MCA/APP协同作用对E/VAC燃烧性能与成炭机制的影响

通过筛选复配,组成了以三聚氰胺氰尿酸盐(MCA)为气源、聚磷酸铵(APP)为酸源的化学膨胀复配阻燃体系,用于对(乙烯/乙酸乙烯酯)共聚物(E/VAC)进行阻燃改性。通过极限氧指数(LOI)测试、垂直燃烧实验研究了MCA/APP协同阻燃作用对E/VAC燃烧性能的影响;并运用光学显微镜(OL)、扫描电子显微镜(SEM)和傅立叶变换红外光谱(FTIR)等分析手段对阻燃E/VAC体系燃烧后的结构进行了分析。结果表明,随着APP在MCA/APP体系中比例的增加,阻燃E/VAC的LOI由25.2%提高到28.3%;当MCA/APP配比为1.8∶1时,阻燃E/VAC的燃烧等级可以达到FV-0级;燃烧试样膨胀层的OL分析表明,随着MCA在MCA/APP体系中比例的增加,其膨胀层横截面处的孔洞增多、孔径变大,证明燃烧时形成了良好的膨胀和隔热层;燃烧试样炭层的OL和SEM分析表明,随着APP在MCA/APP体系中比例的增加,燃烧试样形成了具有良好阻燃效果的多孔泡沫状炭层;FTIR分析表明,阻燃E/VAC试样燃烧时发生脱水炭化现象。     

无卤阻燃ABS/TPU复合材料阻燃性能的研究

采用了微胶囊红磷(MRP)、氢氧化镁(MH)、聚硅氧烷组成复合阻燃剂,对丙烯腈-丁二烯-苯乙烯(ABS)/热塑性聚氨酯(TPU)合金进行改性,获得了环保型阻燃ABS/TPU复合材料。对该复合材料进行了阻燃性能、热稳定性测试和炭层形貌分析。结果表明,当复合阻燃剂MRP/MH质量比为1/1且添加量为16份时,复合材料的极限氧指数(LOI)为25.7%,垂直燃烧性能通过FV-0级;TPU结构中因含氧,有利于MRP/MH阻燃体系阻燃;添加6份聚硅氧烷,复合材料垂直燃烧级别达到FV-0级,聚硅氧烷燃烧过程中通过改变炭层形貌,提高阻燃性。     

MCA协同阻燃EVA/MH体系性能研究

以乙烯-乙酸乙烯共聚物(EVA)为基体树脂,氢氧化镁(MH)为阻燃剂,以无毒、高润滑的三聚氰胺氰尿酸盐(MCA)为协同剂,制备了MCA协同EVA/MH复合阻燃体系,系统研究了其力学性能、燃烧性能、加工流动性能和尺寸稳定性。结果表明:MCA能够改善体系的力学性能,在提高韧性的同时,屈服强度和断裂强度也有所提高。同时,MCA能减缓体系燃烧剧烈程度,抑制燃烧滴落现象,但体系的氧指数有所降低。此外,MCA能够改善复合体系的加工性能,MFR增加,扭矩降低。MCA使EVA/MH复合材料的膨胀率由0.87%降低到0.17%,尺寸稳定性提高。     

LLDPE/EVA/改性MH/MRP阻燃体系的研究

选用乙烯-醋酸乙烯共聚物/改性氢氧化镁/微胶囊红磷(EVA/改性MH/MRP)为复合阻燃体系,研究体系的力学性能及阻燃性能,并通过扫描电镜观察材料燃烧后炭层的表面形貌。结果表明:当LLDPE/EVA/改性MH/MRP添加比例为60:40:70:10时,拉伸强度为11.3 MPa,断裂伸长率为353%,氧指数为31.4%,垂直燃烧试验通过UL 94V-0级,体系具有良好的阻燃协效作用和力学相容性。     

MCA协效阻燃EVA/MH和EVA/ATH及其作用机理研究

利用垂直燃烧(UL-94)、极限氧指数、热失重分析(TGA)、扫描电镜(SEM)等测试方法从热分解阶段的机理、燃烧表面炭层形貌等方面对三聚氰胺氰尿酸盐(MCA)在乙烯-乙酸乙烯共聚物(EVA)/氢氧化镁(MH)和EVA/氢氧化铝(ATH)体系的协效阻燃机理进行研究。结果表明,在阻燃剂总含量相同的情况下,EVA/MH/MCA体系的UL-94达到V-0级,极限氧指数可达到33.4%,而EVA/ATH/MCA则无法通过UL-94测试;EVA/MH/MCA体系热稳定性更好;EVA/MH/MCA体系形成的炭层结构更加紧密,阻燃性能更好。     

