Bio-polyol composition and bio-polyurethane foam

Abstract

A bio-polyol composition and a bio-polyurethane foam are provided. The bio-polyol composition includes polyol, a surface-modified lignin, and a surfactant represented by formula 1. ##STR00001## wherein R is represented by C.sub.nH.sub.2n+1, n is an integer of 0 to 3; x/y is between 5 and 13; a is an integer of 1 to 100; b is an integer of 1 to 100.

Claims

1. A bio-polyol composition, comprising: a polyol; a surface-modified lignin; and a surfactant represented by formula 1 ##STR00004## wherein R is represented by C.sub.nH.sub.2n+1, n is an integer of 0 to 3; x/y is between 5 and 13; a is an integer of 1 to 100; b is an integer of 1 to 100, wherein the surface-modified lignin is formed by covering a surface of a lignin with a modifier or adsorbing the modifier to the surface of the lignin, a particle size of the surface-modified lignin is between 10 m and 60 m, the lignin is selected from the group consisting of sulfonate lignin, alkali lignin, or a combination thereof, and the modifier comprises alcohol, an epoxy resin, or a combination thereof having a hydroxyl group or an epoxy group.

2. The bio-polyol composition of claim 1, wherein the polyol comprises diol, triol, tetraol, or a combination thereof.

3. The bio-polyol composition of claim 1, wherein a weight ratio of the polyol to the surface-modified lignin is between 1:1 and 100:1.

4. The bio-polyol composition of claim 1, wherein a solubility of the surface-modified lignin is between 15 J.sup.0.5/cm.sup.1.5 and 40 J.sup.0.5/cm.sup.1.5.

5. The bio-polyol composition of claim 1, wherein a surface energy of the surface-modified lignin is between 25 mJ/m.sup.2 and 70 mJ/m.sup.2.

6. The bio-polyol composition of claim 1, wherein the surface-modified lignin is obtained by mixing the lignin and the modifier via a grinding and dispersing process to cover the surface of the lignin with the modifier.

7. The bio-polyol composition of claim 1, wherein based on a total weight of the bio-polyol composition, a weight ratio of the polyol to the surfactant is between 10:1 and 1000:1.

Description

DETAILED DESCRIPTION OF DISCLOSED EMBODIMENTS

(1) The bio-polyol composition of an embodiment of the disclosure includes polyol, a surface-modified lignin, and a surfactant. The bio-polyol composition can form a bio-polyurethane foam, and can have a foaming ratio about above 20 as a thermal insulating material. Each component of the bio-polyol composition of an embodiment of the disclosure is respectively described in detail below.

(2) The polyol of an embodiment of the disclosure is, for instance, diol, triol, tetraol, or a combination thereof, and examples thereof can include glycol, polypropylene glycol, dipropylene glycol, glycerin.

(3) The surface-modified lignin of an embodiment of the disclosure is uniformly dispersed in the polyol. The surface-modified lignin can mainly be formed via two methods. The first method includes forming the surface-modified lignin by covering the surface of a lignin with a modifier or adsorbing the modifier to the surface of the lignin. The lignin is, for instance, sulfonate lignin, alkali lignin, or a combination thereof. The modifier includes, for instance, alcohol, an epoxy resin, or a combination thereof having a hydroxyl group or an epoxy group. Examples of the modifier include, for instance, polyol, including ethylene glycol, polypropylene glycol (PPG), dipropylene glycol (DPG), glycerol, or a combination thereof. Using diol as an example, the two ends of the molecules thereof both have a hydroxyl group, and therefore the OH group at one end can be attached to the lignin surface to increase the dispersibility of the lignin, and the OH group at the other end can be subsequently reacted to form a foam.

