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A method for preparing polystyrene-polyvinyl alcohol double-layer hollow microspheres

A technology of polystyrene and hollow microspheres, which is applied in the preparation of microspheres and microcapsule preparations, and can solve the difficulties of preparing large-diameter PS-PVA double-layer spheres, poor surface roughness of microspheres, and poor uniformity of coating thickness, etc. problem, to achieve the effect of solving the uncontrollable thickness of polyvinyl alcohol coating, avoiding direct collision, and wide application range

Active Publication Date: 2018-04-10
LASER FUSION RES CENT CHINA ACAD OF ENG PHYSICS
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the thickness uniformity of the PVA coating obtained by the spin coating method is poor, and the traces of adsorption and drying by the vacuum device cannot be removed, and the surface roughness of the obtained microspheres is poor.
At present, the main method of preparing PVA coating at home and abroad is the emulsion microencapsulation method. Although this method is easy to operate in the preparation process, the equipment is simple, and it can produce small-sized PS-PVA double-layer balls below 500 μm with a high survival rate, but it cannot Obtain batches of double-layer microspheres with uniform wall thickness distribution. The quality of the balls is greatly affected by human factors, and there are great difficulties in preparing large-diameter PS-PVA double-layered spheres
[0004] With the application of plastic hollow microspheres in ICF physical experiments more and more widely, the size of the microspheres is various, the above three PVA coating methods cannot meet the requirements of preparing PS-PVA double-layer spheres of different sizes, and the PVA coating batches are uniform Sexuality is also difficult to effectively control
At present, there is no effective method to prepare PVA coating with controllable thickness and consistent batch thickness.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0039] This embodiment includes the following steps:

[0040] 1. Select a double-T milk particle generator with channel I, channel II and channel III having an inner diameter of 1.0mm, where channel I intersects channel II at 90°, and channel II intersects channel III at 90°;

[0041] 2. Prepare a HCl aqueous solution with pH=2, select PS hollow microspheres I with an inner diameter of 800 μm, an inner diameter deviation of ±20 μm, and water inside, soak them in an HCl aqueous solution with a pH of 2, and pass ozone into the HCl aqueous solution. The stirring speed is 80 rpm, the time is 2h, and the PS hollow microsphere II is obtained;

[0042] 3. Wash PS hollow microspheres II with distilled water three times, then soak PS hollow microspheres II in 2.5 wt% PVA solution for 24 hours at 25°C;

[0043] 4. Prepare HNO with a concentration of 10wt% 3 solution, the HNO 3 The solution is filled in the rotary evaporator, after soaking for 24h, pour out the HNO 3 solution, washed...

Embodiment 2

[0054] The steps of embodiment 2 and embodiment 1 are basically the same, the main difference is that the double T milk particle generator with the inner diameter of channel I, channel II and channel III is 1.2mm; Water-containing PS hollow microspheres Ⅰ; the ozone treatment process of PS hollow microspheres Ⅰ is the same as in Example 1, wherein the stirring speed is 60rpm to obtain PS hollow microspheres Ⅱ; PS hollow microspheres Ⅱ are soaked in 3.5 wt% PVA solution, The soaking time is 24 hours, the temperature is 25 °C; the hydrophobic treatment steps of the rotary steamer are the same as in Example 1; draw 3ml of 3.5 wt% PVA solution with a 5ml syringe, fix the syringe on a micro-injection pump, and pass a 1.2mm diameter glass capillary through a rubber hose and Connect with a 5ml syringe, draw PS hollow microspheres II into the glass capillary in turn, and connect with channel I through a polytetrafluoroethylene (PTFE) nut; draw 5ml 3.5 wt% PVA solution with a 5ml syring...

Embodiment 3

[0057] The steps of embodiment 3 are basically the same as those of embodiment 1, the main difference is that the double T milk particle generator with inner diameters of channel I, channel II and channel III are all 1.5mm; Water-containing PS hollow microspheres Ⅰ; the ozone treatment process of PS hollow microspheres Ⅰ is the same as in Example 1, wherein the stirring speed is 50rpm to obtain PS hollow microspheres Ⅱ; PS hollow microspheres Ⅱ are soaked in 4.5 wt% PVA solution, The soaking time is 24 hours, the temperature is 25°C; the hydrophobic treatment steps of the rotary steamer are the same as in Example 1; draw 3ml of 4.5 wt% PVA solution with a 5ml syringe, fix the syringe on a micro-injection pump, and pass a glass capillary with a diameter of 1.5mm through the rubber hose and Connect with a 5ml syringe, draw PS hollow microspheres II into the glass capillary in turn, and connect to the channel I through a polytetrafluoroethylene (PTFE) nut; draw 5ml of 4.5 wt% PVA ...

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PUM

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Abstract

The invention provides a method for preparing polystyrene-polyvinyl alcohol double-layer hollow microspheres. The method improves the yield of PVA-coated PS microspheres by changing the PVA solution concentration and the ratio of the oil-phase organic solution; adjusts the relative size of the PVA solution concentration and the three-phase flow rate to control the thickness of the PVA layer; Hydrophobic pretreatment of steamer, adjustment of rotation speed and curing temperature, improve the hydrophilic combination between PS‑PVA composite emulsion particles and rotary steamer during curing process, and avoid direct collision and merging of PS‑PVA composite emulsion particles , effectively improved the quality of the PVA coating, and successfully prepared PS-PVA double-layer hollow microspheres with an inner diameter of 800 μm to 1300 μm and a polyvinyl alcohol layer thickness deviation of 1 μm. The method can change the channel diameter of the generator according to the requirement of the target microsphere diameter, and has simple operation and wide application range.

Description

technical field [0001] The invention belongs to the field of polymer processing and molding, and in particular relates to a method for preparing polystyrene-polyvinyl alcohol double-layer hollow microspheres. Background technique [0002] In recent years, polymer hollow microspheres based on low atomic numbers such as C and H have received extensive attention and research in the field of laser inertial confinement fusion (ICF), among which three-layer polymer hollow microspheres are polystyrene (PS) -Polyvinyl alcohol (PVA)-hydrocarbon polymer (CH) hollow microspheres play an important role in the experimental research of ICF. However, PS and CH layers have poor barrier properties to hydrogen, which cannot meet the requirements of physical experiments, while PVA has good barrier properties to hydrogen and excellent ball forming performance, and high-quality gas-retaining coatings can be obtained. Therefore, PVA coatings Layer technology is the most widely studied. [0003]...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): B01J13/02
Inventor 李洁初巧妹苏琳陈素芬刘梅芳李婧刘一杨李波张占文
Owner LASER FUSION RES CENT CHINA ACAD OF ENG PHYSICS