The influence of flame retardant structure on UV stabilization approaches in polypropylene

UV stabilization of polypropylene fiber containing brominated flame retardants has been the focus of intense technical efforts with only limited success. Acid generated by the flame retardants deactivates HALS, thus severely reducing the HALS' effectiveness. Because of this interaction, flame retarded polypropylene fiber has been generally restricted to applications requiring little or no UV stability. Evaluation of structure-performance characteristics of both flame retardants and stabilizers allow development of packages which optimize processability, flame retardancy, and UV stability. This paper reviews progress in the stabilization of flame retarded PP fiber and presents new advances in this field.     

Effects of ageing on the fire behaviour of flame‐retarded polymers: a review

The influence of environmental ageing on the reaction to fire of flame‐retarded polymers is reviewed. Six types of stimuli have been identified as the most relevant parameters inducing fire behaviour modification: temperature, moisture, UV radiation, ionizing radiation, chemical solvent and physical stress. This review provides a state of the art and current comprehension of the effects of ageing on flame retardancy of polymers. Various physical and chemical phenomena lead to ageing and deterioration (or sometimes improvement) of the flame retardancy of polymers: release of additives (not only flame retardants) through thermal migration, solubilization, abrasion, etc., chemical degradation of the flame‐retardant system, and chemical or physical modification of the polymer structure (chain scission, crosslinking, diffusion of water, etc.). Obviously, ageing effects strongly depend on the material and the ageing scenario considered. Solutions to maintain flame‐retardant efficiency in aggressive conditions are also presented. © 2014 Society of Chemical Industry     

Thermal aging properties of flame retardant silicone rubber based on melamine cyanurate

In this work, an efficient preparation method for flame retardant silicon rubbers (FRSR) was established with using melamine cyanurate (MCA) as flame retardants. In order to analyze the thermal aging mechanisms and flame retardancy of FRSR, cone calorimetric test (CCT), Fourier transform infrared (FTIR) spectra, scanning electronic microscopy (SEM), and energy dispersive X-ray spectra were performed. Results indicated that the aging time significantly decreases the tensile strength and the elongation at break. SEM images revealed that the porous surface of the aged FRSR provide diffusion path for heat and oxygen, which resulted in a continuously increase in Shore A hardness due to the increase of cross-linking density during the aging process. FTIR spectra further proved that the MCA is well-embedded into samples and cross-linking reaction between free radicals of silicone rubber (SR) and oxygen was occurring during the aging process. Besides, CCT results showed that all FRSR samples before and after thermal aging exhibit excellent flame retardancy with compact and stable char residue layers, effectively hindering the heat transfer and oxygen diffusion. It was expected that our findings could provide important information to fabricate SR with flame retardancy and outstanding long-term thermal-aging resistance.     

影响聚丙烯阻燃性能的因素

本文主要对影响聚丙烯PP材料性能的因素进行了分析、研究,从阻燃剂选用的角度来说,阻燃剂的选用要从其热分解温度、熔点与聚丙烯的热分解温度、熔点相匹配;同时从不同PP的熔体流动速率角度、滑石粉对其影响程度等方面进行了分析。     

超声协助蒙脱土分散于聚磷酸铵阻燃聚丙烯的研究

阻燃剂能够增强聚丙烯（PP）的阻燃性能,但也会降低其力学性能,因此对阻燃剂进行改性以改善聚丙烯的力学性能显得至关重要。以传统的膨胀型阻燃剂（IFR）[由聚磷酸铵（APP）、季戊四醇（PER）、三聚氰胺（MA）组成]为PP阻燃。在合成APP过程中引入有机蒙脱土（OMt）。APP围绕OMt形成,剥离OMt使其能够较好地分散在阻燃剂中。为使OMt更好地分散在阻燃剂中,在磷酸氢二铵（DAP）、尿素（UREA）溶液中加入OMt,之后对溶液进行超声处理,蒸干后形成DAP-UREA-OMt与五氧化二磷反应生成APP。在PP中添加改性阻燃剂,有助于PP材料阻燃性能的提升与减缓力学性能的下降。当阻燃剂添加量为30%（阻燃剂添加量占总质量的质量分数）时,PP/IFR_APP/OMt复合材料的氧指数达到29.8%,通过V-0测试,拉伸强度为22.0 MPa,高出传统方法0.7 MPa。     

