MG–PF包覆EPS泡沫阻燃及力学性能研究

采用强酸氧化法对石墨进行改性,得到与酚醛树脂(PF)有良好相容性的改性石墨(MG),然后在MG上合成PF,制得可发性聚苯乙烯(EPS)用包覆阻燃剂(MG–PF),将MG–PF涂覆到已预发泡的EPS珠粒上,经二次发泡成型制得MG–PF包覆阻燃EPS材料。研究了石墨的改性效果,以及MG–PF用量与MG–PF中MG含量对材料阻燃性能和力学性能的影响。结果表明,石墨经过改性后,所制得的MG–PF具有较好的稳定性,从而进一步提高了阻燃材料的性能;MG–PF中MG的含量越高,材料的极限氧指数(LOI)随MG–PF用量增加而提高的幅度越大,水平和垂直燃烧等级达到HF-1和V–0级时所需的MG–PF用量越低,但力学性能随MG–PF用量增加而下降的幅度越大。当MG–PF中MG质量分数为30%,EPS与MG–PF质量比为1∶4时,材料的压缩强度为219 kPa,拉伸强度为299 kPa,满足工程应用要求,且LOI达到25.8%、水平和垂直燃烧等级分别为HF-1和V–0级,具有较好的综合性能。     

EG阻燃热固性聚苯乙烯泡沫保温板的性能

以可发性聚苯乙烯(EPS)为基材,利用酚醛树脂(PF)作为包覆剂,可膨胀石墨(EG)作为阻燃剂,利用包覆法,制备了一种无卤环保、阻燃性能好、力学性能优良的热固性PS外墙泡沫保温板。研究了PF与EG对EPS保温板阻燃及力学性能的影响,探究了阻燃机理。结果表明,使用PF作为包覆剂制得的EPS/PF泡沫保温板力学性能尤其是压缩强度明显提高,当PF用量为90份时,LOI值可由18%提升至27.9%;阻燃剂EG的加入,使得保温板的阻燃性能及压缩性能进一步提高,当添加4份的EG时,保温板的压缩强度最高,LOI值达到了29.4%,垂直燃烧等级达到V–0级,残炭率由纯EPS的10%提高到50%。     

超疏水三嗪系膨胀阻燃剂的制备及其应用

采用硅树脂对三嗪系膨胀阻燃剂(IFR)进行表面包覆改性,并通过静态接触角测试对其进行了润湿性能表征。然后将改性前后的IFR分别添加到聚丙烯(PP)中制备了阻燃PP材料,并测试研究了该材料的阻燃性能、力学性能及耐水性。结果表明:当硅树脂的包覆量为5%时,改性IFR的接触角由改性前的0°上升到了151.3°,表现出超疏水性能。与未改性IFR阻燃的PP材料相比,由改性IFR得到的阻燃PP材料,其阻燃性能略有降低,但阻燃剂与聚合物的相容性以及阻燃PP的力学性能有所改善;同时阻燃PP的耐水性能显著提高,其阻燃剂的水抽出率大大降低。当阻燃剂添加量为20%时,未改性IFR阻燃的PP材料,其阻燃剂抽出率为3.71%,且耐水性测试后材料的阻燃性能明显下降;而改性IFR阻燃的PP材料,其阻燃剂抽出率仅为0.38%,且耐水性测试后材料的阻燃性能基本保持不变,表现出优良的耐水性能。     

膨胀型阻燃剂包覆EPS泡沫的阻燃抑烟性能

采用树脂包覆法,用蜜胺树脂和聚磷酸铵/季戊四醇/三聚氰胺组成的膨胀型阻燃剂制备无卤阻燃发泡聚苯乙烯(EPS)泡沫,研究膨胀阻燃剂对EPS泡沫的阻燃性能、抑烟性能及力学性能的影响。结果表明,膨胀阻燃剂可以有效提高EPS泡沫的阻燃性能和抑烟性能,极限氧指数最高可提高到30.6%,UL-94达到V-0等级,生烟量下降35%,EPS泡沫的冲击强度也得到提高。     

石墨特性对EG/EPS复合阻燃材料性能的影响

聚苯乙烯泡沫塑料(E PS)应用广泛,但是有易燃的缺点,而可膨胀石墨(EG)具有阻燃性能.目前,学者主要研究了EG与其它阻燃剂的配比和种类对复合EPS阻燃材料的影响,很少系统探究石墨的特性如石墨的粒级、EG的添加量、膨胀体积对复合EPS阻燃材料的性能的影响.通过EG包覆改性EPS制备EG/EPS复合阻燃材料,确定EG的添加量、膨胀体积、原料粒级对EG/EPS复合材料的性能的影响,为阻燃剂EG的应用提供依据.试验确定的最佳条件为:EG添加量为10wt％;膨胀体积为120 mL·g-1;EG原料粒级-0.100 mm +0.074 mm.由SEM表征、热重分析可知,高温燃烧时,EG吸热分解吸收大量热源,降低EPS与热源的接触;同时EG在材料表面形成六边形骨架,起到隔绝热源的作用.     

