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2022-08-13
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Some plant-based polymer resins used in outdoor wood coatings and furniture coatings

some plant-based polymer resins used in outdoor wood coatings and modified plastics in China's plastic machinery industry

October 17, 2018

Author: what are the biomedical ophthalmic materials of TIJS nabuurs and Maud kastelijn? Blue DSM coating resins company

this paper introduces stone It is a plant-based substitute for monomers such as oil-based (meth) acrylate. At least in terms of performance, the performance of outdoor wood coatings and furniture coatings (the raw materials used contain 40% plant base) is equivalent to that of petroleum based control formula

polymer base containing (methyl) allyl propionate as raw material has been used in the paint market for a long time in China. Due to the increasing depletion of natural resources on the earth and the aggravation of climate change, the paint industry is also under greater pressure, and it is necessary to find substitutes with plant-based raw materials. Since the beginning of the 20th century, there have been many studies on renewable alternatives to current paint polymers. Most studies use vegetable oil or sugar, and modify the wood structure to obtain lignin. Although the resulting polymer has many advantages, it still cannot become a substitute for modern coatings in the indoor furniture or outdoor industrial woodwork market

it has been suggested that a variety of methods should be used to produce plant-based polymer substrates that can actually provide coatings (part) to prepare renewable monomers, but so far there is no news about the commercialization of such plant-based substrates

in this paper, you will know that it is feasible to produce some plant-based polymer resins for industrial coatings and wood coatings through lotion polymerization. This paper will also compare some coatings produced by some plant-based polymers with products prepared from petrochemical raw materials

the polymer synthesis in this paper is limited to lotion polymerization. The detailed introduction of this technology has also been published before

technical background and commercial situation

using plant-based materials to replace petroleum based materials for resin synthesis, it is necessary to find suitable commercialized plant-based monomers, but at present, common acrylate and methacrylate monomers cannot be obtained from renewable resources

in the past decade, various methods of using plant-based resources to produce acrylic acid and methacrylic acid have been developed, for example, 3-hydroxypropionic acid or glycerol can be used to prepare acrylic acid

synthetic gas (mainly composed of a mixture of hydrogen and carbon monoxide) can be used to prepare methacrylic acid. At present, this synthetic gas is derived from petroleum based resources, and obviously can also be obtained from renewable resources

however, plant-based acrylic acid and methacrylic acid have not been commercially applied at present, and only other monomer materials can be used. In free radical polymerization, not all double bonds are reactive, but the monomers actually used in lotion polymerization need to conform to the general structure shown in Figure 1

for example, if it is acrylate and methacrylate monomer, X and y are oxygen, while R1 is hydrogen or methyl, it is expected that there will be five different plant-based structures, which are not only reactive in free radical polymerization, but also have the possibility of commercial application

overview of results

- at present, several plant-based alternatives to petrochemical methacrylate monomers have been achieved. Among them, the most likely ones include itaconic acid diester and methacrylate monomer prepared with plant-based alcohols

- other plant-based monomers have the problem of too slow or too fast activity, or have not been commercially available

- self crosslinking outdoor wood coatings and two-component isocyanate crosslinked furniture coatings are prepared from substrates containing 40% plant-based carbon. After the preliminary test of this kind of coating, it is found that its performance is equivalent to that of the petroleum based control formula

- at present, polymer matrix containing about 40% plant-based content can be obtained (based on total carbon content). In the next five years, it is expected to obtain new base materials with higher plant-based content

Table 1 exterior wall varnish and paint formula based on self crosslinking base material

varnish formula paint formula base material *70.655.6 water 18.65.3 * * diethylene glycol butyl ether 2.22.5thixol 53l (ratio to water 1:10) 725daprodf75800.60.4borchigel L75 (ratio to water 1:1) 0.80.6disperbyk2015

1.5**tego foamex 810

0.3 * * Kronos 2190

24 * * ammonia (25%) *******The solid content is 44%

* * the coating slurry is partially premixed

* * * the pH value is increased to 8.9

the plant-based substitute in methacrylic acid vinegar

the first practical substitute introduced in this paper uses plant-based alcohols in methacrylate monomers (see R2 in Figure 1), forming some plant-based raw material units. From the perspective of polymerization activity, these monomers can be directly added to the existing monomers, which is a quite practical method

in this way, another advantage of these monomers in polymer performance is well understood. Unfortunately, not all alcohols used in (meth) acrylic monomers can be obtained from renewable resources. If this method is used, other factors need to be considered, because the renewable content may be limited according to the number of carbon atoms in alcohols

for acrylic monomers obtained from plant-based alcohols, the biological base concentration (calculated according to carbon atoms) ranges from 25% (methyl) to 73% (octyl). In the case of methacrylate, the range is 20% - 67%. From this point of view, long-chain alcohols are more likely to produce coatings with reasonable renewable carbon concentration

the existing commercial solutions use acrylic monomers containing ethanol or n-butanol. In the references, other schemes, such as 2-octyl acrylate and isobornyl methacrylate, are also introduced. In particular, 2-octyl acrylate is very interesting. It has a high renewable content and seems to be able to easily replace the commonly used 2-ethylhexyl acrylate

