CN-121537462-B - Green bio-based flame-retardant polyvinyl alcohol composite material capable of being melt-processed

Abstract

The invention belongs to the field of flame-retardant materials, and discloses a melt-processable green bio-based flame-retardant polyvinyl alcohol composite material, which is characterized in that cytidine-5' -phosphate and cardanol are taken as raw materials to synthesize a high-thermal-stability green bio-based flame retardant CADCM, and the high-thermal-stability green bio-based flame retardant is compounded into a polyvinyl alcohol (PVA) base material through a high-efficiency melt-processing technology to prepare a target composite material. The method can realize the remarkable improvement of the flame retardant property and the mechanical property of the PVA material on the premise of ensuring the good melt processability of the PVA material, and the bio-based flame retardant PVA composite material has the advantages of environmental protection, processing suitability and comprehensive performance, and provides a high-efficiency and feasible technical path and innovation thinking for widening the practical application scenes of the PVA material in the fields of functional packaging films, environmental-friendly plastic products and the like.

Inventors

• XU WENZONG
• Xuan Ziyi

Assignees

• 安徽建筑大学

Dates

Publication Date

20260512

Application Date

20260121

Claims (4)

1. 1. A green bio-based flame retardant is characterized in that the flame retardant is pentadecyl benzoxazinyl cytidine-5 '-phosphate generated by reacting cytidine-5' -phosphate with cardanol, which is shown as CADCM, and the structural formula of CADCM is shown as follows: 。
2. 2. A method of preparing the green bio-based flame retardant of claim 1, comprising the steps of: Weighing 0.01 mol of cardanol, adding 140-160 mL of absolute ethyl alcohol, and stirring for dissolution to obtain a cardanol solution; weighing 0.01-mol '-cytidine-5' -phosphoric acid, adding 70-90 mL of deionized water, placing in a 50-60 ℃ oil bath, stirring until the solution is dissolved, adding 0.02-mol formaldehyde, continuously stirring for 0.2-0.5 h, adding the cardanol solution, heating the oil bath to 110-120 ℃ and continuously stirring for reacting for 4-4.5 h, cooling to room temperature after the reaction is finished, filtering, collecting a product, washing by adopting a mixed solution of absolute ethyl alcohol and deionized water, and finally placing in a 50-60 ℃ oven for drying for 20-24 h, thereby obtaining the product CADCM.
3. 3. A melt-processable green bio-based flame-retardant polyvinyl alcohol composite material is characterized in that the composite material is prepared by adding the green bio-based flame retardant according to claim 1 into a polyvinyl alcohol base material in a melt processing mode and is recorded as CADCM/PVA material, wherein in the composite material, the mass percent of the polyvinyl alcohol base material is 85% -92.5%, and the mass percent of CADCM is 15% -7.5%; The polyvinyl alcohol base stock comprises, by weight, 77.5-78.5 parts of polyvinyl alcohol, 10.5-11.5 parts of glycerin, 6.5-7.5 parts of ethylene glycol, 0.45-0.55 part of an antioxidant 1010, 0.45-0.55 part of zinc stearate, 0.45-0.55 part of calcium stearate and 2.45-2.55 parts of caprolactam.
4. 4. A method of preparing the melt-processible green bio-based flame retardant polyvinyl alcohol composite material of claim 3, comprising the steps of: step 1, taking polyvinyl alcohol, glycerol, ethylene glycol, an antioxidant 1010, zinc stearate, calcium stearate and caprolactam, and pouring the mixture into a high-speed mixer to mix for 10-15 min to prepare a polyvinyl alcohol base material; Step 2, uniformly mixing a polyvinyl alcohol base material and a flame retardant CADCM, adding the mixture into an internal mixer heated to 165-170 ℃ for mixing for 2-3 min, and taking out a mixed product; And step 3, placing the mixed product in a flat vulcanizing machine, carrying out hot pressing treatment for 1-2 min at 170-175 ℃ and forming into a sheet sample to obtain CADCM/PVA material.

