阅读说明：本技术 核磁共振氢谱定量检测涤纶织物中间苯二甲酸含量的方法 (Method for quantitatively detecting content of isophthalic acid in polyester fabric by nuclear magnetic resonance hydrogen spectrum ) 是由 程琳 白露 于 2020-12-29 设计创作，主要内容包括：一种核磁共振氢谱定量检测涤纶织物中间苯二甲酸含量的方法,首先对涤纶织物进行预处理得到纯化后的固体样品,然后将纯化后的固体样品溶于氘代试剂中,进行核磁共振氢谱测试,得到核磁共振氢谱数据；然后将测试核磁共振氢谱数据通过MestReNova软件进行数据处理,矫正基线,定峰和峰积分后计算得到间苯二甲酸含量,从而能够方便的检测涤纶织物中间苯二甲酸的含量,且本发明测试分析方法操作较为简便,采用核磁共振仪分析涤纶织物中间苯二甲酸的含量较为准确,便于实际工业中对涤纶织物中间苯二甲酸含量的精确控制和质量把关。(A method for quantitatively detecting the content of phthalic acid in polyester fabric by using a nuclear magnetic resonance hydrogen spectrum comprises the steps of firstly pretreating the polyester fabric to obtain a purified solid sample, then dissolving the purified solid sample in a deuterated reagent, and performing a nuclear magnetic resonance hydrogen spectrum test to obtain nuclear magnetic resonance hydrogen spectrum data; and then the data of the test nuclear magnetic resonance spectrum is subjected to data processing through MestReNova software, a base line is corrected, and the content of the isophthalic acid is calculated after peak fixing and peak integration, so that the content of the isophthalic acid in the polyester fabric can be conveniently detected.)

1. A method for quantitatively detecting the content of isophthalic acid in polyester fabrics by nuclear magnetic resonance hydrogen spectrum is characterized by comprising the following steps: comprises the following steps;

cutting a polyester fabric sample, putting the cut polyester fabric sample into a glass cup, adding trifluoroacetic acid and chloroform, wherein the trifluoroacetic acid: the ratio of chloroform is 1:9-1:2, after the polyester fabric is fully dissolved, the polyester fabric is dripped into a methanol solution to separate out solids, and the samples are circularly dissolved and separated out for 3-5 times to obtain purified solid samples;

step two, putting the obtained purified solid sample into a vacuum drying oven, drying for 12-24h at the temperature of 80-120 ℃, weighing 10-20mg of the purified and dried polyester fabric sample, putting the sample into a nuclear magnetic tube, and adding a deuterated reagent;

thirdly, sending the sample dissolved in the deuterated reagent into a nuclear magnetic resonance spectrometer for hydrogen spectrum test to obtain nuclear magnetic resonance hydrogen spectrum data;

and step four, carrying out data processing on the tested nuclear magnetic resonance hydrogen spectrum data through MestReNova software, correcting a base line, and calculating after peak fixing and peak integration to obtain the content of the isophthalic acid.

2. The method for quantitatively detecting the content of the isophthalic acid in the polyester fabric by the nuclear magnetic resonance hydrogen spectrum according to claim 1, which is characterized in that: and the deuterated reagent in the second step comprises deuterated chloroform and deuterated trifluoroacetic acid or a mixed solution of the deuterated chloroform and the deuterated trifluoroacetic acid.

3. The method for quantitatively detecting the content of the isophthalic acid in the polyester fabric by the nuclear magnetic resonance hydrogen spectrum according to claim 1, which is characterized in that: and in the fourth step, an Avance II 400MHz nuclear magnetic resonance spectrometer is adopted for the nuclear magnetic resonance hydrogen spectrum test.

Technical Field

The present invention relates to the field of analytical testing. More particularly, relates to a method for quantitatively detecting the content of isophthalic acid in polyester fabrics by nuclear magnetic resonance hydrogen spectroscopy.