微胶囊化聚磷酸铵阻燃单组分聚氨酯防水涂料的制备及性能研究

选用三聚氰胺和甲醛反应生成的三聚氰胺树脂作为包覆材料对聚磷酸铵进行包覆,制备了微胶囊化聚磷酸铵。用聚氧化丙烯二元醇(Acclaim2200)和聚氧化丙烯三元醇(4701)与甲苯二异氰酸酯(TDI)反应,并添加增塑剂、填料、阻燃剂等制备了阻燃单组分聚氨酯防水涂料。研究了聚醚比例、预聚体中—NCO含量、阻燃剂添加量等对涂料性能的影响。实验结果表明:m(2200)∶m(4701)=2∶1,—NCO含量为3.5%(质量分数),微胶囊包覆聚磷酸铵(APP)添加量为32%时,阻燃单组分聚氨酯防水涂料综合性能优良。     

膨胀型阻燃剂的疏水改性及对水性阻燃涂料性能的影响

为了提高水性阻燃涂层的耐水性,以环氧树脂(EP)作为包覆材料,分别采用单一组分和混合组分改性两种工艺对阻燃剂〔聚磷酸铵(APP)、三聚氰胺(MEL)和季戊四醇(PER)〕进行包覆改性,制备出了改性阻燃剂及水性阻燃涂层。借助FTIR分析阻燃剂表面基团;采用SEM观察其微观结构;测量阻燃剂的接触角,并对其粒度分布进行统计;借助TG对阻燃剂及水性阻燃涂层进行测试;并参考国标GB/T1733—1993对涂层耐水性进行了测试。结果表明:两种工艺制备的阻燃剂其表面均包覆EP,且EP用量为阻燃剂质量的15%时,疏水效果达到最佳;阻燃剂经改性后其溶解度降低,接触角增大,使水性阻燃涂层耐水性显著提高,且阻燃剂采用混合组分改性效率更高;聚磷酸铵与EP发生交联生成不饱和富碳结构,加固残炭碳骨架的稳定性及增加涂层残余物的质量。     

不饱和聚酯树脂改性与阻燃、增韧性能研究

为了改善不饱和聚酯树脂(UPR)易燃烧、增韧性能差等缺点,以蜜胺包覆聚磷酸铵微胶囊为阻燃剂,以纳米二氧化硅为增强剂,分别对其进行阻燃和增强改性。研究了微胶囊阻燃剂和纳米二氧化硅对UPR的阻燃性能的影响,研究结果表明:蜜胺包覆聚磷酸铵微胶囊对UPR具有良好的阻燃效果,当微胶囊阻燃剂添加量为25%时,阻燃效果最优,此时材料无损坏长度和无熔滴,但弯曲强度降到了38.80MPa。当采用5%纳米二氧化硅和25%微胶囊协同改性UPR时,阻燃和弯曲性能均有显著的改善,此时弯曲强度达到70.78MPa,阻燃效果最优,无损坏长度和无熔滴。     

新型膨胀型阻燃剂阻燃聚丙烯的研究

通过微胶囊化技术合成了新型磷氮体系无卤膨胀型阻燃剂ANTI-6,用ANTI-6对聚丙烯(PP)进行阻燃改性。研究了阻燃剂ANTI-6中聚磷酸铵的微胶囊包覆;考察了阻燃剂对PP的阻燃性能、力学性能和耐水性等的影响。结果表明:包覆的聚磷酸铵粒度均匀致密,热稳定性提高;PP中添加25%ANTI-6阻燃剂可以获得良好的阻燃效果,氧指数达到30,阻燃性达UL94V-0级,改性PP具有优越的综合性能,耐热水性优于国外同类产品。     

包覆型MCA/PA6复合材料的制备及其阻燃性研究

以水为反应介质、无水乙醇为溶剂,将正硅酸四乙酯(TEOS)制备成二氧化硅(SiO_2)溶胶,利用溶胶的网络结构对三聚氰胺氰尿酸盐(MCA)进行表面包覆,制备出包覆型MCA阻燃剂;通过熔融共混方式,将包覆前后MCA与聚己内酰胺(PA 6)切片混合制备成不同阻燃剂含量的阻燃PA 6复合材料;采用红外光谱仪X射线光电子能谱仪、差示扫描量热仪、热重分析仪、垂直燃烧法和极限氧指数法等研究了阻燃PA 6复合材料的结构、热性能及阻燃性能。结果表明:SiO_2溶胶成功接枝在MCA表面,且主要分子结构没有发生改变;随着阻燃剂含量的增加,PA 6复合材料的熔点均有降低,但下降幅度较小;包覆型MCA在材料燃烧过程中能够有效参与成炭,在材料表面形成致密的保护层,增强PA 6复合材料的凝聚相阻燃效果,提高其阻燃性能;随着阻燃剂含量增加,PA 6复合材料的阻燃性逐步提高,添加包覆型MCA质量分数为8%时,PA 6复合材料阻燃性可达到UL-94 V-0等级,极限氧指数为28%。     

