Mechanochromic high-toughness nylon 6 and preparation method thereof

A technology that causes color change and high toughness. It is applied in the field of mechanochromic high toughness nylon 6 and its preparation. It can solve the problems of poor impact resistance, low toughness, discoloration of spiropyran, etc., so as to improve reliability and sensitivity and improve toughness. , the effect of improving the effectiveness

Active Publication Date: 2020-09-22
WUHAN TEXTILE UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the force-sensitive color-changing self-healing smart nylon 6 is mainly suitable for the preparation of nylon fibers, which has the problems of low toughness and poor impact resistance, which is not conducive to the preparation of structural parts; The free volume required for the configuration transformation before and after the color change of the pyran chromophore makes the spiropyran unable to effectively bear the force and change color

Method used

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  • Mechanochromic high-toughness nylon 6 and preparation method thereof
  • Mechanochromic high-toughness nylon 6 and preparation method thereof
  • Mechanochromic high-toughness nylon 6 and preparation method thereof

Examples

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Effect test

preparation example Construction

[0032] The preparation method of the mechanochromic high-toughness nylon 6 provided by the invention comprises the following steps:

[0033] S1. Polymerize diisocyanate with a molar ratio of 1.1:1 to 1.3:1 and polyether diol at 80 to 90° C. After reacting for 2 to 4 hours, an isocyanate-terminated polyurethane prepolymer is prepared. The process is as follows:

[0034]

[0035] Wherein R is one or more of hexamethylene, diphenylmethane, and methanephenyl, and R' is one or more of polyethylene glycol, polypropylene glycol, and polytetramethylene glycol.

[0036]The key point of this step is that the diisocyanate needs to be in excess to ensure that the end groups are isocyanate groups. By adjusting the reaction temperature and reaction time, the molecular weight and purity of the isocyanate-terminated polyurethane prepolymers are controlled to prepare different Lizhi Nylon 6 with color change responsive properties.

[0037] S2. Add the isocyanate-terminated polyurethane pr...

Embodiment 1

[0044] The mechanochromic high-toughness nylon 6 provided in Example 1 is prepared through the following steps:

[0045] S1. Preparation of isocyanate-terminated polyurethane prepolymer: According to n(NCO):n(OH)=1.2:1, weigh toluene diisocyanate and polypropylene glycol respectively, add polypropylene glycol into a three-necked flask, and heat at 110°C After drying under reduced pressure for 2 hours, lower the reaction temperature to 85° C., add toluene diisocyanate, and react at constant temperature for 3 hours to obtain an isocyanato-terminated polyurethane prepolymer with a molecular weight of 1800 g / mol.

[0046] S2. Preparation of isocyanato-terminated spiropyran derivatives: according to n(NCO):n(OH)=1.2:1, respectively weigh the isocyanato-terminated polyurethane prepolymer and dihydroxy spiropyran, and It was placed in a reaction flask, and then the catalyst dibutyltin dilaurate (DBTDL) was added into the reaction flask, and stirred at 85° C. for 2 h to obtain an isoc...

Embodiment 2~5

[0052] Compared with Example 1, the mechanochromic high-toughness nylon 6 provided in Examples 2-5 differs in that the preparation conditions in Step S1 and the molecular weight of the isocyanato-terminated polyurethane prepolymer are shown in Table 1 , and others are substantially the same as those in Embodiment 1, and will not be repeated here.

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Abstract

The invention provides mechanochromic high-toughness nylon 6 and a preparation method thereof. The preparation method comprises the following steps: firstly, preparing an isocyanate-terminated polyurethane prepolymer; then, enabling excessive terminal isocyanate groups to react with hydroxyl groups of spiropyrane chromophore; adding an isocyanate-terminated spiropyrane derivative into caprolactammelt, carrying out an addition reaction on isocyanate and caprolactam, and finally injecting the mixture into a mold to carry out an anionic polymerization reaction to obtain the mechanochromic high-toughness nylon 6. According to the invention, the raw material ratio and reaction conditions are reasonably controlled, polyurethane chain segments and spiropyrane chromophore are introduced into a polyamide molecular chain, the position relation and molecular weight between the chain segments are reasonably regulated and controlled, the effectiveness of external force transmission of the preparedmechanochromic high-toughness nylon 6 is remarkably improved, and then the sensitivity of mechanochromic response of the spiropyrane chromophore is remarkably improved.

Description

technical field [0001] The invention belongs to the technical field of intelligent materials, and in particular relates to a mechanochromic high-toughness nylon 6 and a preparation method thereof. Background technique [0002] As one of the five major engineering plastics, polyamide (nylon) has the characteristics of high tensile strength, large elastic modulus, excellent wear resistance and self-lubrication, and is widely used in automobile manufacturing, electronic and electrical industries, mechanical equipment and packaging industries. be widely used. However, when nylon material is used as a structural part in the machinery industry, because of its high brittleness and low toughness, the alternating stress during use is likely to cause fatigue cracks inside the nylon material and lead to early failure of the material, shortening its service life. In addition, when fatigue cracks occur inside the nylon material, users cannot intuitively discover and predict its microsco...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08G69/40
CPCC08G69/40
Inventor 王雯雯田时友李嫚丽郑玉竹王栋陈媛丽
Owner WUHAN TEXTILE UNIV
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