(4) The second method of forming the surface-modified lignin of an embodiment of the disclosure includes covering the surface of lignin using a modifier by mixing lignin and the modifier via a grinding and dispersing process to obtain the surface-modified lignin. The lignin and the modifier are as described above and are not repeated herein. Via the grinding and dispersing process, the particle size of the lignin can be reduced and the modifier can effectively cover the surface of the lignin at the same time so that the surface energy of the lignin can be reduced. The surface energy of the surface-modified lignin can be, for instance, between 25 mJ/m.sup.2 and 70 mJ/m.sup.2.

(5) In an embodiment of the disclosure, the particle size of the surface-modified lignin can be between 1 m and 100 m, such as between 10 m and 60 m, or between, for instance, 10 m and 30 m. If the particle size exceeds 100 m, then the lignin is readily aggregate. Moreover, if the particle size is less than 1 m, then the viscosity of the lignin is too high such that the issue of uneven mixing occurs in the subsequent forming of a foam. The grinding and dispersing treatment can be a bead mill treatment, a milling treatment, or a combination thereof. The duration of the grinding and dispersing treatment can be between 5 minutes and 240 minutes. If the grinding time exceeds 240 minutes, then the particle size of the lignin is too small. Moreover, if the grinding time is less than 5 minutes, then the particle size of the lignin is too large.

(6) The solubility of the surface-modified lignin of an embodiment of the disclosure is, for instance, between 15 J.sup.0.5/cm.sup.1.5 and 40 J.sup.0.5/cm.sup.1.5, and the particle size thereof is, for instance, between 1 m and 100 m. Moreover, in the bio-polyol composition of an embodiment of the disclosure, the weight ratio of polyol to the surface-modified lignin is, for instance, between 1:1 and 100:1, such as between 1:1 and 10:1, or between, for instance, 1:1 and 2:1.

(7) The surfactant of an embodiment of the disclosure has the structure shown in formula 1,

(8) ##STR00003##
wherein R is represented by C.sub.nH.sub.2n+1, n is an integer of 0 to 3; x/y is between 5 and 13; a is an integer of 1 to 100; b is an integer of 1 to 100. In the bio-polyol composition of an embodiment of the disclosure, the weight ratio of the polyol and the surfactant is, for instance, between 10:1 and 1000:1. By adjusting the value of x/y, the foam body of the foam can be stable, and the size and uniformity of the aperture of the cell can be controlled, such that the bio-polyurethane foam formed by the bio-polyol composition of an embodiment of the disclosure can have a relatively high foaming ratio (such as above 20), and the aperture of the cell can be controlled to be between 400 m and 2100 m (such as between 400 m and 600 m), and the foam can have good compressive strength and low thermal conductivity as a thermal insulating material. If the value of x/y is less than 5, then the foaming ratio is too low, such that the resulting foaming material cannot have good thermal insulating effect.

(9) In an embodiment of the disclosure, the bio-polyol composition includes 100 parts by weight of polyol, 50 parts by weight to 100 parts by weight of the surface-modified lignin, and 0.1 parts by weight to 10 parts by weight of a surfactant.

(10) In an embodiment of the disclosure, the bio-polyol composition can form a foam composition with diisocyanate, and a foaming treatment is performed on the foam composition to form the bio-polyurethane foam of an embodiment of the disclosure. The foaming treatment is, for instance, mechanical foaming, physical foaming, chemical foaming, or supercritical foaming. In the foam composition, the weight ratio of the bio-polyol composition to the diisocyanate is, for instance, between 0.5:1 and 2:1. The diisocyanate is, for instance, aliphatic diisocyanate, aromatic diisocyanate, or a combination thereof. With different foaming treatments, the foam composition can further contain, for instance, a foaming agent or a catalyst. In the foam composition, the weight ratio of the bio-polyol composition to the catalyst is, for instance, between 10:1 and 10000:1, and the weight ratio of the bio-polyol composition to the foaming agent is, for instance, between 1:1 and 1000:1, or between, for instance, 1:1 and 100:1. The catalyst is, for instance, a metal salt catalyst, an amine catalyst, or a combination thereof. The foaming agent is, for instance, water, cyclopentane, dichloromethane, acetone, methyl ethyl ketone, n-hexane, n-pentane, or a combination thereof.