阻燃剂类型对聚碳酸酯阻燃性能的影响

分别选用溴化齐聚物、磺酸盐、聚硅氧烷混合物和磷酸酯阻燃剂对聚碳酸酯(PC)进行阻燃改性,研究了阻燃剂类型对PC阻燃性能的影响,同时探讨了试样厚度对阻燃性能测试结果的影响。结果表明,溴化齐聚物提升了PC的灼热丝起燃温度(GWIT),磺酸盐、聚硅氧烷混合物和磷酸酯降低了PC的GWIT;成炭对起燃的影响远小于热分解,决定GWIT高低的因素是热分解温度,热分解温度越高,GWIT越高。磺酸盐分解的SO2促使PC交联形成的产物为层碳或石墨化结构,不仅隔热、隔氧、阻止气体流通,还具有导电性,是真炭层,磺酸盐阻燃改性PC的相比电痕化指数由纯PC的175 V降低至150 V;聚硅氧烷混合物、磷酸酯及其分解物形成的“炭层”仅具有类似炭层的作用,无导电性,对PC的电痕化性能无影响。添加四种阻燃剂后PC的灼热丝可燃性指数、垂直燃烧等级均有不同程度的提升,针焰试验结果变好。随着试样厚度增加,溴化齐聚物阻燃PC的GWIT升高,磺酸盐和磷酸酯阻燃PC的GWIT降低,聚硅氧烷混合物阻燃PC的GWIT无明显变化。随着试样厚度增加,四种阻燃剂阻燃PC的其它阻燃性能整体变好,但磷酸酯阻燃PC的垂直燃烧等级仍为V–1级。     

大分子溴系复合阻燃剂对PS和发泡PS的阻燃改性

将大分子溴系阻燃剂(FR–122P)与溴化环氧树脂(2200HM)组成的复合阻燃剂应用于聚苯乙烯(PS)复合材料和发泡PS中,研究了复合阻燃剂的配比和含量对PS复合材料阻燃性能以及复合阻燃剂含量对发泡PS泡孔结构和阻燃性能的影响,采用热重分析、扫描电子显微镜观察、极限氧指数(LOI)测试、垂直燃烧(UL–94)和水平燃烧试验等手段进行了表征。结果表明,当FR–122P与2200HM质量比为4∶1、总添加量为25%时,PS复合材料的LOI可达25.8%,并可通过UL–94 V–0等级;当复合阻燃剂的添加量为40%时,可得到泡孔尺寸较小、泡孔密度较大、膨胀倍率较高的发泡PS复合材料,且其可通过泡沫水平燃烧的HF–2等级。大分子溴系阻燃剂与溴化环氧树脂的复合阻燃剂对PS和发泡PS复合材料具有较好的阻燃效果。     

新型含磷阻燃剂的制备及性能

以双三羟甲基丙烷为原料合成一种新型含磷阻燃剂,该阻燃剂分子量较大,具有稳定的环状结构,热稳定性高于常用阻燃剂,阻燃效果好。探讨了原料配比、反应温度、反应时间对产率的影响,考察了目标产物的热稳定性能及其对不同织物的阻燃效果,用傅里叶变换红外光谱仪表征了中间体及目标产物的结构。结果表明,当原料配比为1∶3时,磷化温度为50℃,磷化时间5h,胺化温度为75℃时,反应效果较好,收率可达90%以上。目标产物对于锦纶的阻燃效果比较明显,对涤纶、棉有一定的阻燃效果,对于混纺、腈纶阻燃效果不明显。     

PP/EPDM热塑性弹性体动态硫化阻燃材料制备及性能研究

研究了聚丙烯/三元乙丙橡胶(PP/EPDM)体系在过氧化二异丙苯(DCP)、硫磺(S)和酚醛树脂(PF)三种不同硫化条件下的动态硫化过程。探讨了膨胀型阻燃剂三聚氰胺磷酸盐(MP)和双季戊四醇(DPER)对PP/EPDM动态硫化体系力学性能和阻燃性能的影响。结果表明:在加入阻燃剂的情况下,PP/EPDM体系的阻燃性能得到了改善,但体系的力学性能下降较多。     

