Effect of Plasticizers on the Properties of Silane-Modified Polyether Waterproof Coatings

Silane-modified polyether waterproof coating is a new type of environmentally friendly waterproof coating based on silane-modified polyether. Plasticizers are used in a wide range of fields, and are usually added to plastics, resins or elastomers to improve their processability, plasticity, flexibility, stretchability and other properties. Adding plasticizers to waterproof coatings can mainly be used to reduce the viscosity of the coatings and make them have excellent construction performance; in addition, the addition of plasticizers will also have a certain degree of impact on other properties of waterproof coatings. This study focuses on the investigation of diisononyl phthalate (DINP), dipropylheptyl phthalate (DPHP), didecyl phthalate (DIDP), cyclohexane-1,2-di Effect of plasticizers such as isononyl formate (DINCH), polyether diol and polyether triol on the properties of silane-modified polyether waterproof coatings.

Add the calculated amount of silane-modified polyether, plasticizer, filler and auxiliary agent into the dynamic mixer, stir in vacuum for 2 h, and finally pack the prepared silane-modified polyether waterproof coating in a In a closed container, test its performance according to the requirements of relevant standards.

01

Compatibility Analysis of Plasticizer and Silane Modified Polyether

The silane-modified polyether was mixed with 20% of the total formula of DINP, DINCH, DPHP, polyether diol, polyether triol and DIDP, and then left to stand for 7 days without stratification or turbidity. The silane-modified polyether without plasticizer was first cured under standard conditions for 7 days, and then the cured product was soaked in the above six plasticizers for 7 days, and the mass was weighed. The specific results are shown in Table 1. After soaking silane-modified polyether cured product in DINP, DINCH, DPHP and DIDP, there will be obvious swelling, more mass increase, greater mass change rate, and better compatibility; soaking in polyether glycol, polyether three The mass increase after polyalcohol is less, but because the hydroxyl group of polyether diol and polyether triol can react with the alkoxyl group of silane-modified polyether, thereby improving its compatibility, it is not easy to migrate. However, the amount of plasticizer also needs to be controlled within a certain range.

02

Effect of Plasticizer on Mechanical Properties of Silane Modified Polyether Waterproof Coatings

The influence of plasticizers on the mechanical properties of silane-modified polyether waterproof coatings is shown in Table 2. The addition of plasticizer can not only increase the elongation at break of the waterproof coating, but also improve its toughness and flexibility, and reduce its viscosity. The tensile strength of the silane-modified polyether waterproof coating prepared by adding polyether triol is the highest, and the influence of the other five plasticizers on its tensile strength is basically the same. The elongation at break of the silane-modified polyether waterproof coating prepared by adding polyether diol reached 639%, which was significantly higher than the other five plasticizers.

03

Effect of Plasticizer on Adhesive Properties of Silane Modified Polyether Waterproof Coatings

The effect of plasticizers on the adhesion properties of silane-modified polyether waterproof coatings is shown in Table 3. The silane-modified polyether waterproof coating prepared by adding polyether diol and polyether triol has the highest bond strength before and after immersion, and the failure mode is 100% cohesive failure; the addition of DINP, DINCH, DPHP and DIDP prepared The bond strength of silane-modified polyether waterproof coatings is not much different, and they all show different degrees of interface damage. The damage degree before immersion is 10%~15%, and the bond strength decreases by more than 50% after immersion, and the damage form is also 50%. cohesive failure.

04

Effect of Plasticizer on Aging Resistance of Silane Modified Polyether Waterproof Coatings

The effects of plasticizers on the aging resistance of silane-modified polyether waterproof coatings are shown in Table 4. The six plasticizers selected in this study have varying degrees of influence on the aging resistance of silane-modified polyether waterproof coatings, but the tensile strength retention rates are all in the range of 70% to 150%, and the elongation at break is greater than 400%. The silane-modified polyether waterproof coating prepared by adding DINP, DINCH and DPHP has better aging resistance, more stable mechanical properties, the strength retention rate is in the range of 90% to 110%, and the elongation at break is greater than 450%. The obtained silane-modified polyether waterproof coating has relatively poor aging resistance, the strength retention rate is lower than 90%, and the elongation at break is lower than 450%. The tensile strength of the silane-modified polyether waterproof coating prepared from polyether diol and polyether triol increases after heat treatment, alkali treatment and acid treatment.

05

Effect of Plasticizer on Waterproof Performance of Silane Modified Polyether Waterproof Coating

Different types of plasticizers have basically no effect on the impermeability of the silane-modified polyether waterproof coating, and all of them can pass the impermeability test. The silane-modified polyether waterproof coating prepared by adding polyether diol has the best waterproof performance and the lowest water absorption. After the silane-modified polyether waterproof coating prepared by adding polyether trihydric alcohol is soaked in water, the water absorption rate decreases instead, and the diaphragm separates oil.

06

Effect of plasticizer on storage performance of silane-modified polyether waterproof coating

The six plasticizers used in this study have basically no effect on the appearance and surface dry time of silane-modified polyether waterproof coatings. The initial viscosity of the silane-modified polyether waterproof coatings prepared by adding DINP, DINCH, DPHP and DIDP was slightly lower than that of the silane-modified polyether waterproof coatings prepared by adding polyether diols and polyether triols. After heating and accelerated aging, the viscosity increase of silane-modified polyether waterproof coatings prepared by adding DINP, DINCH, DPHP and DIDP was relatively small, and the viscosity of silane-modified polyether waterproof coatings prepared by adding polyether diols and polyether triols Viscosity increases relatively more.

In this study, a new type of environmentally friendly waterproof coating was prepared using silane-modified polyether as the base polymer, with fillers and additives, and tested DINP, DINCH, DPHP, polyether diol, polyether triol, DIDP The impact of other plasticizers on its performance, the results are as follows:

1) The test shows that DINP, DINCH, DPHP, polyether diol, polyether triol and DIDP have good compatibility with silane-modified polyether. The silane-modified polyether waterproof coating prepared by adding polyether diol and polyether triol has relatively better mechanical properties and bonding properties, and the silane-modified polyether waterproof coating prepared by adding polyether diol has the best waterproof performance. good.

2) The aging resistance of the silane-modified polyether waterproof coatings prepared by 6 kinds of plasticizers in this research meet the requirements of use, but the aging resistance of the silane-modified polyether waterproof coatings prepared by DINP, DINCH and DPHP, The mechanical properties and storage stability are better, the strength retention rate is maintained in the range of 90% to 110%, the elongation at break is greater than 450%, and the viscosity after accelerated aging is around 9 000 mPa·s.