CN113930997B

CN113930997B - Method for preparing foam material from bagasse thermomechanical pulp based on ozone modification

Info

Publication number: CN113930997B
Application number: CN202111078212.8A
Authority: CN
Inventors: 李军; 廖建明
Original assignee: Foshan Xinzhidao Environmental Protection Technology Co ltd; South China University of Technology SCUT
Current assignee: Foshan Xinzhidao Environmental Protection Technology Co ltd
Priority date: 2021-09-15
Filing date: 2021-09-15
Publication date: 2022-08-02
Anticipated expiration: 2041-09-15
Also published as: CN113930997A

Abstract

The invention provides a method for preparing a foam material based on ozone-modified bagasse thermomechanical pulp, which specifically comprises the following steps: step 1: taking a certain amount of absolute dry bagasse thermomechanical pulp, and adjusting the pulp concentration to be 30% by using distilled water; step 2: introducing ozone into the adjusted mechanical pulp and reacting for a period of time; and step 3: adjusting the mechanical pulp obtained in the step 2 to a certain concentration by using distilled water, and pulping; and 4, step 4: preparing the pulped mechanical pulp into a paper pulp suspension with the concentration of 2%, adding a foaming agent A and a foaming agent B, and uniformly mixing; and 5: and (5) stirring the slurry obtained in the step (4) for a period of time to obtain the foam material.

Description

Method for preparing foam material from bagasse thermomechanical pulp based on ozone modification

Technical Field

The invention relates to the field of preparation of foam materials, in particular to a method for preparing a foam material based on ozone-modified bagasse thermomechanical pulp.

Background

The foam material has the characteristics of light weight, high strength, good buffering performance, good heat and sound insulation performance and the like, so the foam material is widely applied to the fields of industry, agriculture, buildings, traffic, packaging and the like. In general, foams (e.g., expanded polystyrene and polyurethane foams) are made from petrochemical materials, are difficult to recycle, and are not biodegradable, thus polluting the environment and endangering human health. According to previous studies, a large amount of plastic wastes are produced worldwide every year, about 9% are recovered, 12% are incinerated, and 79% are stacked in a dump or natural environment. Some plastics take hundreds of years or even thousands of years to degrade, especially disposable foams, plastic bags and packaging boxes. With the growth of the concept of sustainable development around the world, biodegradable foams are entering an accelerated research phase. Therefore, the development of a biodegradable and recyclable pulp fiber foam which can meet quality parameters to replace the traditional fossil petroleum-based foam products has fundamental and practical significance.

Pulp fiber foams are usually prepared from bleached pulp, but the cost of the bleached pulp is too high, which results in very limited application fields of the foam materials, and therefore, the development of a raw material with low cost and good performance is required. Mechanical pulp is a process in which plant fibers are treated with no or little chemicals and then disintegrated into pulp using mechanical energy. Due to the advantages of high yield, low pollution and the like, the method is continuously developed in recent decades. However, because a large amount of lignin exists on the surface of the mechanical pulp fiber, the paper pulp is difficult to be devillicate and broomed in the beating process, and most of the fiber is mainly cut off, so that the thermo-grinding machine is modified, the devillicate and brooming can be carried out more easily, the beating energy consumption is reduced, and the performance of the material is improved. Ozone is a strong oxidant, has strong selectivity to lignin, and can be directly reacted with lignin on the surface of the fiber by mixing with mechanical pulp under the condition of high concentration, so that the structure of the surface of the fiber is changed. The modified thermomechanical pulp fiber is easier to be devillicate and broomed, so that more hydrogen bonds are exposed, and finally, the foam material prepared from the modified thermomechanical pulp has better performance.

Disclosure of Invention

The invention mainly aims to provide a preparation method of ozone modified bagasse thermomechanical pulp and a foam material, which has the advantages of simplicity, low cost, high efficiency and obvious advantages in the aspects of improvement of the performance of a pulp fiber foam material and cost control.

In order to achieve the above purposes, the technical scheme adopted by the invention is as follows: a method for preparing a foam material based on ozone modified bagasse thermomechanical pulp is characterized by comprising the following steps:

step 1: taking a certain amount of absolute dry bagasse thermomechanical pulp, and adjusting the pulp concentration to be 30% by using distilled water;

and 2, step: introducing ozone into the adjusted mechanical pulp and reacting for a period of time;

and step 3: adjusting the mechanical pulp obtained in the step 2 to a certain concentration by using distilled water, and pulping;

and 4, step 4: preparing the pulped mechanical pulp into a paper pulp suspension with the concentration of 2%, adding a foaming agent A and a foaming agent B, and uniformly mixing;

and 5: and (4) stirring the slurry obtained in the step (4) for a period of time to obtain the foam material.

Preferably, the concentration of the pulp suspension in step 4 is 2% -5%.

Preferably, in step 3, beating is performed by a beater, the number of beating revolutions being 9000 r.

Preferably, in step 4, blowing agent A and blowing agent B are used in amounts of 4% and 25%, respectively.

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

the mechanical pulp is modified by ozone before pulping, so that fibers of the mechanical pulp can be more easily broomed, and the foam material has better elasticity; the method has the advantages of low pulping energy consumption, low cost of the foam material prepared by the paper pulp and obviously improved performance.