Soybean meal-based adhesive enhanced by MUF resin

Soybean meal flour, polyethylene glycol (PEG), sodium hydroxide (NaOH), and a melamine-urea-formaldehyde (MUF) resin were used to formulate soybean meal/MUF resin adhesive. Effects of the adhesive components on the water resistance and formaldehyde emission were measured on three-ply plywood. The viscosity and solid content of the different adhesive formulations were measured. The functional groups of the cured adhesives were evaluated. The results showed that the wet shear strength of plywood bonded by soybean meal/NaOH adhesive increased by 33% to 0.61 MPa after adding NaOH into the adhesive formulation. Addition of PEG reduced the viscosity of the soybean meal/NaOH/PEG adhesive by 91% to 34,489 cP. By using the MUF resin, the solid content of the soybean meal/MUF resin adhesive was improved to 39.2%, the viscosity of the adhesive was further reduced by 37% to 21,727 cP, and the wet shear strength of plywood bonded by the adhesive was increased to 0.95 MPa, which met the interior plywood requirements (≥0.7 MPa). The formaldehyde emission of plywood bonded by the soybean meal/MUF resin adhesive was obtained at 0.28 mg/L, which met the strictest requirement of the China National Standard (≤0.5 mg/L). FTIR showed using the MUF resin formed more  CH₂ group in the cured adhesive. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Improving Hot-Water Resistance of Melamine-Urea-Formaldehyde by Addition of PolyFox PF-151N Polymer

Melamine urea formaldehyde (MUF) thermosetting wood adhesives have poor performance at elevated temperatures and humid conditions. PolyFox PF-151N polymer was mixed at different loadings (0.05, 0.1, 0.5, and 1%) with MUF to improve properties, especially water resistance and bond strength. The physical properties of the optimized MUF/PolyFox PF-151N resins were measured. In order to evaluate the quality of optimized MUF/PolyFox PF-151N resins, particleboards were produced and physical and mechanical properties were investigated.

The results show that it is possible to add PolyFox PF-151N up to 0.1% to the MUF resin without altering the mechanical properties of the commercial MUF. The mechanical properties of the particleboard panels bonded with the optimal MUF/PolyFox PF-151N (99.9/0.1 by weight) resin were considerably increased as compared to the panels glued with neat MUF resin. The use of PolyFox significantly reduced 2-h and 24-h thickness swelling compared to the control panels.     

改性三聚氰胺-尿素-甲醛共缩聚树脂胶粘剂的合成

通过三聚氰胺-尿素-甲醛(MUF)共缩聚树脂胶粘剂的合成,探讨了三聚氰胺的用量对该MUF树脂耐水性能的影响及其规律。实验结果表明,当w(三聚氰胺)=43%～65%时,该MUF树脂的湿强度从0.93 MPa增加到2.74 MPa,耐沸水性明显提高;但是,当w(三聚氰胺)>65%时,该MUF树脂的湿强度增长极其缓慢,其耐沸水性提高并不明显;通过引入复合改性剂和适量的水,可使该MUF树脂的游离甲醛含量降低50%、成本降低10%～15%、固含量基本不变、胶合强度和耐沸水性均有所提高且适用期良好。     

三聚氰胺含量对MUF性能的影响

MUF(三聚氰胺-尿素-甲醛共缩聚树脂)兼具UF(脲醛树脂)和MF(三聚氰胺甲醛树脂)的优点,通过调节m(三聚氰胺)/m(尿素)配比,可得到性价比较高的MUF;然后采用MUF胶粘剂制备刨花板,并考察了三聚氰胺含量对刨花板的内结合强度、耐水性和耐沸水性等影响。结果表明:三聚氰胺的引入,虽能有效提高MUF的性能,但并非加量越多越好;当w(三聚氰胺)=11.0%~14.0%时,MUF的性价比相对最高,相应刨花板的内结合强度、耐水性和耐沸水性俱佳。     