多壁碳纳米管协效复合膨胀阻燃剂阻燃EVA的研究

以乙烯-乙酸乙烯酯共聚物(EVA)为基体树脂,大分子磷氮复合阻燃剂(NPS)为主阻燃剂,以多壁碳纳米管(MWCNTs)为协效剂,制备了低烟无卤阻燃EVA复合材料。采用极限氧指数(LOI)、热重分析(TGA)、扫描电镜(SEM)、力学性能和动态热力学性能(DMA)测试等手段对复合材料进行测定,重点考察了MWCNTs对膨胀阻燃EVA体系的影响,探讨了其作用机理。结果表明:MWCNTs对阻燃EVA体系具有很好的协同效应;MWCNTs的加入提高了膨胀炭层在高温时的热稳定性,增加了高温时的残炭量;MWCNTs可以改善膨胀炭层的形貌,提高炭层的隔热性能;0.5%的MWCNTs与29.5%的NPS复配,试样的LOI达到33.6%,拉伸强度达到12.37 MPa;MWCNTs用量在3%以内时,体系仍能保持较好的电绝缘性。     

有机硅/碳酸钾协效剂对PA-6/MCA体系阻燃性能和熔融滴落行为的影响

以PA-6为基体,MCA阻燃剂,以有机硅胶(SG)/碳酸钾(K2CO3)两者的复配物(SG/K2CO3)为协效剂,重点研究了协效剂的配比和用量对PA-6/MCA复合材料阻燃性能和熔融滴落行为的影响,同时采用熔融指数对PA-6/MCA复合体系抗熔融滴落作用进行了研究分析。结果表明,阻燃协效剂SG/K2CO3添加量为8份,配比为65∶35时,PA-6/MCA复合体系的氧指数最大,垂直燃烧测试达到FV-0级;同时,配比为50∶50时燃烧样条表面结炭明显,炭层较完整,熔融滴落现象消失;熔融指数研究表明,SG/K2CO3协效剂的加入,PA-6/MCA复合体系的熔融指数明显降低,SG/K2CO3具有增粘作用,可以有效防止熔滴滴落的作用。     

有机蒙脱土对EVA/IFR复合材料阻燃性能的影响

以聚磷酸铵（APP）和季戊四醇（PER）为膨胀型阻燃剂（IFR）制备了含有蒙脱土的无卤阻燃乙烯 醋酸乙烯共聚物（EVA）复合材料。通过极限氧指数、热失重分析、锥形量热分析等手段研究了有机蒙脱土(OMMT)的存在对EVA阻燃性能和热降解性能的影响,并通过扫描电子显微镜对复合材料残炭表面形貌进行了观察和分析。结果表明,加入有机蒙脱土可以促进复合材料成炭、改善炭层质量,从而起到了良好的隔热、抑烟作用;OMMT的最佳添加量为3份（质量份数,下同）,复合材料的极限氧指数可达到29.4 %,垂直燃烧可达V 0级。     

氢氧化镁对膨胀阻燃乙烯-醋酸乙烯酯共聚物性能的影响

考察了低添加量的氢氧化镁(MH)对乙烯-醋酸乙烯(EVA)、聚磷酸铵(APP)、双季戊四醇(DPER)复配组成膨胀型阻燃材料的力学性能、燃烧性能、加工性能的影响,通过以上研究,拓宽以APP为主的膨胀型阻燃剂用协效剂的选择范围,提高材料的阻燃效率、降低成本和添加量。结果表明:MH添加量为3份时,能够与膨胀阻燃体系形成良好协效作用,使氧指数提高,当添加量继续增加,产生了相反的作用,造成氧指数的急剧下降,而随着MH添加量的增加,阻燃材料的拉伸性能基本保持不变,硬度上升,熔体流动速率有小幅下降。     

MCA协效膨胀阻燃LDPE泡沫材料的研究

以木质素为炭源、聚磷酸铵(APP)为酸源和气源、三聚氰胺尿酸盐(MCA)为协效阻燃剂、低密度聚乙烯(LDPE)为基体材料,采用共混塑炼-热压法制备膨胀阻燃LDPE泡沫材料,研究MCA对膨胀阻燃LDPE泡沫材料结构与性能的影响。结果表明:MCA加入使膨胀阻燃LDPE泡沫材料的刚性和模量有所提高,同时提高了膨胀阻燃发泡体系的阻燃效率。当APP与MCA的质量比为6∶5时,极限氧指提高到28.1%,垂直燃烧达到FV-0级,无滴落现象,700℃残炭量提高到32.3%,燃烧后炭层结构光滑致密。     

