机构地区: 华南理工大学材料科学与工程学院
出 处: 《石油化工》 2005年第12期1159-1163,共5页
摘 要: 以过氧化苯甲酰(BPO)为引发剂,在非隔氧条件下,研究了马来酸酐(MAH)和苯乙烯(St)两种单体在胶乳体系中对天然橡胶(NR)的接枝改性。采用傅里叶变换红外光谱对接枝产物进行定性表征;采用化学滴定法测定MAH的接枝率和接枝效率。实验结果表明,当天然胶乳(总固含量为60%)用量为50 g、BPO用量为0.5 g、MAH和St两种单体用量均为1.0 g、反应温度80℃下反应4 h时,可制备MAH接枝率为1.78%的马来酸酐-苯乙烯双单体接枝天然橡胶(NR-g-(MAH-St)),MAH的接枝效率为57.85%;St单体的引入可以提高MAH单体在NR大分子链上的接枝率和接枝效率。示差扫描量热分析结果表明,接枝后的NR的玻璃化转变温度变化不大,但结晶度较接枝改性前略有提高。 Natural rubber (NR) modified by graft copolymerization with maleic anhydride ( MAH ) and styrene (St) ( NR-g- (MAH- St))was prepared from natural rubber latex with benzoyl peroxide(BPO) as initiator. Fourier transform infrared spectrometry (FFIR) characterization of the NR - g - ( MAH - St) product confirmed that MAH and St were grafted onto NR. MAH graft ratio and graft efficiency was determined by titration. Under optimal reaction conditions for preparation of NR - g - (MAH - St) :4 h, 80 ℃, NR latex (60% solid mass fraction)50 g,MAH 1.0 g,St 1.0 g and initiator BPO 0.5 g,MAH graft ratio and graft efficiency were 1.78% and 57. 85%, respectively. Addition of St could promote reaction of MAH with NR. Differential scanning calorimetry( DSC ) characterization showed that glass transition temperature of NR - g - ( MAH - St) was approximately equal to that of pure NR,but its crystallinity somewhat increased.
关 键 词: 马来酸酐 苯乙烯 过氧化苯甲酰 天然橡胶 接枝率 接枝效率 制备
领 域: [化学工程]