Publication: Alev geciktirici katkı içeren polipropilen kompozitlerin karakterizasyonu ve yanma özelliklerinin incelenmesi
Abstract
Bu çalışmada polipropilen homopolimere magnezyum hidroksit ile Huntit/ Hidromagnezit iki farklı alev geciktirici beraber kullanılarak sinerjik bir etki oluşturarak polipropilen yapısında beraber kullanılması hedeflenmiştir. Polipropilen bu katkılar ile uyumsuz olacağından homojeniteyi sağlamak için uyumlaştırıcı olarak % 3 oranında PP-g-MAH kullanılmıştır. Farklı oranlarda alev geciktiricili karışımlar eş yönlü dönen çift vidalı ekstrüderde eriyik harmanlama yöntemi ile hazırlanmış, enjeksiyon kalıplama ile numuneler üretilmiştir.Numunelere; sınırlayıcı oksijen indeksi (LOI), ısı salınım derecesi (HRR), UL-94 dikey yanma testi, kızgın tel deneyi (GWT), termogravimetrik analiz (TGA), diferansiyel taramalı kalorimetre (DSC), gaz piknometresi ile yoğunluk ölçümü, taramalı elektron mikroskopu (SEM), çekme testi, 3 nokta eğme testi, Charpy darbe dayanımı, sertlik testi, kül tayini ve eriyik akış indeksi (MFI) testleri yapılmıştır.Sinerjitik etki ile 18 olan LOI değeri 21’e yükselmiş, yanma anında ortama salınan ısı % 40,6 oranında azalmış, TGA analizleriyle numunelerin bozunma başlangıç sıcaklığında düşüş, bitiş sıcaklığında ise artışa neden olmuştur. Diğer termal testlerde de başarılı sonuçlar elde edilmiştir.Mekanik testler değerlendirildiğinde ise darbe dayanımı, elastik modül, % uzama ve % eğilme değerlerinde düşüşler gözlemlenmiş, çekme dayanımda gözlemlenen düşüş ise alev geciktirme özellikleri göz önüne alındığında tolere edilebilir düzeydedir. Eğme dayanımı ve eğme maksimum kuvvet dayanımında bir miktar iyileşmeler gözlemlenmiştir.Ayrıca bu iki katkı maddesi kendi aralarında kıyaslandığında Huntit/ Hidromagnezit magnezyum hidroksite göre daha iyi yanma ve mekanik özelliklere sahip olduğu belirlenmiştir.
In this study, it was aimed to use polypropylene homopolymer magnesium hydroxide and Huntite/ Hydromagnesite together with two different flame retardants, creating a synergistic effect, and using them together in the polypropylene structure. Polypropylene and these additives are not compatible with each other. Hence, PP-g-MAH is used as a compatibilizer to obtain homogenous compounds. These compounds with different proportions of flame retardant were prepared by the melt blending technique in a co-rotating twin-screw extruder. Test samples have been produced by injection molding. Afterward, limiting oxygen index (LOI), heat release degree (HRR), UL-94 vertical burning test, hot wire test (GWT), thermogravimetric analysis (TGA) analyses, differential scanning calorimetry (DSC), density measurement with gas pycnometer, scanning electron microscope (SEM), tensile test, 3 point bending, Charpy impact test, hardness test, determination of ash and melt flow index (MFI) were performed to determine the product performance.With the synergistic effect, the LOI value increased from 18 to 21, the heat released to the environment at the time of combustion decreased by 40.6%, and TGA analyzes caused a decrease in the starting temperature of the samples and an increase in the ending temperature. Satisfactory results were also obtained in other thermal tests.When the mechanical tests were evaluated, decreases were observed in the impact strength, elastic modulus, % elongation, and % bending values, and the decrease observed in the tensile strength was at a tolerable level considering the flame retardant properties. Some improvement in flexural strength and flexural maximum strength was observed.In addition, when these two additives were compared among themselves, it was determined that Huntite/ Hydromagnesite had better combustion and mechanical properties than magnesium hydroxide
In this study, it was aimed to use polypropylene homopolymer magnesium hydroxide and Huntite/ Hydromagnesite together with two different flame retardants, creating a synergistic effect, and using them together in the polypropylene structure. Polypropylene and these additives are not compatible with each other. Hence, PP-g-MAH is used as a compatibilizer to obtain homogenous compounds. These compounds with different proportions of flame retardant were prepared by the melt blending technique in a co-rotating twin-screw extruder. Test samples have been produced by injection molding. Afterward, limiting oxygen index (LOI), heat release degree (HRR), UL-94 vertical burning test, hot wire test (GWT), thermogravimetric analysis (TGA) analyses, differential scanning calorimetry (DSC), density measurement with gas pycnometer, scanning electron microscope (SEM), tensile test, 3 point bending, Charpy impact test, hardness test, determination of ash and melt flow index (MFI) were performed to determine the product performance.With the synergistic effect, the LOI value increased from 18 to 21, the heat released to the environment at the time of combustion decreased by 40.6%, and TGA analyzes caused a decrease in the starting temperature of the samples and an increase in the ending temperature. Satisfactory results were also obtained in other thermal tests.When the mechanical tests were evaluated, decreases were observed in the impact strength, elastic modulus, % elongation, and % bending values, and the decrease observed in the tensile strength was at a tolerable level considering the flame retardant properties. Some improvement in flexural strength and flexural maximum strength was observed.In addition, when these two additives were compared among themselves, it was determined that Huntite/ Hydromagnesite had better combustion and mechanical properties than magnesium hydroxide