新型UV固化木器涂料的合成及性能研究

乙醇为溶剂,偶氮二异丁腈(AIBN)为引发剂,引发邻苯二甲酸二烯丙酯(DAP)聚合.聚合工艺为饥饿滴加法加入反应原料DAP、乙醇、AIBN,反应温度为85℃,反应时间约4 h.反应收率约34%,聚合物是可溶的预聚体.预聚体的凝胶色谱、红外光谱图及碘值都显示其具备进一步交联固化的潜力.然后,以合成的邻苯二甲酸二烯丙酯预聚...     

邻苯二甲酸二烯丙基酯树脂固化特性的研究

运用示差扫描量热(DSC)法研究了邻苯二甲酸二烯丙基酯(DAP)树脂的固化反应历程。讨论了引发剂对DAP固化特性的影响,并由DSC曲线得到了DAP树脂的固化工艺和动力学参数。通过固化度、FT-IR的测试对DAP树脂在中温条件下的固化情况进行了研究。结果表明:在过氧化二异丙苯(DCP)固化体系中引入BPO可以使DAP树脂在更低温度下引发固化;在BPO、DCP用量均为2%的条件下,确定了体系的凝胶温度、固化温度、后处理温度分别为:100.5℃,124.3℃,137.8℃,表观活化能为129.3 kJ/mol,反应级数为0.950。固化度、FTIR的测试结果表明:DAP树脂在中温条件下可以固化得较完全。     

新型UV固化可剥性金属涂料的合成及性能研究

选用乙醇为溶剂,偶氮二异丁腈(AIBN)为引发剂,引发邻苯二甲酸二烯丙酯(DAP)聚合。聚合工艺为DAP100g,乙醇30g,AIBN2g,反应温度为80℃,反应时间约4h。反应过后,DAP的收率达29.7%,聚合物是可溶的预聚体。预聚体的凝胶色谱、红外谱图及碘值都显示其具备进一步交联固化的潜力。然后,以合成的邻苯二甲酸二烯丙酯预聚体(P-DAP)为主要成膜物,二缩三丙二醇二丙烯酸酯(TPGDA)为活性稀释剂,双(2,4,6-三甲基苯甲酰基)苯基氧化膦(BAPO)为光引发剂,制备出新型的紫外光固化可剥性涂料。固化后的涂层具有良好的柔韧性、硬度、耐水、耐酸碱、耐汽油的性能,并且可剥性较好。     

邻苯二甲酸二烯丙酯的合成研究

用邻苯二甲酸钠水溶液与氯丙烯为原料,以氯化亚铜为催化剂合成了邻苯二甲酸二烯丙酯.通过实验考察了反应温度、催化剂用量、反应时间以及物料配比对反应的影响.结果表明,最佳反应条件是:反应温度55℃,pH9～10,氯化亚铜加入量为邻苯二甲酸钠6%,反应时间3.0 h,n(氯丙烯):n(苯酐)＝2.4:1.在此条件下,产品最大收...     

邻苯二甲酸酐与烯丙醇酯化反应动力学

为给邻苯二甲酸二烯丙酯的中试放大乃至工业生产提供必要的动力学数据支持,在前期工艺探讨与优化工作基础之上,文中较为系统地研究了无催化剂和以对甲苯磺酸为催化剂条件下,邻苯二甲酸酐与烯丙醇合成邻苯二甲酸二烯丙酯的反应动力学.经模型简化,分别得出了第2步关键反应在这2种反应条件下的反应级数、反应速率常数、表观活化能和指前因子....     

