A method for preparing polypropylene low-temperature solid-phase foamed beads

A technology of foaming beads and polypropylene, which is applied in the field of polymers and can solve problems such as unsatisfactory crystal structure and inability to prepare polypropylene beads

Active Publication Date: 2017-09-26
SHANGHAI FUYUAN PLASTICS SCI CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, although this type of branched polypropylene has good foaming performance in preparing polypropylene extruded foam sheets, it cannot be directly used in the low-temperature solid-phase foaming method to prepare polypropylene beads, which is due to its The crystalline structure is not satisfactory due to the requirements for the preparation of polypropylene beads

Method used

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  • A method for preparing polypropylene low-temperature solid-phase foamed beads
  • A method for preparing polypropylene low-temperature solid-phase foamed beads
  • A method for preparing polypropylene low-temperature solid-phase foamed beads

Examples

Experimental program
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Effect test

Embodiment 1

[0054] Use the following twin-screw blending device: the screw diameter (D) of the extruder is Φ35mm, the length-to-diameter ratio (L / D) is 48, and a quenching device is installed outside the die, which can extrude The blend is immediately quenched at -50 to 10°C.

[0055] A foaming apparatus as follows was also used: an autoclave equipped with a foaming agent air-tight system, a metering pump, a pressure sensor, and a temperature controller, and a vulcanizer plate foaming template to prepare foamed beads.

[0056] In addition, branched polypropylene was used as follows: -1 , the melt tensile strain critical fracture value is 3.5, the relationship between tensile stress (σE) and tensile deformation (ξ) is dlnσE / dξ>1, and the melt flow rate is 2.5g / 10min. Based on 100 g of branched polypropylene, 0.5 g of antioxidant 1010 and 1 g of 1000-mesh talcum powder as a bubble nucleating agent were added. The above components are fully mixed in a high mixer, ready to use.

[0057]Add...

Embodiment 2

[0061] With cyclopentane as blowing agent, others are all identical with embodiment 1. The various characteristics of the obtained expanded beads are shown in Table 1. The prepared expanded beads are high-quality expanded beads with uniform cells, smooth surface and no wrinkles.

Embodiment 3

[0065] The saturation temperature during foaming is set to be 158° C., the foaming temperature is 154° C., and the others are the same as in Example 1. Various characteristics of the obtained expanded beads are shown in Table 1, and the prepared expanded beads are high-quality expanded beads with uniform cells, smooth surface and no wrinkles.

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Abstract

A method for preparing polypropylene low-temperature solid-phase foamed beads, comprising the steps of: A, using branched polypropylene, a bubble nucleating agent and an antioxidant as raw materials for melt blending into a polypropylene composition; B, melt mixing Immediately after the quenching treatment; C. The polypropylene composition after the quenching treatment is subjected to low-temperature solid-phase foaming with a foaming agent to obtain expanded polypropylene beads; At a tensile rate of ‑1, the critical fracture value of the tensile strain of the melt exceeds 1.5, and the relationship between the tensile stress σE and the tensile deformation ξ satisfies dlnσE / dξ>0.5. The method of the present invention can obtain polypropylene beads with an expansion ratio of 6 to 40 times. Various foamed molded products prepared from the foamed polypropylene beads have excellent mechanical properties and can be recycled, and can be widely used in the automotive industry, food processing industry, and packaging cushioning materials for electronic appliances.

Description

technical field [0001] The invention relates to polymers, in particular to a method for preparing polypropylene low-temperature solid-phase foamed beads. Background technique [0002] Polypropylene foam products mainly include polypropylene extruded foam sheets and various special-shaped parts obtained by molding polypropylene foam beads. Compared with the polystyrene, polyurethane and polyethylene foams commonly used at present, polypropylene foam has higher service temperature, excellent mechanical properties, high impact energy absorption capacity and excellent performance such as easy degradation and environmental protection. It is widely used in the fields of cushioning packaging, thermal insulation materials, auto parts and building insulation materials. However, since linear polypropylene is a semi-crystalline polymer, the viscous flow temperature is very close to the melting point, the melt strength is low after melting and there is no strain hardening behavior, res...

Claims

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Application Information

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Patent Type & AuthorityPatents(China)
IPC IPC(8): C08J9/18C08L23/12C08L23/26C08L51/06
Inventor郑安呐胡渠敦管涌危大福李书召胡福增
OwnerSHANGHAI FUYUAN PLASTICS SCI CO LTD