Figure 1 general structure of monomers that can be used for free radical polymerization

Figure 2 structure of methylene butyrolactone

itaconic acid: promising, but there are still problems

the second plant-based substitute introduced in this paper is the dialkyl ester of itaconic acid (DRI). Wherein, R1 in Figure 1 is ch2c (0) 0r2 group, and X and y are oxygen. Since the 1960s, itaconic acid has been produced by fermentation. At present, sugar fermentation is the most suitable production method

as mentioned above, plant-based substitutes made from the most common alcohol residues are usually expensive. Then, the use of petroleum based alcohols will obviously reduce the plant-based content in dri monomers. When methyl ester is replaced by octyl ester, the content of bio base in dri monomer will be reduced from 71% to 24%

while DRI monomers containing plant-based alcohols can obviously produce 100% bio renewable monomers, but the difference between bridging and foaming time cannot be too large. Among them, 100% plant-based itaconic acid monomers such as dimethyl itaconic acid (DMI) and dibutyl itaconic acid (0bi) have been commercially applied and sold

using itaconate in the base material has two advantages: glass transition temperature (see Cowie et al.) and water solubility can be comparable with methacrylate containing the same alcohol

there are also many problems when itaconate is used in lotion polymerization. For example, the R1 group is too large, resulting in low activity. The chain growth rate constant of dialkyl itaconate is usually controlled at 5~10 l/mole S

it can be seen that it is difficult to prepare itaconate dialkyl ester functional copolymers with high DRI monomer concentration, high monomer conversion and high molecular weight. However, it can be improved by controlling polymerization conditions and optimizing polymerization process

Table 2 performance comparison of outdoor wood coatings (including resins made of all petrochemical based monomers or some plant-based monomers)

varnish formula paint formula

petroleum based plant cornerstone oil-based plant-based resin contains the most biomass (based on carbon content) 0% 40% 0% 40% early water resistance (4h) *2/53/5

early adhesion resistance (wet film thickness 500mu) *4433 elongation at break (110mu) toughness (MPA) 8127.57.5 impact resistance (n) -RT/7 ° C8/67/68/79/7 outdoor exposure (24m)

good good QUV en (2016 h)

good Gardner (357 cycles)

good good good *0-poor 5-excellent

crotonate and malonate: the emergence of a pair of contradictions

crotonate provides a third plant-based solution for biologically based monomers. For example, crotonic acid can be obtained from plant-based raw materials through the thermal decomposition of 3-hydroxybutyrate. Although its structure is very similar to that of methacrylate, it cannot be fully and efficiently copolymerized to form copolymers, so it can be excluded

the fourth kind of plant-based monomer is methylene malonate diester. R1 in Figure 1 is C (0) 0r2 group, and malonic acid can be generated by using renewable components (such as 3-hydroxypropionic acid). As early as the 1940s, Bachman and others have introduced the synthesis of methylene malonate

because the double bond of methylene malonate can realize secondary activation, these monomers have high reactivity, especially in anionic polymerization. Their reactivity in anionic polymerization is also quite positive, and even when they are in contact with non acidic water, these monomers will spontaneously polymerize. Therefore, it is unrealistic to use methylene malonate in lotion polymerization

at present, no feasible scheme has been found in the future.

the last type of potential plant-based monomer is shown in Figure 2 α- Methylene butyrolactone structure. The introduction of this monomer can be traced back to 1947, and its free radical polymerization was also introduced in 1979, and also introduced in the same year α- Copolymerization of methylene butyrolactone with methyl methacrylate, styrene, acrylamide and acrylonitrile

α- The polymerization rate of methylene butyrolactone is very fast, which is very conducive to the formation of film, for example, when T9 reaches 19S C. Unfortunately, the product has not yet been sold on the market

to sum up, the use of itaconate and (meth) acrylate is the most ideal scheme to generate some bio based copolymers at present

Table 3 varnish formula of indoor two-component NCO curing paint. See Table 4 for the properties of cross-linked coating

varnish formula base *100 water 4.4 diethylene glycol butyl ether 8rsdiasolve75292tego Airex 902w • cotton stick cylinder length measuring machine water-based defoamer 0.6cosrexbrilop- (proportion to water 1:1) water-based thickening and leveling agent 1bayhyduf2655- (701% MPa solution) water-based Pu curing agent 18.1 water 10* use table 4 two-component isocyanate crosslinked indoor furniture paint (containing all petroleum based monomers or some plant-based monomers base material) at 40% solid content Film performance

biomass content in petroleum based plant base material (calculated by carbon content) 0%40% gloss (20 °/60 °)

58/8064/89 chemical resistance * ethanol 1h55 red wine 6H4 ~ 55 coffee 16h55 water 16h55 mustard 6h33 onion juice 6h3 ~ 43 ~ 4 * 0-poor 5-excellent self crosslinking outdoor coating has excellent performance

in this part, we compared the film-forming performance of some plant-based resins with that of petroleum based monomers, In addition, the single component self crosslinking coating for outdoor wood and the two-component NCO curing coating for indoor furniture were also compared

first of all, we can see that the resin containing ketone functional groups of one component self crosslinking coating can react with polyhydrazide during film formation. One

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