EP基粉末涂料用固化促进剂的合成及固化动力学研究

以甲苯二异氰酸酯(TDI)和3-二甲氨基丙胺为单体、甲苯为溶剂,合成了一种环氧树脂(EP)基粉末涂料用固化促进剂甲苯-2,4-二[N,N-二甲氨基丙脲]。以凝胶时间为衡量指标,优选出促进剂的最佳用量。采用动态DSC(差示扫描量热)法研究了EP/固化剂/促进剂体系的固化反应动力学,并运用温度-升温速率(T-β)外推法求得该体系的固化工艺参数。结果表明:促进剂的最佳质量分数为3%(相对于EP而言),涂膜在165℃/5 min条件下可完全固化;EP/固化剂/促进剂体系的表观活化能为80.295 kJ/mol,反应级数为0.92,凝胶温度为64℃,固化温度为133℃,后固化温度为190℃。     

DGEBF/DDS体系固化动力学机理的研究

以4,4′-二氨基二苯砜(DDS)胺类固化剂固化9,9-二[4-(2,3环氧丙氧基)苯基]芴(DGEBF),采用非等温DSC法推导了固化反应参数和固化机理,并用原位红外和移动窗口二维相关红外分析对固化机理和固化模式进行了验证。结果表明:DGEBF/DDS体系固化反应的表观活化能为64.08 kJ/mol,扩散因子为4.05×104s-1,反应级数为1.55;固化工艺为150℃/1.5 h+190℃/2 h+220℃/1.5 h;固化模式为枝状成核的自催化反应;固化机理为伯胺先与环氧基反应生成仲胺,肿胺继续与环氧基反应生成叔胺,2个反应同时进行,以及在高温下的羟基与环氧基的自催化反应,交联的固化网络逐渐形成。     

邻苯二甲酸二烯丙酯的合成研究

以烯丙醇和邻苯二甲酸酐为原料,合成了邻苯二甲酸二烯丙酯,并用IR1、HNMR对邻苯二甲酸二烯丙酯进行了结构表征。系统研究了烯丙醇和邻苯二甲酸酐的摩尔比、对甲苯磺酸用量、阻聚剂种类及用量、带水剂用量对反应的影响,得到的较佳反应条件(以邻苯二甲酸酐0.1 mol计),即:醇酐摩尔比2.4∶1,对甲苯磺酸0.8 g,4-羟基-2,2,6,6-四甲基哌啶氮氧自由基0.32 g,甲苯35 mL,在回流条件下反应至无水生成,在该条件下产物收率可达96.5%。     

邻苯二甲酸二烯丙酯的合成

以烯丙醇和邻苯二甲酸酐为原料,合成了邻苯二甲酸二烯丙酯,并用IR1、HNMR对邻苯二甲酸二烯丙酯进行了结构表征。系统研究了烯丙醇和邻苯二甲酸酐的摩尔比、对甲苯磺酸用量、阻聚剂种类及用量、带水剂用量对反应的影响,得到的较佳反应条件(以邻苯二甲酸酐0.1 mol计),即:醇酐摩尔比2.4∶1,对甲苯磺酸0.8 g,4-羟基-2,2,6,6-四甲基哌啶氮氧自由基0.32 g,甲苯35 mL,在回流条件下反应至无水生成,在该条件下产物收率可达96.5%。     

CE2908聚酯粉末涂料固化反应特性

用示差扫描量热法(DSC)在动态条件下对CE2908聚酯/异氰尿酸三缩水甘油酯(TGIC)体系的固化反应动力学进行了研究。运用温度-升温速率图外推法确定了该体系的特征参数∶凝胶温度(T0)、固化温度(Tp)和后固化温度(Tf)分别为113℃、146℃和195℃。采用Kissinger方程和Crane方程计算CE2908聚酯/TGIC酯体系的动力学参数,平均表观活化能Ea为62.32 kJ/mol、频率因子A为8.50×106min-1、反应级数n为0.95。建立了该树脂体系的固化动力学模型。利用所建立的固化动力学方程分别讨论了等温和动态条件下CE2908聚酯/TGIC的固化反应特性,为优化聚酯/TGIC体系粉末涂料固化工艺提供了理论依据,并在生产工艺中验证了其正确性。     

Diallyl orthophthalate as a reactive plasticizer for improving PVC processibility. Part I: Polymerization kinetics

