A kind of high graft rate functionalized EPDM rubber and preparation method thereof

Abstract

The invention discloses a high-grafting-ratio functionalization ethylene-propylene-diene monomer rubber and a preparing method thereof. The rubber is prepared in the mode that ethylene-propylene-diene monomer rubber and a multifunctional-group grafting monomer are reacted through thiol-alkene under high shear force at the high temperature. Particularly, the preparing method includes the steps that the multifunctional-group grafting monomer is synthesized through mercaptopropionic-acid pentaerythritol ester and carboxylic acid containing carbon-carbon double bonds or acid anhydride under existing of a radical initiator or a photoinitiator; the multifunctional-group grafting monomer and the ethylene-propylene-diene monomer rubber are melted in an internal mixer or a double-screw extrusion machine under the high shear force at the high temperature to prepare the high-grafting-ratio functionalization ethylene-propylene-diene monomer rubber. According to the high-grafting-ratio functionalization ethylene-propylene-diene monomer rubber and the preparing method thereof, the high-grafting-ratio functionalization ethylene-propylene-diene monomer rubber difficult to prepare with the normal melt grafting technology can be prepared, self polymerization and volatilization of the grafting monomer are avoided in the preparing process, environment protection can be achieved, and material performance is improved.

Description

technical field [0001] The invention relates to a method for grafting and modifying rubber, in particular to a high-grafting rate functionalized EPDM rubber and a preparation method thereof. Background technique [0002] Polymer blending is an important method to improve the properties of polymers, but because most polymers are thermodynamically incompatible, two-phase separation easily occurs when the two are blended, resulting in a serious decline in the properties of the blend. Adding a compatibilizer to increase the interfacial force between the two phases and reduce the size of the dispersed phase, thereby improving the performance of the blend, has become a common means of polymer blend modification. [0003] At present, the research on the alloying of polyolefin materials as toughening modifiers and other plastic materials has become one of the key areas, and the preparation of toughening agents has become one of the key technologies. Although ethylene propylene dien...

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Problems solved by technology

Although ethylene propylene diene monomer (EPDM, the same below) has high elasticity and excellent aging resistance, it has low polarity and poor compatibility with polar resins (such as PET, PBT, PA, etc.), so it is easy to blend After that, severe two-phase separation will occur, resulting in poor performance of the blend, so the EPDM rubber must be modified

[0007] The melt grafting method has become the main preparation method of functionalized EPDM rubber due to its reliable applicability, but there are several serious problems in this method that need to be solved urgently: 1) unsaturated carboxylic acid or anhydride is easily Volatile, the volatilized gas is irritating and harmful to the human body, which not only affects the environment, but also reduces the use efficiency of raw materials; 2) The free radical initiator will not only trigger the grafting reaction, but also trigger the EPDM rubber The increase in the amount of free radical initiators will increase the gel content of the graft, making the processing performance worse; 3) Although increasing the amount of free radical initiators can increase the grafting rate, in order to control the gel content, Usually the amount of free radical initiator is controlled at a low level, so it is difficult to prepare functionalized EPDM rubber with high grafting rate in the prior art

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