Immiscible Polymer Blends Compatibilized through Noncovalent Forces: Construction of a “Quasi-Block/Graft Copolymer” by Interfacial Stereocomplex Crystallites

Abstract

Interfacial compatibilization is acknowledged to be the most effective approach to improve interfacial strength between the thermodynamically immiscible components of polymer blends. However, the compatibilizer, mainly achieved by graft or block copolymers, necessarily connected by covalent bonds, can rarely be satisfied presently. Herein, we propose a concept of “quasi-block/graft copolymer” to compatibilize the immiscible polyolefin elastomer (POE) and poly(styrene-acrylonitrile-glycidyl methacrylate) (SAG) blends. The quasi-block/graft copolymer was achieved by the stereocomplex crystals (SC) of poly-l-lactic acid (PLLA) and poly-d-lactic acid (PDLA) moieties that reactively grafted on the main chains of the components. By taking advantage of the interfacial compatibilization through noncovalent forces, the microphase morphology of the blend can be adjusted and the mechanical properties can be improved: firstly, the curvature of the phase interface decreases significantly, facilitating co-continuous morphology on account of the “rigid” interfacial layers; secondly, the tensile strength and modulus of the blend are obviously improved; thirdly, the original phase structure of the blend can be well maintained during long-term annealing due to the high melting point of the interfacial SC. This strategy of compatibilizing immiscible blends by using the hydrogen bonding force of the stereocomplex opens up an idea for interfacial compatibilization.

Super Toughened PLLA/PBAT Blends with Modified Phase Interface via Constructing Cocontinuous Structure with the Aid of Stereocomplex Crystallites Toward Preparation of a Fully Degradable Material

“…The SC interfacial layer was achieved by the PLLA and PDLA that were reactively grafted on the polyolefin elastomer (POE) and poly(styreneacrylonitrile-glycidyl methacrylate) (SAG), respectively, imparting high modulus and rigidity, resulting in improved toughness for POE/SAG blends. 22 As expected, a compatibilizer that decreases interfacial tension accompanied by the rigid interface constructed by SC crystallite enhanced the interfacial strength, which could make a co-continuous morphology in the PLLA/PBAT blend.…”

“…Recently, Li et al reported the PLLA/PBAT blends with significant impact strength, in situ compatibilized by poly­(styrene- co -glycidyl methacrylate)- graft -( d -lactide) (SG- g -PDLA), which formed a rigid interface through the formation of stereocomplex crystallites, inducing a stable co-continuous morphology. The SC interfacial layer was achieved by the PLLA and PDLA that were reactively grafted on the polyolefin elastomer (POE) and poly­(styrene-acrylonitrile-glycidyl methacrylate) (SAG), respectively, imparting high modulus and rigidity, resulting in improved toughness for POE/SAG blends . As expected, a compatibilizer that decreases interfacial tension accompanied by the rigid interface constructed by SC crystallite enhanced the interfacial strength, which could make a co-continuous morphology in the PLLA/PBAT blend.…”

A stable amphiphilic hybrid nanoparticle compatibilizer constructed from polyhedral oligomeric silsesquioxane (POSS) for immiscible thermoplastic polyurethane/methyl vinyl silicone elastomer (TPU/MVQ) blends

“…The compatibility of TPU/MVQ blends is very poor, and the addition of some compatibilizers is an effective way to solve this problem, which can also increase the interfacial adhesion and optimize the morphology of TPU/MVQ blends. [9][10][11][12][13][14][15] In early studies, the compatibilizers of TPU/MVQ blends mainly included some block copolymers, 16,17 graft copolymers [18][19][20][21] and homo-copolymers, 10 such as the polydimethylsiloxane-polybutadiene-polyurethane triblock copolymer (PU-PB-PDMS), 22 the homo-copolymer of ethylene and methyl acrylate (EMA), 10 and the polyurethane-polysiloxane copolymers (PU-co-PSi). 9 However, the molecular chains of these copolymer compatibilizers are prone to curling and folding, and then form micelles and migrate into one phase during the blending process.…”

Influence of hybrid filler on charge conduction and storage performance of polyvinyl chloride/nitrocellulose blend for hybrid electrolyte application

“…[1] Electrical properties of polymer blends were engineered by combining polymers with different electrical conductivities, dielectric constants, and charge carrier mobilities. [2,3] This allows for the creation of materials with desired electrical insulation, conductivity, or dielectric properties, suitable for a wide range of applications including electronics, sensors, and energy storage systems. [4] Polyvinyl chloride (PVC) is a versatile polymer that exhibits a range of electrical and thermal properties, making it suitable for various electrical and thermal applications.…”