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The Raman spectra of cis-1,4-, truris-l,4-, and 3,4poIyisoprene are presented, and the frequencies are classified by configurational structure type. The stretching frequency of the carbon-carbon double bond vibrations are used to describe structure content. Only Raman bands characteristic of total 1,4 content and total vinyl content can be observed. Tentative values of structure content determined by both peak height and peak area are presented for two mixed structure rubbers.he polymerization of 1,3-polyisoprene can proceed T by either 1,4 addition or vinyl addition. In the

Polarized infrared measurements were made on polymer samples to obtain the structural changes occurring during the orientation process. The absorbances of the infrared bands were measured by determining the three components of the absorbance. Two components were obtained directly with plane‐polarized light while the third is obtained by tilting the sample and extrapolating. Corrections were made for machine optics polarization, sample birefringence, polarizer inefficiency, anisotropy of the index of refraction, and scattering from the film surface. Data are reported for polyethylene obtained from cold‐drawn specimens as a function of draw temperature. Polyethylene exhibits no strain‐induced crystallization as a result of the chain‐alignment process. Annealing of the drawn samples reperfects the distorted crystals.

Atactic polystyrene was examined by argon ion laser-excited Raman scattering. Depolarization measurements of oriented and unoriented polystyrene were made. An analysis is made of the depolarization measurements in terms of the orientation of the sample. Comparisons are made with dichroic measurements made by infrared. Utilizing Raman and infrared polarization data on oriented polystyrene, some changes in band assignments have been made.