CPVC/PVC heat-resistant composite material and preparation method based on supercritical CO2 extrusion foaming

Abstract

The invention relates to a polyvinyl chloride composite, and specifically relates to a CPVC / PVC (Chlorinated Polyvinyl Chloride / Polyvinyl Chloride) heat-resistant composite extruded and foamed based on supercritical CO2 (Carbon Dioxide) and a preparation method of the CPVC / PVC heat-resistant composite. The CPVC / PVC heat-resistant composite comprises the following components in percentage by weight: 50-56% of chlorinated polyvinyl chloride resin, 30-35.3% of polyvinyl chloride resin, 0.25-1.5% of a stabilizer, 0.25-1% of a plasticizer, 1-3% of a smoke inhibitor, 2-3% of a flexibilizer, 0.3-0.5% of a lubricant, and 0.4-1.5% of the supercritical CO2, wherein the stabilizer is selected from a calcium-zinc thermal stabilizer; the plasticizer is selected from a citrate plasticizer; a flame retardant and the smoke inhibitor are selected from zinc hydroxystannate; the flexibilizer is selected from MBS (Methacrylate-Butadiene-Styrene); and the lubricant is selected from oxidized polyethlene wax. The heat-resistant composite has the characteristics that the performance is excellent, the heat resistance is good, and an extruding processing method of the heat-resistant composite is simple in process and has low requirement on equipment.

Description

technical field [0001] The present invention relates to a kind of polyvinyl chloride composite material, specifically, relate to a kind of based on supercritical CO 2 Extruded and foamed CPVC / PVC heat-resistant composite material and its preparation method. Background technique [0002] Polyvinyl chloride (PVC) is an amorphous compound, containing microcrystals with a crystallinity of 5-10% (Tm 175°C), a density of 1.35-1.45, a glass state at 85°C, and a viscoelastic state at 85°C to 175°C ; No obvious melting point, molten state at 175-190°C, viscous fluid state at 190-200°C, embrittlement temperature of -50-60°C, softening point of 75-85°C, glass transition temperature of 80°C, 100°C It begins to decompose, decomposes rapidly above 180°C, and decomposes violently above 200°C. PVC is a high cost-effective polymer with a large amount of general plastics, wide application, and good comprehensive performance. The advantages of PVC are flame retardant, wear-resistant, chemica...

AI Technical Summary

Problems solved by technology

[0003] 1. Poor heat resistance, the operating temperature under normal conditions is less than 70°C, which limits its application in automobiles, ships, aircraft, and military;

[0004] 2. The flame retardant performance is not good, and it is easy to produce thick smoke and toxic gases. It is the number one killer of human life in fire, which limits its use in civil buildings;

[0005] 3. The relative molecular weight is small, the melt has poor encapsulation of gas, and it is not easy to perform foaming processing, and a large amount of foaming agent is required to foam

[0010] 4. Easy to foam processing

[0012] 1. CPVC is more brittle than PVC, so a large amount of toughening agent must be used, and the use of toughening agent reduces its precious heat resistance;

[0013] 2. Compared with PVC, CPVC has higher melt viscosity and processing temperature, and the processing is more difficult;

[0014] 3. Poor thermal stability. The dynamic thermal stability time of CPVC is much shorter than that of PVC. In the same thermal stability system, CPVC is more likely to release hydrogen chloride during processing;

[0015] 4. The adhesion of CPVC to metal is greater than that of PVC, and the melt is easy to stick to the wall during processing, which requires high processing equipment;

[0016] 5. The price is high, 3 to 4 times that of PVC resin

However, adding a large amount of plasticizer will have a great impact on the performance of the material, especially the heat resistance