Background

The terylene, namely the polyethylene terephthalate (PET fiber), has regular PET molecular chains and is easy to crystallize, and the crystal region has great influence on the transparency of the polymer. Isophthalic acid is often used to produce modified polyethylene terephthalate resins (PET). The addition of the isophthalic acid can reduce the regularity of PET molecular chains, so that the crystallization rate and the crystallinity of the copolymer are reduced, and a product with higher transparency can be produced. The lower crystallinity also reduces the melting temperature of the copolymer, thereby also reducing the processing and forming temperature of the material, and the lower processing temperature can reduce the amount of byproduct, namely, acetaldehyde, generated by the thermal decomposition of the polymer, and improve the production safety factor. Because the isophthalic acid modified PET resin can not only reduce the production cost in the production process, but also has excellent product performance and few byproducts, the isophthalic acid modified PET resin has larger and larger share in the market.

Isophthalic acid, also known as isophthalic acid, 1, 3-phthalic acid, however, has a irritating effect on the eyes, mucous membranes and skin. Symptoms such as cough, dyspnea, throat pain and vomiting appear after respiratory inhalation, and skin allergy can be caused by long-term contact. Therefore, in the polyester fabric manufactured by modifying PET by using isophthalic acid, the control and detection of the content of the isophthalic acid are particularly important.

Disclosure of Invention

In order to solve the technical problems, the invention provides a method for quantitatively detecting the content of isophthalic acid in polyester fabric by using a nuclear magnetic resonance hydrogen spectrum, and in order to achieve the purpose, the technical scheme adopted by the invention is as follows:

a method for quantitatively detecting the content of isophthalic acid in polyester fabric by using a nuclear magnetic resonance hydrogen spectrum comprises the following steps;

cutting a polyester fabric sample, putting the cut polyester fabric sample into a glass cup, adding trifluoroacetic acid and chloroform, wherein the trifluoroacetic acid: the ratio of chloroform is 1:9-1:2, after the polyester fabric is fully dissolved, the polyester fabric is dripped into a methanol solution to separate out solids, and the samples are circularly dissolved and separated out for 3-5 times to obtain purified solid samples;

step two, putting the obtained purified solid sample into a vacuum drying oven, drying for 12-24h at the temperature of 80-120 ℃, weighing 10-20mg of the purified and dried polyester fabric sample, putting the sample into a nuclear magnetic tube, and adding a deuterated reagent;

thirdly, sending the sample dissolved in the deuterated reagent into a nuclear magnetic resonance spectrometer for hydrogen spectrum test to obtain nuclear magnetic resonance hydrogen spectrum data;

and step four, carrying out data processing on the tested nuclear magnetic resonance hydrogen spectrum data through MestReNova software, correcting a base line, and calculating after peak fixing and peak integration to obtain the content of the isophthalic acid.

Further, the deuterated reagent in the second step comprises deuterated chloroform, deuterated trifluoroacetic acid or a mixed solution of deuterated chloroform and deuterated trifluoroacetic acid.

Furthermore, an Avance II 400MHz nuclear magnetic resonance spectrometer is adopted for the nuclear magnetic resonance hydrogen spectrum test in the fourth step.

Compared with the prior art, the invention has the following beneficial effects;

1. firstly, preprocessing a polyester fabric to obtain a purified solid sample, then dissolving the purified solid sample in a deuterated reagent, and performing nuclear magnetic resonance hydrogen spectrum test to obtain nuclear magnetic resonance hydrogen spectrum data; and then carrying out data processing on the tested nuclear magnetic resonance hydrogen spectrum data through MestReNova software, correcting a base line, and calculating after peak fixing and peak integration to obtain the content of the isophthalic acid, so that the content of the isophthalic acid in the polyester fabric can be conveniently detected.

2. The method for quantitatively detecting the content of the phthalic acid in the polyester fabric by using the nuclear magnetic resonance hydrogen spectrum has the advantages of simple and convenient operation, accurate analysis of the content of the phthalic acid in the polyester fabric by using a nuclear magnetic resonance spectrometer, and convenience for accurate control and quality control of the content of the phthalic acid in the polyester fabric in the actual industry.

Drawings

FIG. 1 is a nuclear magnetic resonance hydrogen spectrum of a polyester fabric sample obtained in example 1 of the present invention.

FIG. 2 is a hydrogen spectrum of terephthalic acid in a NMR database.

FIG. 3 is a hydrogen spectrum of isophthalic acid in a NMR database.

FIG. 4 is an integral chart of the NMR data analysis of the polyester fabric sample obtained in example 1 of the present invention.

