CN-119798866-B - Low-carbon natural fiber flame-retardant reinforced polypropylene composite material and preparation method thereof

Abstract

The invention discloses a low-carbon natural fiber flame-retardant reinforced polypropylene composite material and a preparation method thereof, wherein the low-carbon natural fiber flame-retardant reinforced polypropylene composite material is prepared from the following components, by weight, 65-70 parts of low-melt-index copolymerized polypropylene resin, 15-20 parts of natural coconut palm fiber master batch, 10-20 parts of composite flame-retardant components, 1-1.5 parts of toner, 1-3 parts of functional additives and 3-4 parts of compatilizers. The low-carbon natural fiber flame-retardant reinforced polypropylene composite material prepared by the invention has unique appearance, can be widely applied to the fields of automobile interior trim, interior decoration engineering and product outer packaging, can achieve V0 level flame retardance, greatly reduces the use risk of the product in a high-temperature environment, and can effectively reduce carbon emission in the production process due to the filled natural fiber part.

Inventors

• He Shuhang
• ZHANG JIE
• CAI YING
• CAI QING
• ZHOU ZHENLUN
• ZHOU WEN

Assignees

• 上海普利特复合材料股份有限公司
• 浙江普利特新材料有限公司
• 重庆普利特新材料有限公司
• 上海普利特化工新材料有限公司

Dates

Publication Date

20260512

Application Date

20241230

Claims (6)

1. 1. The low-carbon natural fiber flame-retardant reinforced polypropylene composite material is characterized by being prepared from the following components in parts by weight: 60-70 parts of low melt index copolymerized polypropylene resin, 10-15 parts of natural coconut palm fiber master batch, 15-20 parts of composite flame retardant unit, 1-1.5 parts of toner, 1-3 parts of functional auxiliary agent and 3-4 parts of compatilizer; The low-melt-index copolymerized polypropylene resin has an MFR of less than or equal to 5 g/10min under the test condition of 2.16kg and 230 ℃, the composite flame-retardant unit is a blend of expanded graphite, montmorillonite and piperazine pyrophosphate, wherein the expanded graphite is sulfuric acid intercalated expanded graphite, the ash content is less than or equal to 3%, the content is 25% -50%, the montmorillonite is quaternary ammonium salt organic modified montmorillonite, the content is 5% -10%, the content of piperazine pyrophosphate is 50% -70%, and the functional auxiliary agent is an antioxidant.
2. 2. The low-carbon natural fiber flame-retardant reinforced polypropylene composite material according to claim 1, wherein the effective content of the natural coconut coir master batch is more than or equal to 60%.
3. 3. The low-carbon natural fiber flame retardant reinforced polypropylene composite material according to claim 1, wherein the toner is furnace-type carbon black, and the specific surface area of the toner is 120-145m 2 /g.
4. 4. The low-carbon natural fiber flame retardant reinforced polypropylene composite material of claim 1, wherein the antioxidant is compounded by several of general 168, 616F, 3114,1076,1035 and DSTP, 1010.
5. 5. The low-carbon natural fiber flame-retardant reinforced polypropylene composite material of claim 1, wherein the compatilizer is at least one of maleic anhydride graft with a grafting rate of 0.5-2%, KH550 silane coupling agent, KH560 silane coupling agent and acrylic grafted PP.
6. 6. The method for preparing the low-carbon natural fiber flame retardant reinforced polypropylene composite material according to any one of claims 1 to 5, comprising the following steps: (1) Adding montmorillonite, expanded graphite and piperazine pyrophosphate powder into ethanol solution containing 5% of silane coupling agent according to a certain proportion, uniformly stirring, mixing for 1h, and drying to constant weight; (2) Mixing and stirring raw materials of polypropylene, a compatilizer, an antioxidant and toner in proportion at high speed; (3) Uniformly mixing the materials in the step (2), feeding the mixture into a main feeding port of a double-screw extruder, wherein the rotation speed of the main machine is 300-500rpm, adding coconut coir master batch and a composite flame retardant component into a side feeding port positioned at the middle section, and adding a vacuum pumping system in the stirring process, wherein the process comprises the steps of 150-170 ℃ in a first area, 160-180 ℃ in a second area, 160-180 ℃ in a third area, 170-190 ℃ in a fourth area, 20-60 ℃ in a cooling water tank, and 2-4mm in the grain cutting length of a grain cutting machine.