Combustion Behavior and Thermal Oxidative Degradation of EVA Containing Intumescent Flame Retardant

Microencapsulated ammonium polyphosphate (VAPP) with poly(vinyl alcohol)- melamine-formaldehyde (VMF) shell was introduced in ethylene vinyl acetate copolymer (EVA) to improve its flame retardancy. Due to the presence of VMF shell, VAPP shows better compatibility, flame retardancy and water resistance compared with ammonium polyphosphate (APP) in EVA. The flammability of EVA and its flame-retarded composites was studied by LOI, UL-94 and cone calorimeter. The composite containing 40 wt% VAPP can pass V-0 in UL-94 test, and hot water treatment shows few effects on its LOI value and UL-94 rating. The cone results indicated that the use of VAPP in EVA can significantly decrease heat release rate and total heat release compared with APP. To understand the mechanism of action of VAPP, dynamic FTIR experiments were carried out on EVA and EVA/VAPP composites. Based on above studies, the flame retardant mechanism of VAPP in EVA composite is discussed.     

磷氮复配无卤阻燃聚苯醚合金的研究

采用固体阻燃剂间苯二酚双[二(2,6-二甲苯基)磷酸酯](RXP)及其与三聚氰胺氰脲酸盐(MCA)的复配阻燃剂,制备了无卤阻燃聚苯醚/高抗冲聚苯乙烯/苯乙烯-丁二烯-苯乙烯热塑性弹性体(PPE/PS-HI/SBS)合金,通过氧指数、水平垂直燃烧、扫描电子显微镜、力学性能等测试分析方法,考察了PPE/PS-HL/SBS合...     

碱式碳酸镁基复合阻燃剂的制备及其阻燃性能研究

采用硅烷表面处理的碱式碳酸镁纳米片和氢氧化镁以及氢氧化铝为复合阻燃剂,通过密炼模压法制备了一系列复配阻燃剂协效阻燃EVA的复合材料。利用拉伸性能测试仪、熔融指数仪、垂直燃烧测试仪和锥形量热仪分别测试了复合材料的力学性能、加工流动性能和阻燃性能,利用热重分析仪测试了复配阻燃剂的热分解行为。结果表明,复配阻燃剂以适当比例协效阻燃EVA在更宽的燃烧温度范围内发生分解,能够起到更好的阻燃效果。并且复配阻燃剂/EVA复合材料的热释放速率和烟释放率大幅度降低,分别为181.06 kW/m²和0.032 m²/s。另外,复配阻燃剂/EVA复合材料的拉伸强度达到9.73 MPa,断裂伸长率为155.07%,每10 min熔融指数为1.00 g,符合电线电缆行业标准。     

Flammability of EVA/IFR (APP/PER/ZB system) and EVA/IFR/synergist (CaCO3, NG,and EG) composites

Poly(ethylene‐co‐vinyl acetate)/intumescent flame retardant (ammonium polyphosphate/pentaerythritol/zinc borate system) composites‐EVA/IFR (APP/PER/ZB system) and EVA/IFR/Synergist [CaCO₃, natural graphite, or expanded graphite (EG)] composites have been prepared by melting compounding method. The flammability, the combustion process, the quantity of the residual chars, the morphology of the residual chars, and the thermal stability of the chars have been investigated by cone calorimeter, scanning electron microscopy and thermo gravimetric analysis. The results indicate that heat release rate (HRR), total heat released, and total smoke release (TSR) of EVA/IFR (IFR 30 phr) composite decrease to about 67.1, 78.2, and 64% of that of pure EVA, respectively. HRR, THR, and TSR of EVA/IFR/EG (IFR 9 phr, EG 1phr) composite decrease to about 62.1, 76.2, and 44% of that of pure EVA, respectively. The quantity, the thermal stability of residual chars and the char structure are discussed to find the reasons of the phenomenon above. It has been found that the flame retardant of EVA vulcanizates is improved and the fire jeopardizing is dramatically reduced due to the addition of IFR and synergist, which can give some advice to design formulations for practical applications as cable. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

无卤阻燃聚烯烃电缆护套料的研制

以乙烯-乙酸乙烯酯塑料(EVAC)为基体,氢氧化镁[Mg(OH)2]为阻燃剂,红磷(RP)和氰尿酸三聚氰胺(MCA)为阻燃协效剂,制备了一种可应用于电缆护套料的无卤阻燃复合材料.探讨了Mg(OH)2、RP、MCA用量对复合材料性能的影响.结果表明,当Mg(OH)2为120份、RP为3.0份、MCA为3.O份、交联剂过氧...     