Detailed Description

The following describes embodiments of the present invention in detail and completely. The following examples are only used to more clearly illustrate the technical solutions of the present invention, and therefore, only serve as a part of the implementation examples, and the protection scope of the present invention is not limited thereby. Based on the implementation examples in the present invention, other implementation examples obtained by a person of ordinary skill in the art without any creative effort belong to the protection scope of the present invention.

Example one

A method for quantitatively detecting the content of isophthalic acid in polyester fabric by using a nuclear magnetic resonance hydrogen spectrum comprises the following steps;

firstly, shearing a polyester fabric sample, putting the cut polyester fabric sample into a glass cup, adding 1ml of trifluoroacetic acid and 10ml of chloroform, shaking up to fully dissolve the polyester fabric, dripping the polyester fabric into 50ml of methanol solution to separate out solids, and circularly dissolving and separating out the sample for 3 times to obtain a purified solid sample;

step two, putting the obtained purified solid sample into a vacuum drying oven for drying treatment for 12h at the temperature of 80 ℃, weighing 10mg of the purified and dried polyester fabric sample, putting the polyester fabric sample into a 5mm nuclear magnetic tube, and sequentially adding 0.1ml of deuterated trifluoroacetic acid and 0.5ml of deuterated chloroform;

thirdly, sending the sample dissolved in the deuterated reagent into a vance II 400MHz nuclear magnetic resonance spectrometer for hydrogen spectrum test to obtain nuclear magnetic resonance hydrogen spectrum data;

step four, processing the obtained data of the hydrogen spectrum of the sample by using MestReNova software, correcting a base line and calibrating the peak of the obtained data of the hydrogen spectrum of the sample as shown in fig. 1, wherein 11.32 is the calibrated hydrogen spectrum peak of deuterated trifluoroacetic acid, 8.17 is the hydrogen spectrum peak of terephthalic acid, 7.26 is the hydrogen spectrum peak of deuterated chloroform, as shown in fig. 2, the four para-position H spectrum peaks of the terephthalic acid are all 8.09 as shown in fig. 3, the four hydrogen spectrum peaks of the isophthalic acid are 7.99, 8.49, 8.55 and 8.49 respectively, as shown in fig. 4, the hydrogen spectrum is analyzed by using the mesrenova software, as shown in fig. 4, the peak area of the spectrum of the isophthalic acid at 7.99 is integrated to be 1, the H of the isophthalic acid is integrated in the peak area of 8.09, the integrated area is 752.99, and the content of the isophthalic acid is calculated to be 1 752.99/4/(0.5), the content of the isophthalic acid is 0.5%, the test analysis method is simple and convenient to operate, the nuclear magnetic resonance spectrometer is adopted to analyze the content of the isophthalic acid in the polyester fabric accurately, and the accurate control and quality control of the content of the isophthalic acid in the polyester fabric in the actual industry are facilitated.

Example two

A method for quantitatively detecting the content of isophthalic acid in polyester fabric by using a nuclear magnetic resonance hydrogen spectrum comprises the following steps;

firstly, shearing a polyester fabric sample, putting the cut polyester fabric sample into a glass cup, adding 2ml of trifluoroacetic acid and 5ml of chloroform, shaking up to fully dissolve the polyester fabric, dripping the polyester fabric into 20ml of methanol solution to separate out solids, and circularly dissolving and separating out the sample for 3 times to obtain a purified solid sample;

step two, putting the obtained purified solid sample into a vacuum drying oven for drying treatment for 12h at 100 ℃, weighing 10mg of the purified and dried polyester fabric sample, putting the polyester fabric sample into a 5mm nuclear magnetic tube, and sequentially adding 0.2ml of deuterated trifluoroacetic acid and 0.5ml of deuterated chloroform;

thirdly, sending the sample dissolved in the deuterated reagent into a vance II 400MHz nuclear magnetic resonance spectrometer for hydrogen spectrum test to obtain nuclear magnetic resonance hydrogen spectrum data;

and fourthly, carrying out data processing analysis on the obtained sample hydrogen spectrum data by using MestReNova software to obtain the content of the phthalic acid in the polyester fabric.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the invention has been described in detail with reference to the foregoing illustrative embodiments, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the spirit and scope of the technical solutions of the embodiments of the present invention.