The thermal radical curing of four diallylic monomers were studied and was found to be very similar. Dynamic DSC of diallyl orthophthalate (DAOP) showed a strong correlation between the cure rate and the half life temperature of the initiator employed. The extent of allylic cure was found by DSC to be very dependent on the reactivity of the initiator due to a dead-end effect, and to rise towards a plateau value with increasing initiator levels. DAOP was blended with poly(vinyl chloride) (PVC) in various weight ratios by both solution and melt compounding. The compatibility between DAOP and PVC was analysed by measuring the glass transition temperatures of mixtures with dynamic mechanical thermal analysis which showed that DAOP monomer and PVC were fully miscible regardless of the composition. The cure rate of the DAOP/PVC blends was found by dynamic DSC and isothermal NIR to increase with higher levels of PVC due to a gel effect accentuated by grafting to the PVC, while the final extent of cure decreased because of topological constraints.     

Diallyl orthophthalate as a reactive plasticizer for improving PVC processibility, Part II: Rheology during cure

Rheological investigations of blends of PVC (polyvinyl chloride) and DAOP (diallyl orthophthalate) with and without free radical initiators have been conducted under steady and dynamic shearing modes. The results showed that the added DAOP acted as a reactive plasticizer for improving PVC processing, thus greatly decreasing the risk of the decomposition of PVC. The viscosity of the uncured blends was also significantly reduced and obeyed the log-additivity rule with the weight percentage of DAOP. Dynamic rheology of some of the uncured blends indicated the physical gel-like behaviour due to the presence of small crystallites acting as physical crosslinks. Blends with low levels of PVC obeyed the Winter-Chambon gelation criteria and the viscosity diverged at the gel point during the DAOP polymerization, but when the PVC level exceeded 20 wt% the tan δ did not exhibit a frequency independence and the viscosity remained finite up to the end of the reaction. This unusual behaviour is consistent with heterogeneous gelation due to either phase separation between DAOP and PVC components or the non-fractal nature of the gel structure.     

纳米SiO_2改性EP/BMI/CE树脂体系固化动力学研究

采用非等温差示扫描量热(DSC)法对纳米二氧化硅/环氧树脂/双马来酰亚胺/氰酸酯(nano-SiO2/EP/BMI/CE)树脂进行了固化反应动力学和固化工艺研究。通过Kissinger法和Ozawa法求得了nano-SiO2/EP/BMI/CE树脂体系固化反应动力学的表观活化能。结果表明:改性CE树脂体系的固化工艺参数为凝胶温度112℃、固化温度195℃及后处理温度213℃,进而确定了改性CE树脂体系的最佳固化工艺条件为"150℃/3 h→180℃/3 h→200℃/2 h";改性CE树脂体系的平均表观活化能为59.90 kJ/mol。     

POSS改性BMI树脂固化动力学及固化工艺研究

以双马来酰亚胺(BMI)、二烯丙基双酚A(BA)和七苯基倍半硅氧烷三硅醇(POSS-triol)为原料,采用非等温差示扫描量热(DSC)法研究了BMI/BA/POSS-triol体系的固化反应过程。运用Kissinger极值法、Crane法、Flynn-Wall-Ozawa(FWO)等转化率法和T-β(温度-升温速率)外推法确定了改性树脂体系的固化反应动力学参数和固化工艺参数。结果表明:改性树脂体系的固化反应活化能和反应级数(接近于1)均随POSS-triol用量增加而变化不大,说明POSS-triol的加入并没有明显改变BMI/BA体系的固化反应机理;改性树脂体系的凝胶温度为175.7℃,固化温度为226.9℃,后处理温度为271.7℃。     

Diallyl orthophthalate as a reactive plasticizer for improving PVC processability, Part III: Curing, properties, and phase separation

