CS255392B1 - Process for preparing polybutyl acrylate by emulsion polymerization of butyl acrylate - Google Patents

Abstract

The purpose of the method for preparing polybutyl acrylate by emulsion polymerization is to improve the temperature control of polymerization and the quality of polybutyl acrylate latex. The above-mentioned purpose is achieved by polymerizing butyl acrylate under the action of an ammonium persulfate initiator, a hydroquinone inhibitor and an emulsifier of sodium salt of dodecylphenoxybenzenedisulfonic acid. The method for preparing polybutyl acrylate by emulsion polymerization is used in chemistry in the preparation of latex coatings and leather dispersion preparations.

Description

255392 3 4

The invention relates to a process for preparing polybutyl acrylate by emulsion polymerization of butyl acrylate.

Emulsion polymerization is used to prepare specialty polymers and polymer dispersions for barbecue applications in leather, textile, footwear and surface finishing applications. The emulsion polymerizations of acrylate monomers are characterized by their high polymerization rates, but this is disadvantageous for the difficulty in controlling and controlling exothermic polymerization processes, especially when preparing larger amounts of polymeric latexes. It is known that with increasing emulsifier concentration, the polymerization rate and the stability of the polymer emulsion [W. E. Smith, R. H. Ewart, J. Chem. Phys. 16, 592 (1948)]. However, in emulsion polymerization acrylate monomers, the increase in emulsifier concentration directly increases the polymerization rate with a negative impact on process temperature control and dispersion quality.

These disadvantages are largely discouraged by the preparation of polybutylacrylate emulsion polymerization of butyl acrylate by ammonium persulfate initiator and hydroehinone inhibitor, which consists in the addition of the dodecylphenoxybenzenedisulfonic acid salt as an emulsifier. The advantage of the proposed treatment of the preparation of polybutyl acrylate by the emulsion polymerization of butyl acrylate over the prior art is that the subject polymerization rate is lower with increasing the concentration of the anionic emulsifier of the sodium salt of dodecylphenoxybenzene disulfonic acid. As the emulsifier concentration increases, the retarding effect of the quinquinone increases and its inhibitory effect decreases. A further advantage is that low concentrations of the inhibitor can be used to control the polymerization rate, thereby reducing side reactions and effects during polymerization. The higher retardation efficiency of hydroquinone results from the interaction of the anionic emulsifier of the sodium salt of dodecylphenoxybenzene sulfonic acid. The interaction of the emulsifier with the hydroquinone results in increased inhibitor activity and its concentration at the surface of the latex particles in the vicinity of the reaction centers and a decrease in its concentration in the aqueous phase. Example 1

140 ml of distilled water, 97 g of butylacrylate and 0.45 g of sodium dodecylphenoxybenzene disulfonic acid (emulsifier, Dowfax 2A1) are charged into a three-necked 500 ml reaction flask equipped with a stirrer, a back-cooler, a nitrogen inlet and a continuous latex sampling device. After stirring for 30 minutes (400 rpm), 0.7775 g of ammonium persulfate (initiator) and 0.027 g of hydroquinone (inhibitor) are added sequentially at 70 ° C. During the polymerization, 1 ml of latex is collected to isolate the polymer and to the degree of conversion. The polymer is pre-dried at 20 degrees Celsius and is gelling in methanol acidified to pH = 2 with hydrochloric acid. The resulting polymer is washed with distilled water and dried at 20 ° C.

The dried polymer is dissolved in acetone and precipitated in methanol, the precipitated polymer is dried at 20 degrees Celsius for 24 hours and dried at 5 kPa pressure of 60 ° C for 8 hours. From the resultant polymer data obtained over a given time period, the time course of the polymerization inhibition period and the polymerization rate are calculated [D. Mikulá-šová: Macromolecular Chemistry, ES SVŠT, Bratislava, 1967, p. 108). The polymerization rate is 0.9% conversion per minute and the inhibition period is 10 minutes. Example 2

The procedure is as in Example 1 except that 0.72 g of dodecylphenoxybenzenesulfonic acid sodium salt is used as the emulsifier. The polymerization rate is 0.5. per minute and the inhibitory period is 9 minutes. Example 3

The procedure is as in Example 1 except that 1.8 g dodecylphenoxybenzene disulfonic acid sodium salt is used. The polymerization rate is 0.27pera. per minute and the inhibitory period is 8.5 minutes. Example 4

The procedure is as in Example 1 except that 5.36 g of sodium dodecylphenoxybenzene disulfonic acid is used as the emulsifier. The polymerization rate is 0.16per. per minute and the inhibitory period is 8 minutes.

To compare the effect of the sodium salt of dodecylphenoxybenzenedisulphonic acid emulsifier with the previously used emulsifiers, e.g. dodecylamine chloride, see the following example [F. A. Bovey, I. M. Kolt-hoff: J. Polym. Sci. 5, 569 (1950)]: Example 5

The procedure is as in Example 1, except that 4.94 g of dodecylamine chloride is used as the emulsifier, 0.29 g of potassium persulfate, 0.0044 g of hydroquinone, and styrene as monomer are used as the initiator. Polymerizes

Claims (1)

255392 5 β at 50 ° C. The polymerization rate is 1% conversion per minute and the inhibition period is 70 minutes. The process of preparing polybutyl acrylate by emulsion polymerization of butyl acrylate by the action of ammonium persulfate initiator and the invention can be found in a wide variety of applications in the preparation of coating lotions and leather preparations. DISCLOSURE OF THE INVENTION A hydroquinone inhibitor characterized in that sodium dodecylphenoxybenzenesulfonic acid is added as the emulator.