Effects of Polyvinylamine and Polyvinyl alcohol on DOP Migration of PVC Film

Transcription

1 Applied Mechanics and Materials Online: ISSN: , Vols , pp doi: / Trans Tech Publications, Switzerland Effects of Polyvinylamine and Polyvinyl alcohol on DOP Migration of PVC Film Yupu Deng 1, a,#, Linxue Du 2,b,#,* Xihong Li 2,c, Xia Liu 2,d and Haijiao Liu 2,e 1 College of Materials Science and Techonlogy,Beijing Forestry University, Beijing,100083, PR China 2 Key Laboratory of Food Nutrition and Safety (Tianjin University of Science & Technology ),Ministry of Education, Tianjin, ,PR China a weile_du@126.com, b (correspondent)*dulinxue0608@163.com, c lixihong606@163.com, d liuxia831930@163.com, e liuhaijiao912@163.com # These authors contributed equally to this work. Keywords: PVC; DOP; polyvinylamine (PVAm); polyvinyl alcohol (PVA); migration. Abstract. The novel packaging was synthesised by coating polyvinyl chloride (PVC) film with Polyvinylamine/Polyvinyl alcohol (PVAm/PVA) mixture which can effectively inhibit the migration of DOP in this paper. The effect of PVAm/PVA mixture on inhibiting DOP migration was detected via extraction tests. The results showed that the novel packaging significantly reduced the migration rate of DOP compared with the control (PVC film). After 24h extracted by hexane 40% PVAm in mixture being coated on PVC had the lowest migration rate (6.20%) among the samples, while 7.60% is the migration rate of control sample. Tensile properties analysis indicated the elongation at break and tensile strength of samples coating PVAm/PVA higher than control sample. The thermogravimetric analysis demonstrated that the PVAm/PVA mixed solution can deduce thermogravimetric rate. Therefore, coating PVC with PVAm/PVA mixture is an effective approach to suppress the migration of DOP. Introduction Polyvinyl chloride (PVC) is one of the most important thermoplastics owing to its excellent balance between general properties and low costs.[1] PVC is used in the medical field extensively. To obtain the desired flexibility and durability, large amounts of plasticizers were added to PVC.[2] It is known that the plasticizer can migrate to the surface of the PVC matrix when it comes into contact with air, liquid and an absorbent solid material.[3] Plasticizer migration can cut down the functional performance of PVC, which is potentially harmful to the human health.[4] The plasticizer DOP, which will not be substituted in many fields for an extended period as the most commonly used plasticizer for PVC, is liquid and not chemically bound to the polymer. As the result that it can escape easily from the polymer matrix during storage or get extracted to the medium while in use.[5] Several approaches that refer to chemical modification or physical treatment on PVC have been developed to reduce DOP migration from PVC.[6] However, this study focuses on the coating PVAm/PVA mixture on the PVC surface to reduce DOP loss. The mixture of PVAm/PVA is a non-toxic organic compounds, which have a good viscosity. Due to the closely molecular structure of mixture, the small molecule is not easily to pass. As the result that it may suppress the DOP migration. In this paper, coating the PVAm/PVA mixture on PVC surface formed a layer membrane of high carbon dioxide and oxygen permeability, which will alleviate the DOP migration and thermogravimetric rate, improve the mechanical properties of the PVC matrix yet. All rights reserved. No part of contents of this paper may be reproduced or transmitted in any form or by any means without the written permission of Trans Tech Publications, (ID: , Pennsylvania State University, University Park, USA-21/02/16,04:51:40)

2 2994 Information Technology Applications in Industry II Experimental Materials and Methods Materials. PVC resin (trade name SG-3, k-value 72~71, 1350~1250) was supplied by Tianjin Chemical Plant, China. PVA (trade name 1799, degree of polymerization 500~2000, alcoholysis 75 ~99mo1%) was supplied by Shanghai Crystal Chemical Sales Co., Ltd., China. Polyacrylamide (weight (3~22) 10 6, degree of hydrolysis 10~15) was supplied by Shandong Sanfeng Group Co., Ltd., China. DOP (analytically pure) was supplied by Tianjin Letai Chemical Supermarket. Sample Preparation. The polyvinylamine solution were made as follows: NaOCl and NaOH solution were mixed and cooled in -12 ~ -15 ice-salt bath. Then 5% polyacrylamide solution joined in 1 h. The mixture react with NaOH solution for 1 h. Added the mixture to ice bath reacting for 10 h.the reaction solution was eluted by analytical grade anhydrous methanol until the ph of filtrate reach 7-8. The filtrate was dissolved in water and then neutralized with 6 mol/l hydrochloric acid until the ph of solution reach 2. The mixture was eluted by analytical grade anhydrous methanol again and then put it in a vacuum oven at 40 (-0.1 MPa) for 24 h until constant weight. The polyvinyl alcohol solution were made as follows: Polyvinyl alcohol solids were dissolved in water for 30 min, after that heated it to 80 in a heating rate of not more than 0.5 /min. The same time stirred it in a speed of 70 r/min~100 r/min until dissolved completely. Cooled it to room temperature. PVA and PVAm mixed in different proportions to 5%, 10%, 20% and 40% solutions (PVAm proportions). The solutions were coated on PVC films. Migration of DOP. Detected DOP extraction from the solvent according to GBZ/T [7] g of samples were set into stoppered erlenmeyer flasks (100 ml) and extracted with 20 ml of hexane at room temperature. The content of plasticizer was measured by High Performance Liquid Chromatography (HPLC), which was detected with Varian Prostar 210 LC pump and C18 column (50 mm 4.6 mm, 10µm). The injected volume was 20µL and the eluent was monitored at 224 nm. The mobile phase was the solution consisted of 90 phr methanol and 10 phr water mixture and pumped at a flow rate of 1.0 ml/min. Before injection, the extracts were diluted with hexane into a suitable concentration. The migration rate of the samples was calculated using the formula: migration rate(%)=w1/w2 100 (1) Where W1 is the weight of the extracted DOP tested by HPLC; W2, initial weight of the test specimen. Tensile Properties. The tensile properties were detected with a electronic tensile testingmachine (CMT4503, Shenzhen sans Materials Testing Co., Ltd, China) in the light of GB/T [8]. All the tests were done at a testing speed of 100 mm/min at room temperature. The samples were cut into dumbbell-shaped specimens. Five specimens from each sample type were tested and the average value was reported. Thermogravimetric analysis. The thermogravimetric analysis were performed refer to GB/T [9]. The samples which had been cut into 40 mm 60 mm were introduced into the desiccator for 4h. Recorded the weigh(m 0 ). The samples were set in an oven at (100 ± 2) for 6 h. Removed the samples from the oven to a desiccator for cooling to room temperature. Recorded the weigh(m). The thermogravimetric rate of the samples was calculated using the formula: (2) Where n is the thermogravimetric rate,%; m 0, the initial weight of the test specimen; m, the weight of samples after heating.

