| Roof waterproofing,as an important part of building waterproofing,has always been the top priority of the industry.At present,the production technology and processing application of acrylic resin are developing rapidly.The synthetic adhesives,coatings,film,elastomers,water absorbent materials,building materials and so on are widely used in various industries.In this paper,acrylic resin and its monomer are used to make waterproof coatings for building roof,and their properties are studied.Then,according to the requirements and characteristics of roof waterproofing,the waterproofing coatings are improved to be applied in roof waterproofing engineering,so as to enrich the use of acrylic resin and increase the selectivity of roof waterproofing products.There are functional groups and unsaturated bonds on acrylic resin and acrylic monomers which can be condensated or copolymerized.Under the excitation of free radicals generated by redox reaction of initiator and promoter,they can be polymerized and crosslinked at room temperature to form a three-dimensional network of polymer coatings.The coatings are mainly C-shaped.H structure,not water affinity,molecular weight of about 20,000,excellent compactness,thus achieving the role of waterproof.In this paper,the performance index of acrylic waterproof coating is designed according to the environmental characteristics of roof waterproof and industry standard.According to the glass transition temperature of acrylic acid molecule,two kinds of acrylic prepolymer resins R1 and R2 with different degree of polymerization,two kinds of soft monomers,2-EHA and BMA,and hard monomers of methyl methacrylate(MMA),were selected to synthesize acrylic acid coating by changing the composition and amount.The flexibility and strength of the material were studied.In the redox system,BPO(benzoyl peroxide)and N-N-dimethylaniline were selected as initiators.Calcium carbonate powder was selected as filler and added to acrylic coatings in different proportions to study its effect on the mechanical properties of acrylic coatings.After that,the acrylic waterproof coatings with the best proportion of components were tested for their impermeability,low temperature flexibility,acid-alkali-salt resistance and solid content,and then applied to the roof waterproofing project after they were qualified to observe its long-term waterproofing effect.The final research results show that: 1.When the average tensile strength of the acrylic waterproof coating containing R1 resin reaches 5.848 MPa,its elongation at break can reach 301%,and its deformation recovery ability after failure is good.After low temperature treatment at-25 C and soaking in acid-alkali-salt solution,the tensile strength and elongation at break of the acrylic waterproof coating are over 85% and 90%,respectively.The test results are satisfactory.2.With the average tensile strength of 3.357 MPa,the elongation at break of acrylic waterproof coatings containing R 1 and R 2 mixed resins can reach 341%,but the deformation recovery ability after failure is general.However,the tensile strength retention rate of the acrylic waterproof coating is still better after low temperature treatment at-25 C and soaking in acid-alkali solution,which is over 80%,while the breaking elongation retention rate varies in size.The lowest is that the breaking elongation retention rate is only 53% after acid etching.Generally speaking,the test effect is general.3.Applying the acrylic waterproofing coating to a waterproofing project of a planted roof,after more than one year,no water leakage has occurred,and the effect of the project is good. |
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