Diallyl orthophthalate (DAOP) is investigated as a reactive plasticizer to aid the processing of PVC by reducing the melt's viscosity and thus minimizing the processing temperature so that decomposition of PVC can be effectively avoided during time-consuming processing operations such as rotational moulding. A range of PVC/DAOP blends have been prepared with dicumyl peroxide (DCP) or cumyl hydroperoxide (CHP) as radical initiators, and their chemorheology, properties and morphology have investigated by dynamic rheometry, DMTA, SEM and solvent resistance. DCP was found to be a better initiator than CHP for polymerization of DAOP in blends with PVC because the former's high decomposition temperature matches well with the processing temperature of the PVC/DAOP blends. DMTA indicates that the T_g of the cured PVC/DAOP blends are very close to that of PVC and have a higher storage modulus at the rubbery region. SEM images show that phase separation occurs during cure of the blend and that solid poly(DAOP) nano-particles are embedded in the PVC continuous phase when the PVC content is more than 30 wt%. This cure and phase separation of DAOP from the PVC matrix can successfully recover the PVC's thermal-resistance properties.     

低温固化改性BMI树脂基体动力学研究

采用催化剂、3,3′-二烯丙基双酚A(DP)和多官能团单体C改性4,4′-二氨基二苯甲烷双马来酰亚胺(BMI)树脂,制取低温固化、高温性能优良的改性BMI树脂。采用差示扫描量热法(DSC)研究了改性BMI树脂的固化反应动力学,计算了固化反应体系的动力学参数,进而提出了该改性BMI树脂固化成型过程的动力学模型,并结合傅里叶红外光谱(FT-IR)对反应机理进行了探讨。研究结果表明,催化剂对固化反应的进行有重要的促进作用,改性BMI树脂的固化温度由259℃降为178℃;烯丙基与马来酰亚胺基的"ene"反应非常显著,且改性剂C与DP的"ene"反应历程相似;改性BMI树脂的固化工艺确定为120℃×6h+140℃×2h+160℃×2h+180℃×2h,后处理工艺为200℃×6h。     

环氧改性氰酸酯树脂固化动力学的研究

采用示差扫描量热法(DSC)对缩水甘油醚类环氧树脂(E-51)与脂环族环氧树脂(R-122)共同改性的双酚A型氰酸酯(BADCy)树脂的固化反应历程进行了研究。由Kisserger方程求得共聚体系固化反应的表观活化能为60.5 kJ/mol,根据Crane理论求得固化反应级数为0.89,接近于1级反应。该体系起始固化温度为132.1℃,峰顶固化温度为168.7℃,终止固化温度为246.0℃。研究表明,环氧树脂可促进BADCy的固化,改性体系可在177℃以下实现较完全固化。     

改性BMI/苯并噁嗪树脂固化反应特性研究

以双马来酰亚胺(BMI)作为苯并噁嗪(BZ)树脂的改性剂,采用非等温差示扫描量热(DSC)法及Freeman-Carroll法研究了改性BMI/BZ树脂体系的反应特性和固化反应动力学过程。结果表明:改性BMI/BZ树脂体系的凝胶时间随BMI用量增加而缩短;改性BMI/BZ树脂体系的固化反应只有一个放热峰,其峰顶温度(230℃左右)明显低于纯BZ体系,并且与BMI用量无关;改性BMI/BZ树脂体系的固化反应近似于1级反应,当w(BMI)=30%~50%时,所建立的固化反应动力学模型在10℃/min时能较好描述改性树脂体系的固化反应过程。     

乙酰丙酮镍催化含硅芳炔树脂的固化反应行为

通过凝胶时间测定、差示扫描量热分析、FT-IR分析研究了乙酰丙酮镍催化含硅芳炔树脂体系的固化反应行为,并计算了反应动力学参数. 结果表明,乙酰丙酮镍对含硅芳炔树脂固化有显著的催化作用,加入0.2%(w)乙酰丙酮镍可较大幅度降低树脂固化反应的活化能和温度,初始固化温度降低约35℃,固化反应活化能为104.2 kJ/mol,比含硅芳炔树脂的固化活化能(121.2 kJ/mol)低;乙酰丙酮镍催化含硅芳炔树脂可发生Glaser偶合、Strauss偶合、环三聚、Diels-Alder和固化反应;树脂固化物保持优异的热稳定性,在氮气气氛下5%失重温度为620℃, 1000℃时残留率为87.8%.