moves to the interface between PS and PMMA domains during melt mixing, and forms encapsulating layers. However, the characteristic size of the dispersed phase increases gradually with annealing time for all blend systems studied. This demonstrates that the encapsulating layer of SMMA does not provide stability against static coalescence, which calls into question the effectiveness of random copolymers as practical compatibilizers. We interpret the encapsulation by random copolymers in terms of a simple model for ternary polymer blends. © 1997 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 35: 2835–2842, 1997     

Effects of Compatibilizer and Airflow Field on the Formation of Helical Microfibers via Melt Blowing

We explore the approaches to improving the fabrication of melt‐blown helical microfibers, which have found the applications in sorption and filtration due to their unique morphology and excellent properties. To explore the effect of compatibilizer on the formation of helical microfiber, polypropylene (PP), polyurethane (TPU), and PP grafted with maleic anhydride (PP‐g‐MAH) are melt blown to fabricate microfibrous nonwovens. The results of rheological test and differential scanning calorimetry show that the addition of PP‐g‐MAH helps to increase the miscibility of the PP/TPU blends. Two die configurations are used to study the effect of airflow filed on the formation of helical microfibers. The computational fluid dynamics simulation results show that the modified swirl die intensifies the swirling strength of the melt blowing airflow. The addition of compatibilizer and modification of the airflow field both benefit the formation of helical microfibers from polymer blends. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2019 , 57, 1423–1433     

Reactive compatibilization of polyamide‐6 (PA 6)/polybutylene terephthalate (PBT) blends by a multifunctional epoxy resin

A multifunctional epoxy resin has been demonstrated to be an efficient reactive compatibilizer for the incompatible and immiscible blends of polyamide‐6 (PA 6) and polybutylene terephthalate (PBT). The torque measurements give indirect evidence that the reaction between PA and PBT with epoxy has an opportunity to produce an in situ formed copolymer, which can be as an effective compatibilizer to reduce and suppress the size of the disperse phase, and to greatly enhance mechanical properties of PA/PBT blends. The mechanical property improvement is more pronounced in the PA‐rich blends than that in the PBT‐rich blends. The fracture behavior of the blend with less than 0.3 phr compatibilizer is governed by a particle pullout mechanism, whereas shear yielding is dominant in the fracture behavior of the blend with more than 0.3 phr compatibilizer. As the melt and crystallization temperatures of the base polymers are so close, either PA or PBT can be regarded as a mutual nucleating agent to enhance the crystallization on the other component. The presence of compatibilizer and in situ formed copolymer in the compatibilized blends tends to interfere with the crystallization of the base polymers in various blends. © 2000 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 38: 23–33, 2000     

On the modification of the nitrile groups of acrylonitrile/butadiene/styrene into oxazoline in the melt

Oxazoline functionality is well known to be highly reactive toward a lot of other functional groups like carboxyls, hydroxyls, mercaptans, and amines. In this work we report the possibility to modify the nitrile groups of an acrylonitrile/butadiene/styrene (ABS) copolymer into oxazoline in the molten state in the presence of aminoethanol as modifier agent and zinc acetate as a catalyst. The reaction has been carried out in a batch mixer and in a corotating twin screw extruder. The conversion of the nitrile groups into oxazoline has been verified by infrared spectroscopy, NMR analysis microanalysis and confirmed by thermomechanical characterization. The results indicate that the kinetic of grafting is fast and the conversion of the nitrile groups into oxazoline relatively high, encouraging the use of this modified polymer in the reactive compatibilization of ABS‐based blends. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 1795–1802, 2000     

Synthesis of poly(ethylene‐co‐vinyl alcohol)‐g‐polystyrene graft copolymer and their applications for ordered porous film and compatibilizer

A series of new functional poly(ethylene‐co‐vinyl alcohol)‐g‐polystyrene graft copolymers (EVAL‐g‐PS) with controlled molecular weight (M_n = 38,000–94,000 g mol^?1) and molecular weight distribution (M_w/M_n = 2.31–3.49) were synthesized via a grafting from methodology. The molecular structure and component of EVAL‐g‐PS graft copolymers were confirmed by the analysis of their ¹H NMR spectra and GPC curves. The porous films of such copolymers were fabricated via a static breath‐figure (BF) process. The influencing factors on the morphology of such porous films, such as solvent, temperature, polymer concentration, and molecular weight of polymer were investigated. Ordered porous film and better regularity was fabricated through a static BF process using EVAL‐g‐PS solution in CHCl₃. Scanning electron microscopy observation reveals that the EVAL‐g‐PS graft copolymer is an efficient compatibilizer for the blend system of low‐density polyethylene/polystyrene. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 516–524     

