A kind of grafted nano kenaf fiber whisker modified urea-formaldehyde resin adhesive and preparation method thereof

Abstract

The invention discloses a grafted nano ambary fiber crystal whisker modified urea formaldehyde resin adhesive and a preparation method thereof. The grafted nano ambary fiber crystal whisker modified urea formaldehyde resin adhesive is prepared from formaldehyde, urea, polyvinyl alcohol and a reaction enhancer, wherein the mole ratio of the formaldehyde to the urea is (1.1-0.95):1, and the addition amount of the polyvinyl alcohol is 0.1-0.8% of the total weight. The addition amount of the reaction enhancer is 0.1-3.0% of the total weight. The preparation method comprises the following steps: adding the reaction enhancer, adding the first batch of urea according to a mole ratio of (2.0-2.2):1, adding the second batch of urea according to the mole ratio of (1.4-1.2):1, and finally, adding the third batch of urea according to the mole ratio of (0.95-1.1):1. By using the formaldehyde and urea in a low mole ratio as the raw materials, the self-made acrylic acid grafted nano ambary fiber crystal whisker is added to increase the molecule branching degree and molecular weight of the resin, so that the low-mole-ratio urea formaldehyde resin has the advantages of low formaldehyde content, high adhesion strength and low cost.

Description

technical field [0001] The invention relates to an adhesive, in particular to a grafted nano-kenaf fiber whisker-modified urea-formaldehyde resin adhesive and a preparation method thereof, belonging to the field of adhesives. Background technique [0002] With the improvement of people's living standards and the continuous and stable development of construction, decoration, packaging and other industries, the output of wood-based panels in my country has grown rapidly. The total output of wood-based panels, plywood, furniture, and wood flooring has ranked first in the world for many years in a row. In 2013, the total output of wood-based panels in my country was 272 million m 3 , accounting for about 50% of the world's total production. Average production of 9m per ton of adhesive 3 According to the calculation of wood-based panels, the consumption of wood adhesives in my country in 2013 was about 30 million tons (solid content 50%), among which urea-formaldehyde resin an...

AI Technical Summary

Problems solved by technology

For example: 1) Although the use of low molar ratio modified urea-formaldehyde resin adhesives can effectively reduce the formaldehyde emission of wood-based panel products, the bonding strength of the products is often reduced, which cannot meet the requirements of use; and it can lead to prolonged curing time and reduced production efficiency; 2) Adding formaldehyde scavenger to urea-formaldehyde resin adhesives for wood-based panels can effectively reduce the release of free formaldehyde from wood-based panels, but it often reduces the bonding strength of wood-based panels at the same time; at the same time, the price of general formaldehyde scavenger is often much higher than that of urea-formaldehyde resin adhesives. Adding improves product cost and reduces product competitiveness; 3) Carry out post-processing to wood-based panels, as the invention patent application with publication number CN1526528 discloses a method for preparing E1 / EO grade environment-friendly wood-based panels using ammonia vacuum method. Manufacturing process; the utility model patent with publication number CN2394770 discloses a treatment device for reducing formaldehyde emission from wood-based panels. These post-processing methods not only make the manufacturing process of wood-based panels complicated, but also require huge investment in post-processing equipment and significantly increase production costs. ; 4) The use of other environmentally friendly adhesives, such as isocyanate adhesives, has led to a substantial increase in the production cost of wood-based panels and increased difficulty in the production process, which is difficult for enterprises and users to accept; the use of ordinary protein adhesives to prepare wood-based panels has low bonding strength and poor water resistance , easy to mold, poor sizing performance, easy to open glue for wood-based panels

In summary, although the above measures can effectively reduce the release of free formaldehyde from wood-based panels, they cannot completely solve the problem of formaldehyde release, or cannot be popularized due to reasons such as high production costs.

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