Polypropylene microsphere and preparation method therefor, 3D printing raw material, and use
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Solution Overview
Problem
Existing methods for preparing polypropylene microspheres for 3D printing and foaming materials result in irregular shapes, poor fluidity, and uneven crystallization distribution, leading to unsatisfactory performance and production instability.
Innovation Solution
A polypropylene microsphere is prepared through direct copolymerization with 0.2 wt% to 10 wt% ethylene and 90 wt% to 99.8 wt% propylene, using a specific catalyst system comprising a magnesium-containing compound, titanium compound, and electron donor compounds, resulting in a half-peak width of 4-10°C and a molecular weight distribution of 4-9, with a spherical morphology and improved fluidity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If pulverization method (cryogenic pulverization) is used to prepare polypropylene powder, then powder can be obtained, but particles have rough surface, non-uniform particle diameter, irregular shape, and poor fluidity
Solution Approach 1:
The patent changes the fundamental parameter of particle formation from mechanical pulverization to chemical polymerization. By controlling polymerization conditions (catalyst system, temperature, pressure, monomer ratio), spherical particles with uniform diameter (0.5-2.0mm) and smooth surfaces are directly formed, eliminating the need for subsequent size classification and improving fluidity (angle of repose 20-30°).
Solution Approach 2:
The patent uses a composite catalyst system comprising Mg-containing compound, Ti compound, and electron donor compounds. This composite catalyst enables controlled polymerization that produces particles with uniform morphology and size distribution, directly resolving the particle uniformity issue without requiring extensive post-processing.
2Productivity
If precipitation method is used to prepare polymer powder, then powder can be obtained, but large amount of organic solvent is required, yield and efficiency are low
Solution Approach 1:
The patent extracts and eliminates the precipitation step entirely from the process flow. By using solution polymerization followed by direct filtration and drying, the method removes the need for solvent-intensive precipitation operations, reducing organic solvent consumption and improving production efficiency without compromising particle quality.
Solution Approach 2:
The patent replaces the mechanical precipitation process with a controlled polymerization reaction system. Instead of dissolving polymer in solvent and precipitating it, the method uses in-situ polymerization to form particles directly in the reaction medium, which are then easily separated by filtration, dramatically improving efficiency and reducing solvent use.
3Stability of the object's composition
If conventional polymerization methods are used for polypropylene, then polymer can be produced, but crystallization sequence distribution is uneven, melting uniformity is poor
Solution Approach 1:
The patent applies local quality control through the electron donor compounds in the catalyst system, which create specific local environments during polymerization that promote uniform isotactic crystallization sequences throughout the polymer chains. This results in consistent melting behavior and improved manufacturing precision.
Solution Approach 2:
The patent optimizes multiple parameters including catalyst composition (Mg:Ti ratio), electron donor type and amount, polymerization temperature (50-100°C), and monomer concentration to achieve uniform crystallization. These parameter adjustments ensure consistent isotactic index (95-99%) and narrow molecular weight distribution, leading to uniform melting characteristics.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The method produces polypropylene microspheres with uniform crystallization and melting, enhancing foaming ratio, reducing production costs, and improving the structural strength and surface properties of 3D printed products.
Implementation Method 1
copolymerizing propylene-containing olefins in the presence of an olefin polymerization catalyst system to obtain a polypropylene microsphere
Implementation Method 2
using a specific catalyst system comprising a magnesium-containing compound, titanium compound, and electron donor compounds
Implementation Method 3
high-intensity laser is used to irradiate material powder laid on a workbench or parts in advance to selectively melt and sinter the material powder layer by layer
Implementation Method 4
selectively melt and sinter the material powder layer by layer, thereby realizing layer-by-layer molding
Data Source
AI summary
A polypropylene microsphere and a preparation method therefor, a 3D printing raw material, and a use are provided. The polypropylene microsphere contains 0.2 wt %-10 wt % of a structural unit derived from ethylene and 90 wt %-99.8 wt % of a structural unit derived from propylene. A melting heat absorption curve of the polypropylene microsphere is obtained by means of a differential scanning calorimeter (DSC), and a half-peak width (Wm) of the melting heat absorption curve of the polypropylene microsphere is 4-10° C. The crystallization sequence distribution of the polypropylene microsphere is uniform, and when the polypropylene microsphere is used for 3D printing, 3D printing melting is uniform.