(11) The bio-polyurethane foam formed by the foaming treatment of an embodiment of the disclosure contains the surface-modified lignin and the surfactant represented by formula 1. The particle size of the surface-modified lignin can be between 1 m and 100 m, such as between 10 m and 60 m, or between, for instance, 10 m and 30 m. Based on a total weight of the bio-polyurethane foam, the amount of the surface-modified lignin is, for instance, between 5% and 30%.

(12) In the following, the characteristics of the bio-polyol composition of the disclosure and the bio-polyurethane foam formed thereby are described with example 1 to example 4 and comparative example 1 to comparative example 3. The resulting foam is tested for compressive strength, foaming ratio, and thermal conductivity, and the results are shown in Table 1.

Example 1

(13) 45 g of alkali-soluble lignin was added in 82.1 g of polypropylene glycol (PPG400), and after dispersing using a grinding and dispersing machine for 30 minutes, 2.4 g of surfactant A (having the structure represented by formula 1, x/y=12.02), 0.11 g of a catalyst (mixture of tin catalyst and amine catalyst), and 4 g of a foaming agent (water) were added, and the components were uniformly mixed. Next, 137 g of polymeric methylene diphenyl diisocyanate (PMDI) was added to perform foaming.

Example 2

(14) Except that surfactant B (having the structure represented by formula 1, x/y=8.98) was used to replace surfactant A, the same production method as example 1 was used.

Example 3

(15) Except that surfactant C (having the structure represented by formula 1, x/y=5.64) was used to replace surfactant A, the same production method as example 1 was used.

Example 4

(16) Except that surfactant D (having the structure represented by formula 1, x/y=5.37) was used to replace surfactant A, the same production method as example 1 was used.

Comparative Example 1

(17) Except that 127.1 g of PPG400 was used and no lignin was added, the same production method as example 1 was used.

Comparative Example 2

(18) Except that surfactant F (having the structure represented by formula 1, x/y=2.74) was used to replace surfactant A, the same production method as example 1 was used.

Comparative Example 3

(19) Except that surfactant G (having the structure represented by formula 1, x/y=2.14) was used to replace surfactant A, the same production method as example 1 was used.

(20) TABLE-US-00001 TABLE 1 Compressive Thermal Aperture of cell Foaming strength conductivity (m) ratio (kgf/cm.sup.2) (W/mK) Example 1 400 to 600 20.48 2.15 0.032 Example 2 450 to 600 20.38 2.04 0.032 Example 3 1500 to 1800 20.96 1.35 0.037 Example 4 900 to 2100 20.37 1.38 0.036 Comparative 400 to 600 22.08 1.59 0.03 example 1 Comparative 400 to 600 7.65 4.64 0.048 example 2 Comparative 750 to 1300 5.78 0.048 example 3

(21) It can be clearly seen from Table 1 that:

(22) When the foam is used as a thermal insulating material, the foaming ratio needs to be greater than 20 to lower the thermal conductivity to about 0.035 W/mK or less. Neither comparative example 2 nor comparative example 3 reach industry standard, and when compared to the foam of comparative examples 2 and 3 (value of x/y less than 5), the foam of example 1 to example 4 (value of x/y between 5 and 13) all have higher foaming ratio and lower thermal conductivity, and therefore the foam of example 1 to example 4 can have better thermal insulating effect.

(23) Moreover, in comparison to the foam of comparative example 1 (without lignin), the foam of example 1 and example 2 (containing both lignin and the surfactant having the structure represented by formula 1) can have better compressive strength when having a closer foaming ratio.

(24) It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the disclosed embodiments without departing from the scope or spirit of the disclosure. In view of the foregoing, it is intended that the disclosure cover modifications and variations of this disclosure provided they fall within the scope of the following claims and their equivalents.