【作者】 江海红；

【导师】 金日光； 周亨近；

【作者基本信息】 北京化工大学 ， 材料学， 2000， 博士

【摘要】 聚酯（PET）纤维以其高强度、尺寸稳定、耐化学腐蚀等优异的性能，在服装、地毯及装饰织物方面具有非常广泛的用途。但聚酯纤维属于熔融性可燃纤维，对聚酯纤维进行阻燃化处理，降低聚酯织物在火灾中的危险性，已成为了一个广泛关注的研究方向。本文通过对国内外几十种新型添加型阻燃剂的筛选，最终确定了溴化磷酸酯（阻燃剂A）、溴化聚芳烃（阻燃剂B）以及聚苯基膦酸酯（阻燃剂C）为制备阻燃涤纶（PET纤维）的阻燃添加剂。聚酯切片与高浓度阻燃剂熔融共混挤出制成阻燃母粒，阻燃母粒再加入纯切片中一起熔融纺丝，纺制成阻燃PET纤维。 应用极限氧指数仪、锥形量热仪（CONE）、热重分析仪（TG）、差热扫描量热仪（DSC）及毛细管流变仪对阻燃样品进行分析测试，研究了阻燃剂的加入对PET的燃烧、热稳定、结晶及流变性能的影响。结果表明： 三种阻燃剂的加入均对PET产生了明显的阻燃效果。阻燃PET的极限氧指数均大于27。聚合型阻燃剂溴化聚芳烃的极限氧指数在三种阻燃剂中最高。应用锥形量热仪（CONE）对阻燃样品及纯PET进行的综合燃烧性能评价结果表明：阻燃样品的热释放总量（THE）、有效燃烧热（EHC）及热释放速率（RHR）较未阻燃的纯PET有了显著降低。其中溴化磷酸酯使RHR降低最为明显，其次是聚苯基膦酸酯，再次是溴化聚芳烃。三种阻燃剂的加入均使阻燃PET的发烟量有所增大。但聚苯基膦酸酯阻燃剂可使PET的烟比率（SR）下降。 阻燃样品的特性粘度和平均聚合度比纯PET有所降低且随着阻燃剂含量的增加，特性粘度呈下降趋势。但总的来说降低的幅度不大，基本在0.58～0.64之间，可以满足聚酯加工及纺丝的粘度要求。其中，含有聚苯基膦酸酯的阻燃样品特性粘度降低最小。热降解动力学研究表明溴化磷酸酯阻燃剂，有促进PET热降解的趋势；含聚合型阻燃剂溴化聚芳烃和聚苯基膦酸酯的阻燃样品对PET的降解促进作用很小。PET的降解是一个复杂的过程，降解表观活化能可分三个区间求取。溴化磷酸酯阻燃剂的加入，使相应区间的降解活化能降低，增大了降解反应速度。 在裂解气相色谱／质谱联用技术及CONE实验结果基础上首次提出了PET双相裂解机理：PET的高温裂解由聚酯大分子链上的酯键的无规断裂开始，形成羰基酸和乙烯基酯的大分子链碎片。断裂大分子链端邻近羰基和乙烯基的酯键持续断裂，不断地形成小分子裂解产物，如：CH₂=CHOCOPhCOOCH=CH₂、CH₂=CHOCOPhCOOH以及HOOCPhCOOH，这些产物还会进一步裂解成分子量更低北京化工大学博士学位论文的小分子裂解产物，如:HooePheoeH3、PheooH、PhH、PhcoeH3以及CO、C02等，与此同时，一部分乙烯基醋端基的大分子链碎片会发生支化而相互连接，再经“链脱离”和环化反应形成难燃的交联产物。澳化聚芳烃遵循气相阻燃机理，而澳化磷酸酷和聚苯基麟酸醋在气相和固相均有阻燃作用。 阻燃样品的特征温度:玻璃化温度Tg、冷结晶温度Tgc、熔点Tm以及熔融结晶温度Tmc均比纯PET有所降低。澳化聚芳烃阻燃剂对PET的熔融、结晶过程的影响程度较小。非等温结晶动力学研究表明，阻燃剂的加入使PET的冷结晶速率加快，而降温结晶速率变慢。浪化聚芳烃阻燃剂的加入改变了PET的结晶和成核机理。 阻燃样品及纯PET的表观粘度均随剪切速率的增加而下降，n值均小于1，表现出明显的切力变稀的假塑性行为，阻燃样品的表观粘度均小于纯PET，但不同的阻燃剂对粘度的降低程度有所不同，滨化磷酸醋的加入对PET的粘度影响比较大，芳香族澳化物及溟化聚芳烃对PET的粘度影响较小。随着温度的升高及阻燃剂含量的增加，各阻燃样品的表观粘度值下降。 阻燃样品具有较好的可纺性。阻燃PET纤维的强度性能虽然较未阻燃化处理的PET纤维有所下降，但绝大部分阻燃纤维的强度性能均己经达到了国标GB8960一88规定的强度指标。其中，添加澳化聚’芳烃的阻燃纤维不但极限氧指数（LOI）值较高，而且阻燃剂添加量为3%和5%的纤维还达到了一级品的标准。添加聚合型澳化聚芳烃阻燃剂的纺丝样品的性能比纯PET下降较小，聚苯基麟酸酷阻燃剂次之;澳化磷酸酷阻燃剂使PET纤维的性能下降较大，但仍可满足纺丝后加工及纤维一般用途的要求。 本文首次将第四统计力学一JRG群子统计理论应用于高聚物燃烧及发烟过程的研究领域。认为聚合物的燃烧过程是体系中燃烧群与凝聚群之间相互竞争的结果;聚合物的发烟过程是体系中无烟群与发烟群之间相互竞争的结果。建立了燃烧及发烟性能的群子方程和群子模型并通过对阻燃PET的实验燃烧及发烟性能结果的群子统计分析，验证了群子理论的合理性，并对阻燃PET燃烧性能与燃烧机理及群子参数之间的关系进行了研究。研究结果对于高聚物阻燃领域的研究具有重要的参考价值。关键词:阻燃、PET、纤维、燃烧、燃烧机理、群子一一--一一----一-一一--一一-一-一--一一一--一一- II更多还原

