High-performance UV curing reactive thinner based on isolytic sorbitol

In a new study, scientists synthesized isolycol di (methyl) acrylates (ISD(M)A) as photo-curing reactive thinners.
UV curing coatings are particularly used in paper and eye lenses.
in UV curing coatings, active thinners are mainly used to regulate the viscosity of formulations and participate in UV curing
in
. However, obtaining refrative thinners with good dilution capability and good mechanical properties remains a huge challenge. In a new study, ISD(M)A) was designed and synthesized as a photo-curable refrogenic thinner. The photo polymerization dynamics of reactive thinners were studied using real-time infrared spectroscopy. The dilution capacity of reactive thinners in polyurethane acrylic acid (PUA) and epoxy acrylic acid (EA) was studied using a flow meter. Mix reactive thinners with PUA and EA to prepare a range of UV curable coatings and evaluate their thermal, mechanical and alkaline coating properties.
good dilution capability and high mechanical properties
results show that for PUA and EA, ISD(M)A exhibits dilution capabilities similar to those of commercially available reactive thinners. Adding 30% (weight) reduces formulation viscosity by three orders of magnitude, but the glass transition temperature (Tg) and pencil hardness of the ISDA-CN981 coating are 62.3 degrees C and 3H, respectively, higher than HDDA-CN981 (51.9 degrees C and 2 H). In addition, coatings containing ISD(M)A have higher energy storage mods and good impact performance. In this work, the good dilution ability of the active thinner and the high mechanical properties of the coating are realized. These bio-renewable, UV-curable isolytic acid-based reactive thinners show promising prospects in green photo-curing coatings.
1 . Introduction
UV








-cured coatings are considered energy-saving and green coatings, and have attracted extensive research and application interest due to their fast cur
ing speed. , mild curing conditions, low or zero volatile organic compound (VOC) emissions, and very good film performance. Light-curable coating formulations are usually made up of three parts: light-triggers, photosensitive resins and reactive thinners. Reactive thinners mainly dissolve and dilute resins, regulating the viscosity of the formula; It is also involved in curing resins to form cross-linked membranes (
6
,
7
). In general, single/dual-performance reactive diluents have better dilutability than multi-official reactive diluents, but single-d?orc reactive thinners can lead to lower cross-link density, which reduces the mechanical properties of the coating. Commercially available dual-functional reactive thinners such as 1,6-hethyl glycol diacrylates (HDDA) or tropyl glycol diacrylates (TPGDA) can also affect the mechanical strength of
coatings,
energy storage modules
and glass transition temperatures because of their flexible long fat chains (
8
,
9
). For these reasons, the use of commercial reactive thinners in coating formulations is limited. Therefore, it is still a huge challenge to obtain reserative thinners with good dilution capacity and good mechanical properties that lead to coatings after curing.
it has been reported that flexible fatty ether structures with good solubility with resins will result in a decrease in the mechanical properties of the material, while rigid ring structures can give the coating good mechanical properties . . .
10
. Therefore, the introduction of rigid rings into the fatty ether structure is expected to obtain refringing thinners with strong dilution capacity and mechanical properties that ensure the curing material. Isosanol (ISO) is glycol with a separate double-ring structure, which gives it a unique spatial
11
. These characteristics enable many ISO-based polymers to exhibit excellent mechanical and thermal properties . . .




. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . In addition, ISO is selected from glucose, which makes it one of the most promising renewable
15
,
16
. Currently, ISO has been
the development of
thermoplastics and
thermosolytic
polyesters.

,
,

polyurethane resins

18
) and epoxy
thermooensolated resins

20
). In addition, Reineke et al. Synthetic use of isothermalol pressure-sensitive adhesives, thus effectively improving the glass transition temperature and
thermal stability
materials (
21
,
22
). Webster et al. Synthesis of binary acids using ISO and
Malic acids
as crosslinkers for thermoo-solid resins has excellent thermal and mechanical properties .
23
. At the same time, the use of ISO synthesis
sumer
has been reported . . .
11
,
16
,
24
), but the exploration and development of high-performance bio-based photosensitive activity thinners using ISO's unique structure have not been reported.
in this article, we use isosol (ISO) and (methyl) acrylamide chlorine to synthesize ISD(M)A in one step. For comparison, hydroxyethyl ether (HQEE) is used to synthesize a pair of - benzene methyl ethyl (meth) acrylates (PHDE(M)A). We introduce special ring ether structures into target molecules for good dilution, and rigid ring structures give cross-linking networks with high hardness and modulus. At the same time, the potential image transformation maintains the flexibility of the interlinking network
23
. In order to systematically study the relationship between the structure and properties of reactive thinners, we analyzed dynamic thermal machinery and
streaching properties
photo-cured coatings prepared by mixing reactive thinners with PUA and EA. In addition, the basic properties of the coating are described in detail, including gloss, pencil hardness, pendulum hardness, shock resistance and adhesion.
2. The experimental section
2.1. The chemicals used in the material
are hydroquinone double (2-hydroxyethyl) ether (HQQE, Shanghai Aladdin Biochemical Technology Co., Ltd.), 1,4:3,6-double dianhydro-
d
Sorbitol (isosanol, ISO, Shanghai Vita Reagent Co., Ltd.), Acrylic chloride (AC, Shanghai Adamas Reagent Co., Ltd.), methyl acrylamide chloride (MAC, Shanghai Adamas Reagent Co., Ltd.), 2-Hydroxy-2-methylphenylphenyl acetone (1173, Changzhou Troon New Electronic Materials Co., Ltd.), 1,6 hexalycol glycerides, tripropylene glycol glycerides (HDDA, TPGDA) Jiangsu Kailin Ruiyang Chemical Co., Ltd.),
polyurethane
acrylic CN981 and epoxy acrylic CN104 (PUA, EA, Sartomer Co., Ltd.). )。 All other chemicals are from China Pharmaceutical Chemical Reagents Co., Ltd. (Shanghai, China). All chemicals are used as is unless otherwise stated.
2.2. Synthesis
2.2.1 . The synthetic
of methyl acrylic isomer (ISDMA)
, shown in Figure
1, adds ISO (7.31g, 0.05mol) and
dichloromethane
(DCM, 40mL) to a three-necked bottle with agitator and stirs in an ice bath (0-5 degrees C). Then slowly drip methyl acrylamide chlorine (13.58g, 0.15mmol) and add triacetylamide (12.14g, 0.12mol) to the system. After stirring at room temperature for 9 hours,
add
saturated NaHCO
3
aqueous solution to quench the reaction. White solids (triethylamine hydrochloride) are removed by filtration. Layer and then wash the organic phase twice
saturated
solution containing NaHCO 3. Then use the organic phase with waterless Na
2
SO
4
and concentrate
under reduced pressure. Using siliconecolumn chromatography,
uses ethyl acetate and petroleum ether to obtain the target product (ISDMA, 75% yield) in a ratio of 1:2. Use the same method to synthesize other materials and provide structural features in the support
.
the study was published
: Progress in Organic Coatings, volume 126, January 2019, pp. 162-167.