膨胀型阻燃剂在聚丙烯中的应用研究

使用磷酸、季戊四醇、三聚氰胺合成了一种膨胀型阻燃剂。采用热重分析（TGA）、红外光谱分析（FTIR）、氧指数晨6定和垂直燃烧实验，研究了所合成的膨胀型阻燃剂对聚丙烯的阻燃作用。与普通的膨胀型阻燃剂和包覆型膨胀阻燃剂的对比研究表明，该阻燃剂对聚．丙烯的阻燃性能优良，达到相同的阻燃效果（聚丙烯氧指数达到34％）时，用量较其它两种膨胀型阻燃剂明显减少。抗析出和防湖性能较其它两种膨胀型阻燃剂也有明显改善。     

溴系阻燃剂对阻燃HIPS耐候性能的影响

通过不同类型溴系阻燃剂与Sb2O3复配制备阻燃HIPS,考察不同类型溴系阻燃剂对阻燃HIPS耐紫外光老化性能影响,结果表明不同类型溴系阻燃对阻燃HIPS的影响有很大差异(300h氙灯老化的不同类型溴系阻燃HIPS色差值从3.5到56.8),通过分析不同溴系阻燃剂对阻燃HIPS耐候性能的影响,发现阻燃剂结构的稳定性是影响耐候性的主要因素,相同结构下随着溴含量增加,耐候性降低。     

膨胀型阻燃剂阻燃PP/SBS/POE共混物的性能研究

研究了聚磷酸胺类膨胀型阻燃剂（AP）和磷酸酯膨胀型阻燃剂(NP)的用量对聚丙烯（PP）/苯乙烯-丁二烯-苯乙烯共聚物（SBS）/乙烯-辛烯共聚物（POE）共混体系的力学性能、燃烧性能和遇水抗析出性能的影响。探讨了阻燃剂的析出机理,并从耐电压方面分析其在电线电缆领域应用的可行性。结果表明,NP具有更高的分解温度和残炭率。将AP与NP分别加入到PP/SBS/POE共混体系中,共混物的拉伸强度和断裂伸长率都降低,但阻燃性能提高。在相同添加量下,NP阻燃的共混物的拉伸强度和氧指数更高,而AP更能促进共混物成炭。AP和NP在热水浸泡过程中都会析出,析出过程是由表层向内部逐步析出的过程,析出量随着浸泡时间延长而增加。在相同的浸泡时间下,NP体系的析出量更小。浸泡后的共混物的力学性能和阻燃性能下降。     

匀泡剂对阻燃硬质聚氨酯泡沫塑料燃烧性能的影响

利用氧指数仪测定了全磷阻燃剂（DMMP、DEEP、V6）、卤代磷酸酯阻燃剂（TCEP、TCPP、TDCP）及两类阻燃剂复配对硬质聚氨酯泡沫塑料(RPUF)氧指数的影响。结果表明,全磷阻燃剂的阻燃效果优于卤代磷酸酯类阻燃剂;磷卤复配阻燃效果优于单一阻燃剂;单独使用DMMP或DMMP与TCEP复配使用阻燃效果最佳,这句话跟上一句不是矛盾吗？氧指数分别为23.0 %和24.5 %。利用锥形量热仪进一步研究了7种不同硅烷匀泡剂对RPUF阻燃性能的影响。结果表明,硅烷匀泡剂AK8803在提高RPUF的点燃时间以及降低RPUF燃烧释放热危害方面,优于其他6种匀泡剂;而硅烷匀泡剂L580则在降低RPUF燃烧烟气量方面优于其他6种匀泡剂。     

Effect of Phosphorus-Based Flame Retardants and PA6 on the Flame Retardancy and Thermal Degradation of Polypropylene

The investigation mainly focuses on the effect of polyamide 6 (PA6) and phosphorus based flame retardants (FRs) on improving the flame retardancy of polypropylene (PP). The flame retardant properties have been studied by limiting oxygen index, vertical burning test tests and cone calorimeter testing. The results demonstrate that PA6 and FRs can greatly improve the flame-retardant and thermal properties of PP. It’s found that the addition of PA6/APP/FRs can promote the formation of stable intumescent char layers. Those indicate that the flame retardancy of PA6/APP/FRs/PP composites is improved by the condensed-phase action of PA6/APP/FRs.     

