CN-122011480-A - Ultralow-temperature-resistant polyurea foam and preparation method and application thereof

CN122011480ACN 122011480 ACN122011480 ACN 122011480ACN-122011480-A

Abstract

The invention discloses ultralow temperature resistant polyurea foam and a preparation method and application thereof, wherein the preparation method comprises the following steps of step 1, carrying out ring opening reaction and polycondensation reaction on amino double-end-capped polydimethylsiloxane and ethylene carbonate to obtain polyurea containing a monoureido structure; and 2, mixing the polyurea, the polymethylhydrosiloxane and the catalyst to obtain a premix, and foaming to obtain the polyurea foam. The foam is prepared by taking polyurea prepared by amino double-end-capped polydimethylsiloxane and ethylene carbonate through a non-isocyanate route as a matrix, taking polymethylhydrosiloxane as a cross-linking agent and a foaming agent, and performing cross-linking foaming through a one-step method. The polyurea foam has a spaced cross-linking structure, and ureido groups are separated by flexible PDMS chain segments, so that the material can still keep chain segment mobility and dynamic hydrogen bond recombination capability at extremely low temperature. Has excellent impact resistance and elastic recovery capability, and is suitable for extreme environments such as aerospace, polar equipment and the like.

Inventors

HAN LIJING
ZHANG RUOYU
XIANG LINGCHAO
YANG WENYU
XU JIACHENG
DUAN XUEMING
ZHANG MENGBO
ZHANG HAIYI
WANG GETAO
XIAO XUNWEN

Assignees

宁波市第二医院
宁波工程学院
中国科学院宁波材料技术与工程研究所

Dates

Publication Date: 20260512
Application Date: 20260209

Claims (10)

1. A method for preparing ultralow temperature resistant polyurea foam, which is characterized by comprising the following steps: step 1, performing ring opening reaction and polycondensation reaction on amino double-end-capped polydimethylsiloxane and ethylene carbonate to obtain polyurea containing a monoureido structure; And 2, mixing the polyurea, the polymethylhydrosiloxane and the catalyst to obtain a premix, and foaming to obtain the polyurea foam.
2. The method for preparing the ultralow temperature resistant polyurea foam according to claim 1, wherein the molar ratio of the ethylene carbonate to the amino double-end-capped polydimethylsiloxane is 1-1.5:1.
3. The method for preparing an ultralow temperature resistant polyurea foam according to claim 1, wherein the amino double-blocked polydimethylsiloxane has a number average molecular weight of 300-2500 g/mol.
4. The method for preparing the ultralow temperature resistant polyurea foam according to claim 1, wherein the ring-opening reaction is carried out at 60-100 ℃ for 5-10 hours, the temperature of the melt polycondensation reaction is 170-200 ℃, and the reaction is finished by taking the stirring paddles at which the reactants begin to adhere.
5. The method for preparing the ultralow temperature resistant polyurea foam according to claim 1, wherein the polymethylhydrosiloxane has a viscosity of 10-100 mPa s at 20 ℃, and the mass fraction of active hydrogen is 0.1-2%.
6. The method for preparing the ultralow temperature resistant polyurea foam according to claim 1, wherein in the step2, the molar ratio of ureido groups in the polyurea to active hydrogen in the polymethylhydrosiloxane is 1:1-5.
7. The preparation method of the ultralow temperature resistant polyurea foam according to claim 1, wherein the catalyst is chloroplatinic acid or carboplatin catalyst, and the mass of the catalyst is 0.01-0.1% of the total mass of reaction raw materials.
8. The method for preparing the ultralow temperature resistant polyurea foam according to claim 1, wherein the foaming temperature is 65-120 ℃ and the foaming time is 30-90min.
9. Ultralow temperature resistant polyurea foam produced by the production process according to any one of claims 1 to 8.
10. The use of the ultra-low temperature resistant polyurea foam according to claim 9 in an ultra-low temperature environment, wherein the ultra-low temperature environment is an ambient temperature below-50 ℃.

