Process for the preparation of functionalized weather-resistant and slow-decaying geotextiles

Abstract

Processes for making weather resistant, slow-decaying, durable natural fiber/coir geotextiles produce geotextiles having flexibility, permeability, light weight and cost-effective characteristics. In this process an in situ chemical grafting using a mixture of Cashew Nut Shell Liquid and aminoalkyl trialkoxysilanes with cellulose was done followed by curing in presence of sunlight, UV light or heat. The developed product showed durability and strength more than that of natural fiber/fabric and retaining natural fiber/fabric/geotextiles characteristics. The geotextiles have delayed bio-deterioration having wider long-term end use/applications. This process of making durable geotextiles is eco-friendly and retains the desired characteristic.

Claims

1. A process for preparing a functionalized weather-resistant and slow-decaying geotextile fabric formed of coir fibers, the process comprising: (a) mixing 3-pentadecenyl phenols with aminoalkyl trialkoxysilanes in a ratio of from 1:1 to 3:1 (v/v) at a temperature of 30° C.±5° C. and humidity of 60% to 70% to obtain a mixture; (b) impregnating or coating the coir fibers of the geotextile fabric with the mixture as obtained in (a); and (c) curing the impregnated or coated coir fibers obtained in (b) under heat, UV, air, or sunlight to obtain the functionalized weather-resistant and slow-decaying geotextile fabric.

2. The process of claim 1, wherein the coir fibers are from Cocos nucifera and are in woven or non-woven form.

3. The process of claim 1, wherein the 3-pentadecenyl phenols are selected from the group consisting of cashew nut shell liquid, urushiol, cardanol, cardol, and anacardic acid.

4. The process of claim 1, wherein the aminoalkyl trialkoxysilanes are selected from the group consisting of aminopropyl triethoxysilane and 2-aminoethyl triethoxysilane.

5. The process of claim 1, wherein curing the impregnated or coated coir fibers comprises keeping the coir fibers at a temperature of 30° C.±5° C. and at a humidity of 60% to 70% for 3 days to 7 days.

6. The process of claim 1, wherein curing the impregnated or coated coir fibers comprises keeping the coir fibers in sunlight for a period of 6 hours to 12 hours, or in UV-light for a period of 3 hours to 5 hours, or in an air oven at a temperature from 60° C. to 90° C. for a period of 5 hours to 8 hours.

7. The process of claim 1, wherein curing the impregnated coir fibers comprises keeping the coir fibers at a temperature of 30° C.±5° C. for a period of 7 days to 10 days.

8. The process of claim 1, wherein (a) further comprises keeping the mixture at a temperature of 30° C.±5° C. at a humidity of 60% to 65% for 7 days to 10 days, and wherein (b) comprises coating the coir fibers of the geotextile fabric in the presence of 2% to 5% of excess 3-aminopropyl trimethoxysilane, and wherein (c) comprises curing the coated coir fibers for a period of 0.5 hours to 1.0 hours under UV light.

Description

DETAILED DESCRIPTION

(1) Embodiments of this disclosure explain, along with the representative experiments described herein below a process for the extension of lifetime of geotextiles prepared from coir and such cellulosic natural fibers by chemical grafting and curing for utilization as weather resistant and slow-decaying geotextiles. In situ surface modification or reactive coating of cellulosic hydroxyl groups by silyloxy pentadecenyl phenol derivatives formed by the reaction of CNSL with aminopropyl triethoxysilane and further curing in presence of sunlight, heat, or UV light optionally in presence of photo cross-linkers are explained as embodiment of the finding.

(2) The coir geotextile woven mats of GSM900 or GSM1200 were soaked with a solution of aminosilane derivatives and impregnated in situ with CNSL and then cured under ambient conditions by air drying, drying under sunlight by spreading. The curing was accelerated in the presence of UV light or in the presence of heat. CNSL and 3-aminopropyl trimethoxysilane were mixed at 3:1 ratio v/v and kept at a temperature of 30° C.±2° C. and a humidity of 60% to 65% for 7 to 10 days. Further, the mixture was coated on the geotextile fabric in presence of 2% to 5% 3-aminopropyl trimethoxysilane, which showed enhanced curing.