3 Applied Mechanics and Materials Vols Results and Discussion Migration of DOP. The migration rate is depicted in figure 1. The DOP migration rate increased with the time extend of PVC samples soaking in hexane. The samples coating with PVAm/PVA have the lower DOP migration rate than control sample significantly (p<0.05). The DOP migration rate decreased with the increasing of PVAm in PVAm/PVA mixed solution(fig.1(a)). After 24h extracted by hexane, 40% PVAm/PVA PVC sample had the lowest migration rate(5.27%) among the PVC samples, which reduced the DOP migration rate 62.82% compared with control sample(14.17%). However the 40% PVAm/PVA PVC sample lower only % than 5% PVAm/PVA PVC sample(8.00%)(fig.1(b)). The results show that coating PVAm/PVA mixed solution on PVC suface can inhibit the migration of DOP from PVC effectively in this study. (a) (b) Fig.1 (a)effect of PVAm/PVA mixture on the migration rate of DOP(%) of samples; (b) Effect of PVAm/PVA mixture on the migration rate of DOP(%) of samples after extracted 24h Tensile Properties. The tensile properties of the samples were shown in Figure 2. The tensile strength and elongation at break were both increased by the coating layers of PVAm/PVA. The elongation at break were similar among in the samples of coating 10%, 20% and 40% PVAm in mixture on PVC (271.5%, 271.6% and 275.2% respectively), which were higher 16.98%, 17.02% and 18.57% than the control sample(232.1%) respectively. The tensile strength of samples coating 20% and 40% PVAm in mixture on PVC (21.38 MPa and MPa) higher than the samples coating 5% and 10% PVAm in mixture on PVC (19.66 MPa and MPa), which both higher than the control sample(18.4mpa). The results show that the PVAm/PVA mixed solution can increase tensile strength and elongation at break of the PVC in this study. Fig.2 Effect of PVAm/PVA mixture on tensile properties of samples Thermogravimetric analysis. The thermogravimetric rate of the samples were shown in Figure 3. The thermogravimetric rate of the samples were decreased with increasing of PVAm. The sample of coating 40% PVAm in mixture on PVC have the lowest thermogravimetric rate (0.55%) in the

4 2996 Information Technology Applications in Industry II samples. The thermogravimetric rate of coating 5% PVAm in mixture on PVC(4.61%) lower 30.26% than the control sample(6.61%). The results showed that the PVAm/PVA mixed solution can decrease thermogravimetric rate of the PVC in this study. Fig.3 Effect of PVAm/PVA mixture on thermogravimetric rate of samples Conclusions 1. Coating PVAm/PVA mixed solution on the PVC can inhibit the migration of DOP. 2. The effect of coating a higher PVAm in PVAm/PVA mixed solution on PVC on inhibiting the migrate of DOP better. 3. Coating PVAm/PVA mixed solution on the PVC can increase the elongation at break and tensile strength of samples. 4. Coating PVAm/PVA mixed solution on the PVC can decrease the thermogravimetric rate of samples. Acknowledgements This work was financially supported by National High-New Technology Research Development Plan-863 (2012AA101703). References [1] Lederer, B. J Vinyl Addit Technol Vol. 4 (1998), p. 90. [2] Navarro, R.; Perrino, M. P.; Tardajos, M. G.; Reinecke, H. Macromolecules. Vol. 43 (2010), p [3] Mercer, A.; Castle, L.; Conyw, J.; Gilbert, J. Food Addit Contam. Vol. 7 (1990), p [4] Lan, O. W.; Wong, S. K. J Chromatogr A. Vol. 737 (1996), p [5] Huber, W. W.; Grasl-Kraupp, B.; Schulte-Herman, R. Crit Rev Toxicol. Vol. 26 (1996), p [6] Latini, G.; De Felice, C.; Verrotti, A. Reprod Toxicol. Vol. 19 (2004), p. 27. [7] GBZ/T Determination of toxic substances in the air of workplace aromatic esters (In Chinese). [8] GB/T Determination of Tensile Properties of Plastics(In Chinese). [9] GB/T Soft PVC calendered film and sheet (In Chinese).

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