A novel intumescent flame retardant-functionalized montmorillonite: Preparation,characterization, and flammability properties

2,4,8,10-Tetraoxa-3,9-diphosphaspiro[5.5]-undecane-3,9-dioxide-disubstitutio-acetamide-N,N-dimethyl-N-hexadecy-ammonium bromide (PDHAB) containing phosphorus–nitrogen structure was synthesized and characterized. A novel flame retardant, montmorillonite (Mt) modified by PDHAB (PDHAB-Mt), was prepared by ion-exchange of sodium montmorillonite (Na⁺-Mt) with PDHAB. The results of X-ray diffraction (XRD) indicated that PDHAB had intercalated with Na⁺-Mt and exfoliated LDPE/EVA/20% PDHAB-Mt nanocomposites had been obtained by polymer melt intercalation which was further supported by TEM. The flammability of LDPE/EVA/PDHAB-Mt nanocomposites was investigated by the cone calorimeter test. The results showed that the addition of flame retardant PDHAB-Mt enhanced the flame retardancy of LDPE/EVA blend significantly. The results of SEM and TEM indicated that PDHAB-Mt can achieve better dispersion in the chars after combustion and the intumescent char is formed for LDPE/EVA/PDHAB-Mt nanocomposites after combustion. It is found that the char structure plays an important role for PDHAB-Mt in LDPE/EVA blend. The flame retardancy of LDPE/EVA blend was also significantly improved by an addition of PDHAB-Mt in LDPE/EVA blend.     

无卤膨胀复合阻燃低密度聚乙烯/乙烯-醋酸乙烯酯共混物的研究

分别采用三聚氰胺氰尿酸盐(MCA)、微胶囊红磷(MCP)以及氢氧化镁[Mg(OH)2]等与膨胀型阻燃剂PNP进行复配,研究了不同阻燃剂及其配比对低密度聚乙烯/乙烯-醋酸乙烯酯(PE-LD/EVA)共混物的阻燃和力学性能的影响。结果表明,在PE-LD/EVA为70/30的基体树脂中,当复合阻燃剂的含量为35%时,PNP/MCA的最佳配比为3/2,阻燃材料的极限氧指数为30.8%;PNP/MCA/MCP的最佳比例为24/16/4,阻燃材料极限氧指数为32.3%;PNP/MCA/MCP/Mg(OH)2的最佳比例为24/16/4/22,阻燃材料的极限氧指数为30.9%,垂直燃烧达到UL 94V-0级,拉伸强度为11.1MPa,断裂伸长率为80.6%。     

硅酸盐纳米短纤维增强EVA复合材料的阻燃和力学性能

以氢氧化镁[Mg(OH)2]和微胶囊红磷（MRP）为阻燃剂制备了无卤阻燃乙烯-醋酸乙烯共聚物（EVA）复合材料。通过极限氧指数、热失重分析和力学性能研究了硅酸盐纳米短纤维 (SNF) 以及马来酸酐接枝乙烯-醋酸乙烯共聚物（EVA-g-MAH）的加入对EVA阻燃性能和力学性能的影响,并通过扫描电子显微镜对其断面形貌和残炭表面形貌进行了观察和分析。结果表明,加入适量的EVA-g-MAH可以提高复合材料的极限氧指数和力学性能,加入12份的EVA-g-MAH后,材料的拉伸强度可达到10.2 MPa,断裂伸长率达到521 %,极限氧指数为39%,垂直燃烧达到V-0级别;加入适量的SNF后,可以显著提高复合材料的拉伸强度,当添加20份的SNF后,复合材料各性能最优,拉伸强度为12.3 MPa,断裂伸长率为210 %,极限氧指数为38%,垂直燃烧达到V-0级别。     

Ethylene vinyl acetate/layered silicate nanocomposites prepared by a surfactant-free method: Enhanced flame retardant and mechanical properties

Exfoliated EVA/layered silicate nanocomposites were prepared by a masterbatch process using polymer-modified layered silicate instead of small molecule surfactant-modified clays. The nanocomposites exhibited improved mechanical properties and flame retardancy. Microscale flammability test showed that the heat release capacity (HRC) and total heat release (THR) were reduced by 21-24% and 16%, respectively. Radiant gasification studies revealed that the exfoliated EVA nanocomposites exhibited better improvements in flame retardant properties of EVA than did the corresponding intercalated nanocomposites. The peak mass loss rate of the exfoliated EVA nanocomposite containing about 5 wt% clay was reduced by 80% and the mass loss rate plot was spread over a much longer period of time. The mechanical and flammability tests revealed that the observed improvements in all the desirable properties were due to the presence of both the incorporated polymeric surfactant and the nanoclay.