Drawings

FIG. 1(a) is a SEM photograph of bagasse thermomechanical pulp fibers after devillicating before ozone modification;

FIG. 1(b) is an SEM photograph of the bagasse thermomechanical pulp fiber after being modified with ozone after being devillized;

FIG. 2 foam obtained by the process of the invention.

Detailed Description

The following description is presented to disclose the invention so as to enable any person skilled in the art to practice the invention. The preferred embodiments in the following description are given by way of example only, and other obvious variations will occur to those skilled in the art.

Example 1

A method for preparing a foam material based on ozone-modified bagasse thermomechanical pulp specifically comprises the following steps:

step 1: taking 50g of oven-dried bagasse thermomechanical pulp, adjusting the pulp concentration to 30% by using distilled water, placing the adjusted paper pulp in a stainless steel reaction tank for uniform dispersion, introducing 5% of ozone until the reaction is complete, and taking out the paper pulp;

step 2: preparing 2% pulp concentration of the thermal grinding mechanical pulp modified by ozone by using distilled water, respectively placing the pulp in a PFI pulping machine, and pulping until 9000 r;

and step 3: taking 20g of pulped raw materials to prepare paper pulp suspension with the concentration of 2%, adding 4% of foaming agent A and 25% of foaming agent B, uniformly mixing, adding into a fluffer, and generating foam under high-speed stirring.

And (5) injecting the wet foam into a mold, drying at a constant temperature, demolding, cutting, and then testing.

Example 2

A method for preparing ozone modified bagasse thermomechanical pulp and foam materials specifically comprises the following steps:

step 2: preparing certain pulp concentration by using distilled water for the thermomechanical pulp modified by ozone, placing the pulp in a PFI pulping machine, and pulping to 9000 r;

and step 3: taking 20g of pulped raw materials to prepare paper pulp suspension with the concentration of 3%, adding 4% of foaming agent A and 25% of foaming agent B, uniformly mixing, adding into a fluffer, and generating foam under high-speed stirring.

Example 3

(2) preparing certain pulp concentration by using distilled water for the thermomechanical pulp modified by ozone, placing the pulp in a PFI pulping machine, and pulping to 9000 r;

(3) taking 20g of pulped raw materials to prepare a paper pulp suspension with the concentration of 4%, adding 4% of foaming agent A and 25% of foaming agent B, uniformly mixing, adding into a fluffer, and generating foam under high-speed stirring.

Example 4

(1) Taking 50g of oven-dried bagasse thermomechanical pulp, adjusting the pulp concentration to 30% by using distilled water, placing the adjusted paper pulp in a stainless steel reaction tank for uniform dispersion, introducing 5% of ozone until the reaction is complete, and taking out the paper pulp;

(3) taking 20g of pulped raw materials to prepare paper pulp suspension with the concentration of 5%, adding 4% of foaming agent A and 25% of foaming agent B, uniformly mixing, adding into a fluffer, and generating foam under high-speed stirring.

And (4) injecting wet foam into the die, drying at constant temperature, demolding, cutting and testing.

Comparative example

(1) Preparing certain pulp concentration by using distilled water for thermal grinding mechanical pulp before ozone modification, respectively placing the pulp in a PFI pulping machine, and pulping to 9000 r;

(2) taking 20g of pulped raw materials to prepare paper pulp suspension with the concentration of 2%, adding 4% of foaming agent A and 25% of foaming agent B, uniformly mixing, adding into a fluffer, and generating foam under high-speed stirring. And (5) injecting the wet foam into a mold, drying at a constant temperature, demolding, cutting, and then testing.

The various examples and comparative examples were tested to obtain the modulus of elasticity of the foam as shown in table 1:

TABLE 1 mechanical Properties of the foams produced in the various examples and comparative examples

	Modulus of elasticity (kPa)
		Example 1	42.8
Example 2	47.5
		Example 3	67.9
Example 4	81.1
		Comparative example	19.9

As can be seen from Table 1, the elastic modulus of the foam produced after ozone modification is significantly higher than that of the foam produced without ozone modification; and it can also be seen that the higher the consistency of the pulp suspension, the better the modulus of elasticity of the foam produced.

The foregoing shows and describes the general principles, essential features, and advantages of the invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are merely illustrative of the principles of the invention, but that various changes and modifications may be made without departing from the spirit and scope of the invention, which fall within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims

1. A method for preparing a foam material based on ozone modified bagasse thermomechanical pulp is characterized by comprising the following steps:

step 2: introducing ozone into the adjusted mechanical pulp and reacting for a period of time;

and 4, step 4: preparing the pulped mechanical pulp into paper pulp suspension with certain concentration, adding a foaming agent A and a foaming agent B, and uniformly mixing;

and 5: stirring the slurry obtained in the step (4) for a period of time to obtain the foam material;

in step 4, the concentration of the pulp suspension is 2% -5%;

in the step 3, pulping by adopting a pulping machine, wherein the pulping revolution is 9000 r;

in step 4, blowing agent A and blowing agent B were used in amounts of 4% and 25%, respectively.