Description

Ultralow-temperature-resistant polyurea foam and preparation method and application thereof Technical Field The invention relates to the technical field of low-temperature material preparation, in particular to ultralow-temperature-resistant polyurea foam and a preparation method and application thereof. Background With the rapid development of the fields of polar exploration, aerospace, low-temperature engineering, extreme environment transportation, etc., there is an urgent need for foam materials that can maintain excellent impact resistance and toughness in extremely low-temperature environments. Taking space garbage disposal as an example, with the increasing number of human launching spacecraft, space debris on the near-earth orbit has become a reality and increasingly serious threat. Although various cleaning solutions have been proposed, there are currently no solutions available for collecting these space debris that are both economical and viable. In this context, foam materials with very low temperature toughness and high impact resistance provide a new concept for capturing these constantly tumbling space floats. However, under extremely low temperature environment, the conventional polymer foam material is embrittled due to limited chain segment movement, and the impact resistance and toughness are drastically reduced, so that the requirements of the fields of aerospace, polar equipment, deep space exploration and the like on impact resistant materials cannot be met. Therefore, development of a class of super-tough foam materials capable of maintaining high impact resistance in an extremely low temperature environment has become an important point of research and a technical bottleneck in this field. Several low temperature resistant foams are reported in the prior art, such as a preparation method of a nanoparticle-reinforced low temperature resistant and impact resistant foam material disclosed in CN115746239A, wherein the foam material is formed by foaming and curing silica nanoparticles, a low temperature resistant polyol combination material and isocyanate, and the preparation method comprises the following steps of preparing the low temperature resistant polyol combination material, wherein the preparation method comprises the steps of mixing a polymer polyol mixture with an auxiliary agent to form the low temperature resistant polyol combination material; and adding isocyanate into the first mixture, rapidly and uniformly stirring, pouring into a mold for foaming, curing at constant temperature, and demolding to obtain the nanoparticle-based reinforced low-temperature-resistant impact-resistant foam material. The auxiliary agent comprises a foam homogenizing agent, a catalyst and a solid accelerator, and the polymer polyol mixture comprises one or more of a polyoxypropylene polyol with higher molecular weight, a polyether polyol with medium and low molecular weight, polyethylene glycol and 1, 4-butanediol, but only meets the low-temperature use requirement of low temperature of-18 to-40 ℃. The material comprises 60-120 parts of polyether polyol, 1-5 parts of foaming agent, 0.1-2 parts of foam stabilizer, 0.05-1 part of catalyst, 60-130 parts of toluene diisocyanate, 0.5-5 parts of chain extender and 0.5-10 parts of shear thickening gel, wherein the catalyst is a composite formula of an etheramine catalyst and an organotin catalyst, and the mass ratio of the etheramine catalyst to the organotin catalyst is 1:0.3-3. The preparation method comprises the steps of (1) mixing polyether polyol, a foaming agent, a catalyst, a foam stabilizer, a chain extender and a shear thickening gel, stirring at a high speed for 60-180s, adding toluene diisocyanate, stirring at a rotating speed of 1500-2000r/min for 5-30s to obtain a material, and pouring the material into a mold for foaming for 6-10min to obtain the material. The material has no brittle fracture phenomenon after heat preservation for 24 hours at the low temperature of-30 to-40 ℃, and can be used under severe cold, such as polar skiing, soldier severe cold training and the like. While foams having excellent impact properties at lower temperatures are not disclosed. Disclosure of Invention Aiming at the problems of insufficient mechanical property and easy embrittlement in an ultralow temperature environment (-50 ℃ below), the invention provides the polyurea foam with excellent impact resistance in the ultralow temperature environment, and the polyurea foam has the advantages that the ureido groups are separated by the flexible Polydimethylsiloxane (PDMS) chain segments through the design of a space crosslinking structure to realize high energy absorption and dissipation capacity in the ultralow temperature, so that a new technical scheme is provided for solving the problem of foam application scene limitation. In order to achieve the above purpose, the invention adopts the following technical scheme: A method for preparing ultralow temperatur