A Soy Flour-Based Adhesive Reinforced by Low Addition of MUF Resin

The desire to prepare a lower-cost soy-based adhesive has led to an interest in using the abundant and inexpensive soy flour (SF) as a substitute for expensive soy protein isolates (SPI) in wood adhesives. However, the weakness of this adhesive is poor water-resistance and bonding strength due to a low protein content, which limits its application in the wood industry. The objective of this research was to provide a simple and useful approach for improving the adhesion performance of SF-based adhesive by introducing a small addition of melamine-urea-formaldehyde (MUF) resin into the cured system. The optimum addition level of MUF resin, as well as the adhesion performance and conformation change of SF-based adhesive, were investigated. The analytical results indicated that the co-condensed methylene bridges were formed through the reaction of methylol groups of MUF resin with soy units during the hot-press process. The addition of MUF resin, not only significantly decrease the viscosity of SF-based adhesive but also increase its water-resistance and wet shear strength value. The SF-based adhesive containing 20% MUF resin, is a relatively low-cost adhesive, has a reasonable viscosity, and moreover can pass the Chinese Industrial Standard requirement (0.7 MPa) for interior plywood panels.     

Effects of diatomite inorganic fillers on the properties of a melamine–urea–formaldehyde resin

In this study, a low‐cost diatomite was used to partly substitute wheat flour as one type of melamine–urea–formaldehyde (MUF) resin filler. Five‐ply plywood was fabricated, and its performance was measured. The crystallinity, fracture surface, and functional groups were tested to determine the effects of diatomite on the performance of the MUF resin. The results show that diatomite was well distributed in the MUF resin system and formed an embedding structure; this improved the wet shear strength of the resulting plywood by 33% to 1.36 MPa. Diatomite captured the free formaldehyde in the resin and the microporous structure formed in the resin accelerate formaldehyde release of the plywood. Consequently, the formaldehyde emission of the plywood was reduced. The diatomite partly replaced wheat flour as an MUF resin filler and could be applied in the plywood industry. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44095.     

三聚氰胺-尿素-甲醛共缩聚树脂胶粘剂的研制

通过合成三聚氰胺-尿素-甲醛树脂(MUF)胶粘剂,探讨了三聚氰胺用量对该MUF胶粘剂耐水性和其它性能的影响。结果表明:随着三聚氰胺用量的增加,MUF胶粘剂的耐水性能提高、固含量增大、固化时间和储存期延长,并且胶合板剪切强度增大,但MUF胶粘剂中游离醛含量降低;当w(三聚氰胺)40%时,MUF胶粘剂性能提高并不明显,为了降低成本,选择w(三聚氰胺)=30%～40%时较适宜;三聚氰胺用量不同是影响MUF结构和基团含量的主要因素。     

三聚氰胺-尿素-甲醛共缩聚树脂的性能研究

合成了三聚氰胺-尿素-甲醛(MUF)共缩聚树脂,考察了不同施胶量、固化剂用量及木材种类对胶合木性能的影响。结果表明,MUF共缩聚树脂用量为300g/m2,双面施胶,固化剂用量在1~2%时,生产的胶合木性能最优。     

Variation of MUF and PMUF resins mass fractions during preparation

The variation of molecular mass distribution with the progress of the reaction was studied for the following: (i) sequential‐type melamine–urea–formaldehyde (MUF) resin formulations in which the sequence of addition of chemicals follows well‐defined species reactivity principles; (ii) a nonsequential MUF formulation in which simultaneous melamine and urea competition for formaldehyde yields a MF resin cocondensed with small amounts of urea. This resin became soaked with reacted and unreacted monomeric urea species. (iii) A PMUF resin, namely a MUF resin with a small proportion of phenol (7.8% by weight on melamine and urea) cocondensed with the main MUF fraction. All the formulations used were industrial resins formulations in current use. Development and variation of molecular mass fractions, from which performance and other useful resin parameters depend, have been found to depend on the type of resin formulation used for these type of aminoplastic resins. The two very different MUF resin formulations yielded different variations in molecular mass fractions during the progress of the reaction and during the so‐called ambient temperature “maturing” of the resin. The PMUF resin also showed both similar and different fractions present during manufacturing and during short term ageing at ambient temperature. While similarities in recurrent fractions and in trends are common to all the three different formulations, differences between them are also clearly observed. A major proportion of the reaction of some of the aminoplastic resins examined also occurs on ageing (i.e.“maturing” of the resin at ambient temperature), this appearing to be an essential phase of the resin preparation process. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4842–4855, 2006     

三聚氰胺添加方式对MUF胶粘剂性能的影响

以三聚氰胺作为脲醛树脂(UF)的共聚改性剂制备MUF(三聚氰胺甲醛树脂)胶粘剂。探讨了三聚氰胺的添加方式对MUF胶粘剂性能的影响,同时对其固化特性、分子结构和耐热性等进行了分析。结果表明:三聚氰胺2次投料法可有效降低MUF胶粘剂的甲醛释放量,但其胶接强度也随之下降;同时,该MUF固化体系的外推固化温度、表观活化能和反应级数均有所增加,耐热性降低;另外,2次投料体系使MUF的相对分子质量降低、相对分子质量分布变宽。