(3) These Geotextile samples showed retention or increase in tensile properties under standard Xenon arc test (D4355) compared to uncoated geotextile samples exhibiting weather-resistance. The standard degradation studies as per ASTM D5970, showed slow-decay than that of untreated geotextiles.

(4) Thus, the present disclosure provides geotextiles having improved longevity. Further, the geotextiles according to embodiments have lower water absorption. Also, the geotextiles exhibit less erosion or no erosion in strength under a standard Xenon arc test compared to untreated samples. Further, the geotextiles are weather resistant and termite resistant.

EXAMPLES

(5) The following examples are given by way of illustration only and therefore should not be construed to limit the scope of the present disclosure or the appended claims in any manner.

Example 1

(6) Cashew nut shell liquid (CNSL) was mixed with aminopropyl triethoxysilane (AS), in 3:1 volume ratio, impregnated on the woven coir geotextile [GT] mat of GSM740 roll, H2M5 Vycome (GT) using a two roll mill, and further cured by keeping under ambient conditions for 5 to 7 days.

Example 2

(7) Cardanol was mixed with AS, in 3:1 volume ratio, diluted to 30%, impregnated on the GT roll using a two-roll mill, and further dried by spreading under sunlight for 5 to 6 hours.

Example 3

(8) CNSL was mixed with AS, in 3:1 volume ratio, kept for 7 to 10 days under ambient conditions at sealed conditions from moisture and air, diluted with hexane to 30% solution, impregnated on the GT roll using a two roll mill, and further kept under UV light of 275 nm for 30 to 60 minutes.

Example 4

(9) CNSL was mixed with 2-aminoethyl triethoxysilane, in 3:1 volume ratio, kept for 7 to 10 days under ambient conditions at closed conditions, diluted with hexane to 30% solution, impregnated on the GT roll using a two roll mill, and further kept under sunlight for 2 to 4 hours.

Example 5

(10) GT was spray coated with 50% by volume of AS solution in acetone and was simultaneously reacted in situ in the presence of CNSL solution in acetone (20%-50% by weight), simultaneously impregnated using a two-roll mill, by simultaneous dozing of the 50% AS solution in acetone to the roller through a homogeneous sprinkler, and further cured by keeping under ambient conditions for 5 to 7 days.

Example 6

(11) GT was spray coated with 50% by volume of AS solution in acetone in the presence of CNSL solution in acetone (20% to 50% by weight), simultaneously dip coated using a two-roll mill, by simultaneous dozing of the 50% AS solution and benzophenone solution (0.5% to 2.0% by weight) in acetone to the roller through homogeneous sprinklers, and kept under UV light at 275 nm to 365 nm for 5 to 10 minutes.

(12) TABLE-US-00001 TABLE 1 Data on weathering studies of Geotextile (GT) as per ASTM D5970/16 Impact on longevity (Strength retained in outdoor exposure for Modifications via 6 months as measured by S. no. Control chemical treatments ASTM D5970) 1. GT roll GT roll + (Cardanol + AS, 3:1)  98% 2. GT roll GT roll + (Cardanol + AS, 1:1)  98% 3. GT roll GT roll + (Cardanol + AS, 3:1) + 30%  98% dilution + dried (5-6 hours) 4. GT roll GT roll + (Cardanol + AS, 1:1) + 30%  98% dilution + dried (5-6 hours) 5. GT roll GT roll + (CNSL + AS, 3:1) + 30% 100% C.sub.6H.sub.14 + UV (275 nm, 30-60 min.) 6. GT roll GT roll + (CNSL + AS, 1:1) + 30% 100% C.sub.6H.sub.14 + UV (275 nm, 30-60 min.) 7. GT roll GT roll + (CNSL + AS, 3:1) 7-8 days + 105% dilution 30% C.sub.6H.sub.14 8. GT roll GT roll + (CNSL + AS, 1:1) 7-8 days + 105% dilution 30% C.sub.6H.sub.14 9. GT roll GT roll + AS in Acetone 50% (v) + 105% CNSL in Acetone 20-50% (w) + curing 5-7 days 10. GT roll GT roll + AS solution in Acetone(v) + 102% CNSL in acetone 20-50% (w) in Acetone 11. Control Nil  55% 12. GT Roll GT Roll + CNSL in Acetone 20-50% +  80% dried in sunlight for 5-7 days