Description

Low-carbon natural fiber flame-retardant reinforced polypropylene composite material and preparation method thereof Technical Field The invention relates to the technical field of polypropylene materials, in particular to a low-carbon natural fiber flame-retardant reinforced polypropylene composite material and a preparation method thereof. The material is suitable for automobile interior trim, interior decoration engineering, product outer packaging materials and the like. Technical Field With the progress of technology and the development of society, people pay more and more attention to the environmental protection performance and sustainability of materials. Polypropylene is widely used as a light and high-strength plastic material in various fields such as automobiles, buildings, packaging and the like. In recent years more and more natural fibres have been used for filling polypropylene modification in order to achieve low carbonization of polypropylene materials. The coconut fiber is a natural fiber material extracted from coconut shells, has the characteristics of low carbon value, excellent mechanical property, high moisture resistance and the like, and is an excellent choice of filling materials. Meanwhile, the coconut thread filled polypropylene material has unique appearance characteristics and soft visual sense, and is widely applied to aspects of interior decoration, product outer packaging, automobile interior decoration and the like at present. However, the insufficient flame retardance of the traditional coconut fiber filled polypropylene material severely limits the application of the traditional coconut fiber filled polypropylene material in wider fields. The simple halogen-free flame-retardant system is easy to face two problems, firstly, the flame-retardant efficiency is low, the traditional halogen-free flame-retardant system needs to be added in an amount exceeding 25% to achieve VO flame retardance, and the overall cost is too high and the reduction of carbon emission is not facilitated. Secondly, the fibers in the fiber filling system are not well combined with the flame retardant components, and in the combustion process, the arrangement of the fibers can form a puncture effect on a continuous carbon layer required for flame retardance, so that the flame retardant effect is reduced. In order to solve the problems, the invention provides a low-carbon natural fiber flame-retardant reinforced polypropylene composite material and a preparation method thereof, and aims to provide a novel material which is environment-friendly and has excellent flame retardant property. According to the composite material, the composite flame retardant is introduced, and the flame retardant property of the material is improved through the synergistic effect of the Expanded Graphite (EG), montmorillonite (MMT) and piperazine pyrophosphate (PAPP) halogen-free flame retardant, so that compared with the traditional halogen-free flame retardant system, the novel flame retardant system has two systems of physical expansion flame retardance and chemical expansion flame retardance, and the addition amount of the flame retardant can be effectively reduced. Meanwhile, the coconut palm fiber master batch of the high melt index small molecular weight polypropylene substrate and the flame retardant component are selected to be blended and extruded, the organic modified MMT and the coupling agent in the composite flame retardant are easy to combine with the fiber to form a heat insulation layer, the heat insulation effect is achieved on the fiber, and the flame retardant property and the heat resistance of the material are effectively improved. Disclosure of Invention The invention aims to solve the technical problem that the existing natural coconut fiber reinforced polypropylene material has insufficient flame retardant property, and provides a low-carbon natural fiber flame retardant reinforced polypropylene composite material and a preparation method thereof. In order to solve the technical problems, the physical and chemical double expansion synergistic flame-retardant system is prepared by blending EG, MMT and PAPP. Meanwhile, the characteristic that small molecular weight molecules tend to float on the surface layer of the material in the microstructure is utilized, a mode that high molecular weight master batch is matched with extremely low molecular weight base materials is selected, and natural fibers and flame retardant components are effectively combined through coupling, so that the flame retardant grade and heat resistance of the material are improved. The obtained material has the advantage of low carbon filled with natural fibers, has flame retardant property, and can be used for expanding the application range of the material to a certain extent. The invention adopts the following technical scheme: The low-carbon natural fiber flame-retardant reinforced polypropylene composite material comprises the f