Overview of the compatibilizer

An auxiliary agent that encourages the blending of two incompatible polymers to create a stable blend is referred to as a compatibilizer, sometimes known as a compatibilizer. It is a polymer compatibilization agent in this context.

In plastic modification, substances such as PE-g-ST, PP-g-ST, ABS-g-MAH, PE-g-MAH, PP-g-MAH, etc. are used to create blended materials with high performance.

Presently, maleic anhydride is often grafted onto improved compatibilizers. Maleic anhydride monomer has more polarity and a superior compatibilization impact when compared to other monomers.

By adding strong polar reactive groups, the maleic anhydride grafted compatibilizer increases the material's polarity and reactivity. It is a kind of dispersion accelerator, compatibilizer, and polymer interfacial coupling agent. It is mostly used as a halogen-free filler, to strengthen glass fiber, to toughen, to bind metal, to determine alloy compatibility, etc. It can significantly increase filler dispersion and composite material compatibility, increasing the mechanical strength of the latter.

A compatibilizer with maleic anhydride grafts can boost the compatibility of organic and inorganic fillers, raise product tensile and impact strength, achieve high filling, use less resin, improve processing rheology, and smoothen surfaces.

The compatibilizer's function

enhance the two polymers' compatibility, enhance their adherence to one another, create a stable structure, and uniformize the scattered phase and continuous phase, or compatibilize, the two polymers. There are groups in the compatibilizer's molecule that can physically or chemically connect with the two polymers, which explains why it can compatibilize two polymers with dissimilar characteristics.

compatibilizer effectiveness

The so-called compatibilizer, which is introduced to the incompatible polymer system and in a certain way, may be thought of as a surfactant in terms of thermodynamics. However, the compatibilizer utilized in the polymer alloy system typically has a larger molecular weight. The compatibilizer will be confined on the interface between the two polymers after mixing and kneading at a high temperature, which will lower interfacial tension, thicken the interfacial layer, and decrease the size of dispersed particles. As a result, the system will eventually form a macroscopically uniform Thermodynamically stable phase structure that is characterized by microscopic phase separation.

Compatibilizers are categorized

The proper selection and use of the compatibilizer is essential to the implementation of the polymer alloy technology because it has a significant impact on the mixing and stability of the polymer alloy system. The compatibilizer may be split into two groups, namely non-reactive compatibilizer and reactive compatibilizer, based on the interactions between its matrix polymers.

compatibilizer without reaction

At the moment, non-reactive compatibilizers are more prevalent. The most popular technique in polymer alloy technology is the addition of a non-reactive compatibilizer to a system of incompatible polymers. Copolymers, which might be block copolymers, graft copolymers, or random copolymers, are typically used as non-reactive compatibilizers.

dynamic compatibilizer

Reactive compatibilizer is a polymer made up of active groups (mainly random hydroxyl and epoxy groups) and non-polar polymer main chain Pc. It can contribute to good compatibility because its non-polar polymer body can be compatible with the non-polar polymer in the blend and because the polar group can link or react with the active group of the polar polymer in the blend.

It is typically macromolecular and can have an active functional group on the side chain or at the end of the molecule. In diverse situations, the macromolecule's main chain should have high compatibility with at least one polymer matrix in the blend system. The macromolecule's main chain can be the same as or different from at least one polymer matrix in the blend system.

Differentiation and classification of compatibilizer

Anhydride type with a ring mounting(MAH)

The most popular kind of reactive compatibilizers right now are those of the cyclic anhydride type. The most common of them is a maleic anhydride compatibilizer that is grafted on polyolefin; its grafting rate ranges from 0.8% to 1.0%, and it is mostly used to modify polyolefin polymers. It is a binary or multi-component copolymerization compatibilizer that grafts maleic anhydride to PS or utilizes PS as the matrix and may be used with various modifications, blends, or alloys, such as PA/PC, ABS/GF, PA/ABS, PP/PA6, PP/PA66, etc. The usual dose is between 5% and 8%.

However, these compatibilizers can readily lead to excessive crosslinking and blend component deterioration, making it impossible to manage the reaction. They can also lower the thermal distortion temperature of plastic alloys.

Type of carboxylic acid

The acrylic type compatibilizer stands in for carboxylic acids as a product. The usage of acrylic acid is similar to that of maleic anhydride and often involves grafting it onto polyolefin resin.

epoxy kind

By grafting and copolymerizing epoxy resins or compounds with epoxy groups and other polymers, epoxy reactive compatibilizers are created. This kind of response might be beneficial for compatibility.

Type Oxazoline

With a grafting rate of 1%, PS grafted with oxazoline, also known as RPS, is a pretty significant compatibilizer. It is distinguished by a broad variety of uses and has the ability to generate graft copolymers through reactions with carbonyl, anhydride, and epoxy groups in addition to conventional amino or carboxyl-containing polymers. In PS, other technical plastics, or modified polyolefin resins, it can thus be employed. Additionally, it can be "in situ" compatibilized for immediate application in alloying, blending, and plastic modification.

imide kind

The imide type of polyacrylate, which has undergone modification, is mostly appropriate for engineering plastic alloys or blends like PA/PO, PC/PO, and PA/PC.

Type of isocyanate

M-isopropenyl-2,2-dimethylbenzoyl isocyanate is one of its ingredients. It may be applied to engineering polymeric alloys that have carboxyl and amino groups.

minimal mol weight

Low-molecular-weight compatibilizers are reactive compounds that react with other compounds to form organic and inorganic compounds of plastic alloys. They are based on reactive monomers and low-molecular-weight polymers. Some of these compounds can be compatible with one component of the plastic synthesis process. In this method, not only is the production of plastic alloy made simpler, but the cost of the raw materials is also kept cheap. The utilization of a mixing extruder is a crucial component in the manufacturing of low molecular compatibilizers, despite the comparatively high extruder requirements.