A chain extender masterbatch for PET extrusion foaming and its preparation method and application

Abstract

The present invention relates to a chain extender masterbatch for extrusion and foaming of PET and its preparation method and application. The masterbatch is mainly made of the following components by weight: 5-30 parts of PMDA, 25-90 parts of PBT , POE+POE‑g‑GMA 5~70 parts, wherein POE accounts for 0~85% by weight of POE+POE‑g‑GMA; the melting temperature of PBT is 170~225 °C; the preparation method is to combine the above groups Melt blending, the blending temperature is 180~230℃, the screw speed is 100~500rpm, air-cooled pelletizing or hot die surface pelletizing; the masterbatch can be used for fiber-grade PET, film-grade PET, bottle-grade PET, engineering Extrusion and foaming process of plastic grade PET and recycled PET; this application adopts PMDA as chain extender, adopts low melting point polyester PBT, polyolefin elastomer POE and POE‑g‑GMA compound as chain extender carrier, significantly improved The chain extension efficiency and foaming product performance of the masterbatch, and the preparation method is simple and convenient, and the chain extender masterbatch has a wide range of applications.

Description

technical field [0001] The invention relates to the technical field of chain extenders, in particular to a chain extender masterbatch for extrusion and foaming of PET, a preparation method and application thereof. Background technique [0002] Polyethylene terephthalate (PET) foam material has excellent heat resistance, heat insulation, water vapor barrier and mechanical properties, low density, recyclable, good environmental performance, and is used in many fields. The market prospect is broad, and PET extrusion foam molding can realize continuous production, which meets the requirements of industrial production. [0003] During the PET extrusion foaming process, due to the low molecular weight of conventional PET, regular molecular chains, and low melt strength; in the cell growth stage of PET melt foaming, the cell walls cannot withstand severe tensile stress and are prone to It leads to the rupture of the cell wall and the merging of cells; therefore, in the extrusion f...

AI Technical Summary

Problems solved by technology

In the early days, the chain extender masterbatch used in PET extrusion foaming process usually selects a single polymer as the carrier of the chain extender: 1) PCT International Publication No. WO 95 / 09884 discloses the selection of polyolefin as the polymer carrier , such as PP, PE and their copolymers, etc. However, at the temperature of PET extrusion processing, PP, PE and other polyolefins will undergo obvious thermal degradation, and the compatibility of PP, PE and PET is not good, which affects the final The performance of the product and the stability of the foaming process; 2) European Patent No. EP 2048188 disclosed that when ethylene-acrylic acid ester-glycidyl methacrylate copolymer was used as the polymer carrier, the prepared chain extender masterbatch The softening point is very low, usually lower than 100°C. During the extrusion and foaming process, the chain extender masterbatch will soften when it contacts with dry PET (drying temperature is usually > 160°C), which will affect the flow of materials in the extruder. Stability of transportation; moreover, under the temperature condition of PET extrusion and foaming, the viscosity of ethylene-acrylate-glycidyl methacrylate copolymer carrier is very low, which causes the pressure of the reaction system to drop, which is not conducive to PET foaming; 3 ) U.S. Patent No. US 2006 / 0293416 discloses that when low-melting point polyester is used as a polymer carrier, such as PCL, it will also face the problems of degradation of the polymer carrier and low viscosity at the foaming temperature, such as amorphous PETG, then Will reduce the crystallinity of the final product, thereby reducing the mechanical properties of the final product

[0005] In recent years, researchers have begun to use two-component polymer carriers, one of which is usually a high-melting polyester such as PET, and the other is a low-melting polymer, as disclosed in European Patent No. EP 2009043 Polyolefin is used as the low melting point component, U.S. Patent No. US 2011130475 discloses the use of ethylene-acrylate copolymer as the low melting point component, and Chinese Patent No. CN 102056967 discloses polyester elastomer TPEE as the low melting point component; However, during the preparation process of the chain extender masterbatch, the high melting point polyester component is easy to react with the chain extender, which affects the chain extension efficiency in the foaming process, so the high melting point polyester component needs to be ground into powder, Then the chain extender masterbatch is prepared at the processing temperature of the low melting point component, which undoubtedly increases the complexity of the processing process

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