Description

Green bio-based flame-retardant polyvinyl alcohol composite material capable of being melt-processed Technical Field The invention belongs to the field of flame-retardant materials, and particularly relates to a melt-processable green bio-based flame-retardant polyvinyl alcohol composite material. Background Under the push of the green sustainable development concept, scientific researchers are actively exploring and applying new environment-friendly polymer materials. Among them, polyvinyl alcohol (PVA) has a great application potential in the fields of functional packaging films, environment-friendly plastic products and the like due to its characteristics of non-toxicity, high transparency and biodegradability, and has been widely paid attention to in the industry. Currently, the preparation of PVA films mainly comprises two technical paths of a solution casting method and a melt processing method. The solution casting method has lower requirement on the thermal stability of the functional filler, but the solvent volatilizes in the forming process, so that the problems of high energy consumption and long period exist, the production efficiency is low, the production cost is higher, and the method is difficult to adapt to the large-scale industrial production requirement. In contrast, the melt processing method has the advantages of high efficiency and rapidness, is more suitable for large-scale industrial production, but is limited by the thermal performance defect of PVA material, namely, the melting temperature of PVA is about 230 ℃, the decomposition temperature interval is 200-250 ℃, the two are similar, the processing window is narrow, and simultaneously, higher requirements are also put forward on the thermal stability of functional fillers. In order to widen the processing window of PVA, the melting and decomposition temperature range of PVA is often widened by introducing a plasticizer in the industry, and the hot processing performance is improved. However, PVA itself belongs to inflammable materials, limiting Oxygen Index (LOI) is only about 19%, and the melting drop phenomenon is also caused during combustion, and although the introduction of plasticizer is helpful for processing, the melting drop problem in the combustion process can be further aggravated, and obvious fire safety hidden danger is brought, so that the improvement of the flame retardant property of PVA becomes a key premise of the industrialized application of PVA. Currently, the research on flame-retardant PVA composite materials is concentrated on the preparation of solution casting methods, and the research on preparing flame-retardant PVA composite materials by a melt processing method is relatively deficient. Flame retardants such as ammonium polyphosphate and phytic acid commonly used in the market can show excellent flame retardant effect in a solution casting system, but have poor applicability under the melt processing condition, namely the initial decomposition temperature of the phytic acid is generally lower than 160-210 ℃ required by PVA melt processing, the flame retardant effect cannot be exerted and PVA processing and molding can be possibly hindered due to insufficient thermal stability, and although the ammonium polyphosphate has higher thermal stability, acidic substances generated in the system can accelerate high-temperature dehydration and carbonization of PVA matrix in the PVA melt processing process, so that the material cannot be processed normally. In conclusion, the flame-retardant filler for melt processing the PVA composite material needs to simultaneously meet three core requirements of high thermal stability, no acid source and good compatibility with a PVA matrix, namely, the filler is easy to agglomerate due to insufficient compatibility, so that the mechanical property of the material is reduced. Therefore, a halogen-free flame retardant with high thermal stability, good compatibility and environmental protection is developed, and a melt processing strategy is adopted to prepare a flame-retardant polyvinyl alcohol film, so that the flame-retardant polyvinyl alcohol film has important practical significance for promoting the high-efficiency application of PVA materials in the environment of green sustainable development. Disclosure of Invention Aiming at the problems of poor suitability of a flame retardant, poor compatibility of a filler and a matrix and the like in the prior art, the invention provides a melt-processable green bio-based flame retardant polyvinyl alcohol composite material, which is characterized in that a high-thermal-stability green bio-based flame retardant CADCM is synthesized and compounded into a PVA base material through a high-efficiency melt processing technology, so that the PVA composite material with excellent flame retardant performance, good mechanical property and processing suitability is finally obtained. In order to solve the technical problems, the invention