Morphology and properties of polypropylene/ethylene–octene copolymer/clay nanocomposites with double compatibilizers

The influence of nanoclay on the morphology and properties of the polypropylene (PP)/ethylene–octene block copolymer (EOC) blend with double compatibilizers of maleated PP (PP‐g‐MA) and maleated EOC (EOC‐g‐MA) was investigated and compared with the nanocomposites containing either PP‐g‐MA or EOC‐g‐MA as a compatibilizer. X‐ray diffraction, transmission electron microscopy, and scanning electron microscopy were utilized for morphological characterization in conjunction with dynamic mechanical thermal analysis, mechanical testing, and rheological evaluation of these nanocomposites. The results suggested that in the nanocomposite including both compatibilizers of PP‐g‐MA and EOC‐g‐MA, clay was dispersed as a mixed structure of intercalation and exfoliation in both phases of the polymer blend. Comparing the mechanical properties of the studied nanocomposite with nanocomposites of PP/EOC/PP‐g‐MA/clay and PP/EOC/EOC‐g‐MA/clay also indicated that the nanocomposite containing mixed compatibilizers displayed higher tensile modulus, tensile strength, and complex viscosity because of the better dispersion of clay in both phases. The results also confirmed the increased structural stability and reduced dispersed phase size of PP/EOC/PP‐g‐MA/EOC‐g‐MA blend in the presence of clay that proposed the compatibilization role of clay in this nanocomposite. Copyright © 2014 John Wiley & Sons, Ltd.     

Effect of novel compatibilizers on the properties and morphology of PP/PC blends

A series of compatibilizers, including polypropylene (PP) grafted with 2‐tertbutyl‐6‐(3‐tertbutyl‐ 2‐hydroxy‐5‐methylbenzyl)‐4‐methylphenyl acrylic ester (BPA), glycidyl methacrylate (GMA), GMA/styrene (GMA‐st), and 2‐allyl bisphenol A (2A) were investigated for the purpose of improving the compatibility of PP/polycarbonate (PC) blends. PP‐g‐BPA shows a remarkable compatibilizing effect on PP/PC blends since it has similar group‐benzene ring with PC, and it is a sort of heat‐resistant antioxidant in the meantime, which can reduce the molecular degradation of PP during grafting and blending under high temperatures. Its compatibilizing effect was examined in terms of the mechanical, thermal properties, and morphologies. PP/PC blends show a decreasing and much more homogeneous size of dispersed PC particles through addition of a small amount of PP‐g‐BPA, and dynamic mechanical analysis (DMA) reveals a noticeable approach of T_g between PP and PC, indicating the improvement of the compatibility of PP/PC blends. Furthermore, styrene‐ethylene‐butylene‐styrene (SEBS) as a toughening rubber and a compatibilizer was applied to PP/PC blends. Around 25 wt% SEBS and 20 wt% PC lead to high toughness and strength of PP. Copyright © 2008 John Wiley & Sons, Ltd.     

Catalytic Polymerization of Methyl-phenyldisilazanes and Alkylphenyl-N-phenylaminosilanes

The reaction of polymerization of methylphenyldisilazanes and alkyl-phenyl-N-phenylaminosilanes under the action of alkalis at high temperature was studied. It was demonstrated that polymerization of the above compounds is accompanied by the evolution of benzene as a result of splitting off of phenyl groups from silicon atoms and of hydrogens from nitrogen atoms. When hydrogen atoms bound with nitrogen were exhausted, in the case of polymerization of symmetrical tetramethylphenyl-and dimethyl-tetraphenyldisilazanes, 1,1,3-trimethyl-1,3,3-triphenyldisilazane, and methyldiphenylphenylaminosilane, the reaction was kept going by the interaction of phenyls with the protons of the methyl groups. Polymers of a complex structure were obtained as a result.     

Synthesis and characterization of polyethylene‐g‐polystyrene as the compatibilizer for polypropylene/ Polystyrene blends

Polyethylene‐g‐polystyrene (PE‐g‐PS) was synthesized as a compatibilizer for polypropylene/polystyrene­(PP/PS) blends by the living radical polymerization of styrene with polyethylene‐co‐glycidylmethacrylate (PE‐co‐GMA). The compatibilizer effect of PE‐g‐PS on the morphology and thermal properties of PP/PS blends was investigated. The crystalline temperature of PP in PP/PS blends decreased with increasing PE‐g‐PS contents. Morphologies of PP/PE‐g‐PS/PS blends showed much better dispersion of each domain for higher PE‐g‐PS contents. The molecular weight of PS segment in PP/PE‐g‐PS/PS blend was increased by addition of styrene monomer during the post melt blending process where post living radical polymerization reaction proceeded. Copyright © 2003 John Wiley & Sons, Ltd.