【Abstract】 Polyester (PET) fibers, because of their outstanding characteristics of high strength, resistance to shrinkage and stretch, good dyeability, and chemical resistance, are used extensively in clothes, carpets and furnishings. However polyester fibers belong to melting flammable fibers. Flame-retarded treatment of PET fibers has become to a research tendency of great concern in reducing the dangers of PET fibers involving fire incidents. This research deals with the preparation of flame-retarded PET resins and fibers by using new types of flame-retardant additives: brominated phosphate compound (FR-A), brominated aromatic polymer (FR-B) and polybenzphosphonate(FR-C) by means of melt extrusion, and than flame-retarded PET fibers were made by adding high flame retradant contents master batch in pure PET chips.The effects of flame-retardants on combustion, thermal degradation, crystallization and rheological propertives of PET have been investigated using L0I tester, CONE Calorimeter, Thermogravimetric Analysis, Differential Scanning Calorimetry and Instron 3211 capillary rheometer separately. Some conclusions can be drawn as follows:The limited oxygen index (LOI) of flame retarded PET which contain three kinds of flame retradants obviously higher (all above 27) than the untreated sample. FR-A has made the greatest increase in LOI of flame-retarded samples comparing with the pure PET. All combustion parameters (such as THE, EHC, RHR) of flame-retarded samples measured from CONE calorimeter were strongly depressed after adding flame-retardants. FR-A has been proved very effective. Next is FR-C and then is FR-B. The SEA parameter increases by adding flame-retardants indicating that more smoke has produced due to the presence of FR. Smoke Ratios grow when adding FR-A and FR-B, but decrease when adding FR-C.The intrinsic viscosities and the average degrees of polymerization of flame retarded PET are lower than the untreated sample and reduce the values with the increase of FR contents. But because there are not a significant changing in intrinsic viscosities in general, the values basically between 0.58~0.64, the requirements of processing and spinning can be met. The intrinsic viscosities of flame-retarded samples that contain FR-C have the lowest decrease. Borminated phosphate FR has obviously accelerated the degradation rate of PET and this also has been proved by the degradation kinetics analysis. This kind of accelerate degradation phenomenonreduce when using FR-B and FR-C instead. The degradation was found to be a complex process of at least three overlapping stages for which kinetic calues can be calculated. The results indicate that FR-A has reduced the activation energies and has obviously accelerated the degradation rate of PET.The products of pyrolysis of untreated and flame retarded PET have been studied using gas chromatography/mass spectrometry technique combining with CONE data. A mechanism of two-phase pyrolysis for PET degradation is first timely proposed. The first step in the degradation is most probably the classical ester scission reaction to give a carboxylic acid and olefinic end groups. Further ester scission on the adjacent ester groups of carboxylic acid and olefinic molecular chains can then lead to the formation of lower weight pyrolytic products, such as: CH2=CHOCOPhCOOCH=CH2, CH2=CHOCOPhCOOH and HOOCPhCOOH, and they can pyrolyze continually to produce substrate pyrolytic compounds, such as: HOOCPhCOCH3, PhCOO, PhH, PhCOCH3 and CO, CO2 . At the same time, a corsslinking cyclization reaction occurred of the formation of the gas products during the degradation of PET. This step ultimatly produce a kind of cycloolefin structure. FR-B involved only gas-phase mechanism, while FR-A and FR-C involved both gas-phase and solid-phase mechanism.Tg,Tgc,Tm,Tmc of flame retarded samples have been reduced by the presence of flame-retardants. They also make the crystallization of PET easier during low temperature range, but more difficult among high temperature range. FR-B has the smallest infl更多还原