An efficient approach to improving fire retardancy and smoke suppression for intumescent flame‐retardant polypropylene composites via incorporating organo‐modified sepiolite

In this work, an efficient approach to improving the fire retardancy and smoke suppression for intumescent flame‐retardant polypropylene (PP) composites is developed via incorporating functionalized sepiolite (organo‐modified sepiolite [ONSep]). The PP composites with different amounts of intumescent flame retardants and ONSep were prepared by melt compounding. The morphology, thermal behavior, fire retardancy, smoke suppression, and mechanical property of flame‐retardant PP composites were studied. The results indicate an appropriate amount of ONSep in the flame‐retardant PP composites can increase thermal degradation temperature and char formation as well as a reduction of the peak heat release rate and total heat release; moreover, the addition of ONSep significantly decreases the CO production, total smoke production, smoke production rate, and smoke temperature. Simultaneously, the impact strength of intumescent flame‐retardant PP composite is also maintained by introducing an appropriate amount of ONSep as compared with that without ONSep.     

Study of Fire Retardancy and Thermal and Mechanical Properties of HDPE-Wood Composites

This article reports a study of flame retardancy and thermal and mechanical properties of wood-plastic composites (WPCs) based on high-density polyethylene and pine flour. The study shows that sample composition plays an important role in WPCs' properties. The influence of additives like fillers (SiO₂ or CaCO₃) and flame retardants ammonium polyphosphate (APP) and pentaerythritol (PER) on WPCs' properties has been considered. The best properties are shown in samples using SiO₂ as filler and treated with the intumescent fire retardant APP/PER. Such samples have excellent fire retardancy with V-0 rating (UL-94 test) and imply that APP/PER fire retardant ensures effective fire retardancy for WPCs.     

环氧树脂改性水性聚氨酯阻燃涂料的研究

以E-44环氧树脂改性水性聚氨酯为基料,三聚氰胺、季戊四醇为阻燃剂,制备了一种阻燃涂料.测试了该涂料的附着力、耐水性、吸水率、阻燃性及热失重.结果表明,改性后涂料的涂膜附着力达到1级,耐水时间为240 h,吸水率16.5%,阻燃时间可达10 min以上,耐高温及阻燃性能明显提高.     

无卤阻燃聚丙烯材料的研究

用自制的膨胀型阻燃剂(IFR)与成炭剂、无机填料复配和聚丙烯(PP)共混,进行燃烧性能测试,考察了共混体系的燃烧行为;利用锥形量热仪研究了表面处理剂对膨胀阻燃体系的影响;用氧指数(OI)分析了阻燃剂及其他助剂在PP中的阻燃作用。结果表明,该阻燃体系既有较好的阻燃效果,又有抑烟作用。     

不同膨胀型阻燃剂改性聚丙烯/聚乳酸复合材料

用两种不同的膨胀型氮磷阻燃剂(IFR1和IFR2)阻燃改性聚丙烯(PP)/聚乳酸(PLA)复合材料。结果表明:两种阻燃剂在PP/PLA基体中都具有良好的分散性和界面粘合性。阻燃剂的加入降低了材料的力学性能,而含有25%阻燃剂的PP/PLA复合材料就能到达垂直燃烧试验(UL-94)的V0等级。燃烧过程中阻燃剂通过在材料表面形成致密的炭层来提高材料的阻燃性,其中IFR1对PP/PLA体系的阻燃改性效果更好。从力学性能和阻燃效果的双重考虑,质量含量25%的阻燃剂适合于PP/PLA材料的阻燃改性。     

疏水膨胀型阻燃聚丙烯的制备及与La2O3的协效阻燃

采用四乙氧基硅烷（TEOS）作为改性修饰剂,分别对季戊四醇（PER）和聚磷酸铵（APP）进行表面改性,制备得到膨胀型阻燃剂（IFR）,对改性后的IFR进行了红外光谱及热失重分析等表征,确认了硅的引入;向改性阻燃剂中加入纳米氧化镧（La2O3）作为阻燃协效剂,然后与聚丙烯（PP）混合,制备了疏水性膨胀型阻燃PP;研究了改性前后复合阻燃剂对PP阻燃性能和力学性能的影响。结果表明,改性后的阻燃体系表现出了较好的疏水性能,加入协效剂La2O3后,材料的阻燃性能和力学性能均较改性之前有所提高。